System and method for investigating sub-surface features of a rock formation.
Abstract
A method and system for investigating rock formations outside a borehole are provided. The method includes generating a first acoustic wave at a first frequency by a first acoustic source; and generating a second acoustic wave at a second frequency by a second acoustic source. The first and the second acoustic sources are arranged within a localized area of the borehole. The first and the second acoustic waves intersect in an intersection volume outside the borehole. The method further includes receiving a third acoustic wave at a third frequency, the third shear acoustic wave returning to the borehole due to a non-linear mixing process in a non-linear mixing zone within the intersection volume at a receiver arranged in the borehole. The third frequency is equal to a difference between the first frequency and the second frequency.
Term
5.1 yearsleft in the term
Expires 9 November 2031.
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51 claims: 32 independent, 19 dependent
- 1CLAIMS REIVINDICACIONES INSTITUTO MEXICANO M I A OíjNUIac MEXICAN INSTITUTE MIA OíjNUIac INIXISTIUAL INIXISTIUAL Habiéndose descrito la invención como antecede, se reclama como propiedad lo contenido en las siguientes reivindicaciones:Having described the invention as above, the content of the following claims is claimed as property: 1. Un método para generar una imagen tridimensional de una formación de roca, caracterizado porque comprende: one. A method of generating a three-dimensional image of a rock formation, characterized in that it comprises: la generación de una primera señal acústica por una primera fuente acústica, en donde la primera señal acústica comprende una primera pluralidad de pulsos dispuestos en una secuencia de tiempo, la primera pluralidad de pulsos estando separados en el tiempo, cada pulso comprendiendo una primera señal modulada a una frecuencia central, en donde las frecuencias centrales de dos pulsos consecutivos son diferentes;the generation of a first acoustic signal by a first acoustic source, wherein the first acoustic signal comprises a first plurality of pulses arranged in a time sequence, the first plurality of pulses being separated in time, each pulse comprising a first modulated signal at a center frequency, where the center frequencies of two consecutive pulses are different;generating a second acoustic signal by a second acoustic source, wherein the second acoustic signal comprises a second plurality of pulses arranged as a time sequence, the second plurality of pulses being separated in time, wherein a time separation between the two consecutive pulse centers is the same as a time spacing between the corresponding two pulse centers in the first plurality of pulses, where a start time difference is la generación de una segunda señal acústica por una segunda fuente acústica, en donde la segunda señal acústica comprende una segunda pluralidad de pulsos dispuestos como una secuencia de tiempo, la segunda pluralidad de pulsos siendo separados en el tiempo, en donde una separación en tiempo entre los centros de dos pulsos consecutivos es la misma que una separación en el tiempo entre los centros de dos pulsos correspondientes en la primera pluralidad de pulsos, en donde una diferencia de tiempo de inicio se IMPI IMPI IN.ATtTimi MEXICANO iw i * RROfitmc IN'WSTWAl provides between a start time of a transmission of the second plurality of pulses and a start time of a transmission of the first plurality of pulses, wherein each pulse comprises a modulated signal and wherein a center frequency of the modulated signal within each pulse in the second plurality of pulses is a selected fraction of the center frequency of the modulated signal within each corresponding pulse in the first plurality of pulses;IN.ATtTimi MEXICANO iw i* RROfitmc IN’WSTWAl proporciona entre un tiempo de inicio de una transmisión de la segunda pluralidad de pulsos y un tiempo de inicio de una transmisión de la primera pluralidad de pulsos, en donde cada pulso comprende una señal modulada y en donde una frecuencia central de la señal modulada dentro de cada pulso en la segunda pluralidad de pulsos es una fracción seleccionada de la frecuencia central de la señal modulada dentro de cada pulso correspondiente en la primera pluralidad de pulsos;en donde la primera fuente acústica y la segunda fuente acústica están dispuestas dentro del barreno y son controlables de tal manera que las trayectorias de la primera y la segunda señales acústicas se crucen en un volumen de intersección fuera del barreno;wherein the first sound source and the second sound source are arranged within the hole and are controllable such that the paths of the first and second sound signals intersect at an intersecting volume outside the hole;receiving, by a receiver arranged in the hole, a detected signal that returns to the hole, the detected signal includes a signal that is generated by a non-linear mixing process from the first acoustic signal and the second acoustic signal in a zone of nonlinear mixing within the intersecting volume;recibir, por un receptor dispuesto en el barreno, una señal detectada que regrese al barreno, la señal detectada incluye una señal que se genera por un proceso de mezcla no lineal a partir de la primera señal acústica y la segunda señal acústica en una zona de mezcla no lineal dentro del volumen de intersección;performing, by a processor, data processing on the received signal to extract the signal generated by the non-linear mixing process on noise or on signals generated by a linear interaction process, or both;and generate a three-dimensional image of a propagation compression velocity, a propagation velocity realizar, por un procesador, el procesamiento de datos en la señal recibida para extraer la señal generada por el proceso de mezcla no lineal sobre ruido o sobre señales generadas por un proceso de interacción lineal, o ambos;y generar una imagen tridimensional de una velocidad de compresión de propagación, una propagación de la velocidad IMPI de cizallamiento, una relación de la velocidad de compresión y la velocidad de cizallamiento, o propiedades no lineales de una formación de roca, o cualquier combinación de dos o más de las mismas con base en la señal generada por el proceso de mezcla no lineal. Shear IMPI, a ratio of the compression rate to the shear rate, or nonlinear properties of a rock formation, or any combination of two or more thereof based on the signal generated by the nonlinear mixing process .
- 2The method according to claim 2. El método de conformidad con la reivindicación 1, caracterizado porque la generación de la primera señal acústica comprende generar la pluralidad de pulsos de tal manera que una separación en el tiempo entre los centros de dos pulsos consecutivos en la primera pluralidad de pulsos sea mayor que una duración de tiempo de cada pulso. 1, characterized in that the generation of the first acoustic signal comprises generating the plurality of pulses in such a way that a separation in time between the centers of two consecutive pulses in the first plurality of pulses is greater than a time duration of each pulse.
- 3The method according to claim 3. El método de conformidad con la reivindicación 1, caracterizado porque la generación de la imagen tridimensional de la velocidad de compresión de propagación, la propagación de la velocidad de cizallamiento, la relación de la velocidad de compresión y la velocidad de cizallamiento, o las propiedades no lineales de la formación de roca, o cualquier combinación de dos o más de las mismas, se lleva a cabo mediante el uso de formación de imágenes de Kirchhoff, formación de imágenes haz o formación de imágenes de ecuación de onda. 1, characterized in that the three-dimensional image generation of the propagation compression rate, the propagation of the shear rate, the ratio of the compression rate and the shear rate, or the nonlinear properties of rock formation, or any combination of two or more thereof, is carried out by using Kirchhoff imaging, beam imaging or wave equation imaging.
- 4El método de conformidad con la reivindicación Four. The method according to claim 3, caracterizado porque comprende además la determinación de un valor de la velocidad de compresión de propagación o un valor de la velocidad de cizallamiento o ambos usando 3, characterized in that it further comprises determining a propagation compression rate value or a shear rate value or both using ΙΜΡΙ ΙΜΡΙ INSTITUTO MEXICANO Dt LA PROPIEDAD INDUSTRIAL inversion of tomographic speed or inversion of complete waveform or by iterative imaging in combination with inversion of tomographic speed. INSTITUTO MEXICANO Dt LA PROPIEDAD INDUSTRIAL inversión de la velocidad tomográfica o inversión de forma de onda completa o por formación de imágenes iterativa en combinación con inversión de velocidad tomográfica.
- 5The method according to claim 5. El método de conformidad con la reivindicación 1, caracterizado porque la generación de la imagen tridimensional de la velocidad de compresión de propagación, la propagación de la velocidad de cizallamiento, la relación de la velocidad de compresión a la velocidad de cizallamiento, o las propiedades no lineales de una formación de roca, o cualquier combinación de dos o más de las mismas, se lleva a cabo usando un método de análisis o asignación que comprende:1, characterized in that the three-dimensional image generation of the propagation compression rate, the propagation of the shear rate, the ratio of the compression rate to the shear rate, or the nonlinear properties of a rock formation, or any combination of two or more thereof, is carried out using an analysis or allocation method comprising: estimar un modelo de velocidad de propagación inicial usando registros de pozos en un barreno y suposiciones acerca de la continuidad lateral de una formación de roca lejos del barreno;estimating an initial propagation velocity model using well logs in a hole and assumptions about the lateral continuity of a rock formation away from the hole;calcular un primer tiempo de viaje de la primera señal acústica de la primera fuente acústica a un centro de la zona de mezcla;calculating a first travel time of the first acoustic signal from the first acoustic source to a center of the mixing zone;calcular un segundo tiempo de viaje de la segunda señal acústica de la segunda fuente acústica al centro de la zona de mezcla;calculating a second travel time of the second acoustic signal from the second acoustic source to the center of the mixing zone;calcular un tercer tiempo de viaje entre el centro de la zona de mezcla y un receptor configurado para recibir una señal detectada que regrese al barreno que tenga una calculate a third travel time between the center of the mixing zone and a receiver configured to receive a detected signal that returns to the hole that has a IMPI frecuencia igual a una diferencia entre la primera frecuencia y la segunda frecuencia, la señal detectada siendo generada por un proceso de mezcla no lineal a partir de la primera señal acústica y la segunda señal acústica en la zona de mezcla;IMPI frequency equal to a difference between the first frequency and the second frequency, the detected signal being generated by a non-linear mixing process from the first acoustic signal and the second acoustic signal in the mixing zone;calcular un tiempo de llegada Tp correspondiente a un tiempo total de viaje de una señal que regrese al barreno mediante la adición del primer tiempo de viaje y el tercer tiempo de viaje, y el cálculo de una diferencia de tiempo de inicio δρ entre el primer tiempo de viaje y el segundo tiempo de viaje;calculating an arrival time Tp corresponding to a total travel time of a signal returning to the hole by adding the first travel time and the third travel time, and calculating a start time difference δρ between the first time travel and the second travel time;extracting from the signal received at the receiver the signals generated by the non-linear mixing process to produce for each start time difference δ and for each frequency relationship d, a correlated signal M (t, δ, d), which is a function of the arrival time t, the start time difference δ and the frequency relationship d, y containing the non-linear interaction signals;extraer de la señal recibida en el receptor las señales generadas por el proceso de mezcla no lineal para producir para cada diferencia de tiempo de inicio δ y para cada relación de frecuencia d, una señal correlacionada M (t, δ, d) , que es una función del tiempo de llegada t, la diferencia de tiempo de inicio δ y la relación de frecuencia d, y que contiene las señales de interacción no lineales;buscar todos los valores de tiempo de llegada t, diferencia de tiempo de inicio δ, y relación de frecuencia d en la señal correlacionada M (t, δ, d) para determinar un valor de tiempo de llegada Tnl, diferencia de tiempo de inicio §nl y relación de frecuencia dm, durante la cual se produce una señal pico de banda limitada generada por el proceso de mezcla no lineal;look up all the arrival time values t, start time difference δ, and frequency relationship d in the correlated signal M (t, δ, d) to determine an arrival time value Tnl, start time difference § nl and dm frequency ratio, during which a limited band peak signal produced by the non-linear mixing process is produced;96 ΙΜΡϊ 96 ΙΜΡϊ INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL comparar el tiempo de llegada Tp .calculado ¿un uir tiempo de llegada medido Tnl y comparar la diferencia de tiempo de inicio calculada δρ con una diferencia de tiempo de inicio medida Snl;MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY compare the arrival time Tp. Calculated ¿uir measured arrival time Tnl and compare the calculated start time difference δρ with a measured start time difference Snl;determinar si el tiempo de llegada Tp calculado es diferente del tiempo de llegada Tnl medido y la diferencia de tiempo de inicio δρ calculada es diferente de la diferencia de tiempo de inicio 8nl medida y, si es así, actualizar el modelo de velocidad de propagación usando una diferencia entre los tiempos de llegada medido y calculado y una diferencia entre las diferencias de tiempo de inicio calculadas y medidas;y repetir iterativamente los pasos anteriores hasta que el tiempo de llegada calculada correspondiente al tiempo total de viaje sea sustancialmente igual a un tiempo de llegada medida, o la diferencia de tiempo de inicio calculada sea sustancialmente igual a una diferencia de tiempo de inicio medida, o ambas, para un intervalo de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, el ángulo de azimut de la primera señal acústica, el ángulo de azimut de la segunda señal acústica, el ángulo de elevación de la primera señal acústica, o el ángulo de elevación de la segunda señal acústica, o cualquier combinación de dos o más de los mismos, para obtener una velocidad de propagación Vp y determine if the calculated arrival time Tp is different from the measured arrival time Tnl and the calculated start time difference δρ is different from the measured start time difference 8nl and, if so, update the propagation velocity model using a difference between measured and calculated arrival times and a difference between calculated and measured start time differences;and iteratively repeating the above steps until the calculated arrival time corresponding to the total travel time is substantially equal to a measured arrival time, or the calculated start time difference is substantially equal to a measured start time difference, or both, for a range of values of the position of the first sound source, the position of the second sound source, the position of the receiver, the azimuth angle of the first acoustic signal, the azimuth angle of the second acoustic signal, the elevation angle of the first acoustic signal, or the elevation angle of the second acoustic signal, or any combination of two or more of the themselves, to obtain a propagation speed Vp and INSTITUTO MEXICANO ϊζί&νκεΞ DE LA PROPIEDAD MEXICAN INSTITUTE ϊζί & νκεΞ OF THE PROPERTY INDUSTRIAL propagation velocity Vs resulting in the calculated arrival time is substantially equal to the measured arrival time or the calculated time difference is substantially equal to the measured start time difference, or both;and generating a three-dimensional image of a propagation compression rate, a shear rate spread, a ratio of the compression rate to the shear rate, or nonlinear properties, or any combination of two or more thereof. INDUSTRIAL velocidad de propagación Vs que resulten enagüe el tiempo da llegada calculado sea sustancialmente igual a el tiempo de llegada medida o la diferencia de tiempo calculada sea sustancialmente igual a la diferencia de tiempo de inicio medida, o ambas;y generar una imagen tridimensional de una velocidad de compresión de propagación, una propagación de la velocidad de cizallamiento, una relación de la velocidad de compresión a la velocidad de cizallamiento, o propiedades no lineales, o cualquier combinación de dos o más de las mismas.
- 6The method according to claim 6. El método de conformidad con la reivindicación 1, caracterizado porque la realización, por un procesador, del procesamiento de datos en la señal recibida para extraer la señal generada por el proceso de mezcla no lineal comprende la extracción de señales generadas por el proceso de mezcla no lineal mediante la correlación de la señal detectada con una señal de plantilla diseñada según las propiedades previstas de la señal de acuerdo con las reglas de selección para mezcla no colineal en un medio no lineal, y repitiendo para una pluralidad de diferencias de tiempo de inicio Ó entre la segunda pluralidad de pulsos y la primera pluralidad de pulsos y para una pluralidad de relaciones de frecuencia d entre la frecuencia central de la señal modulada dentro de cada pulso en la segunda pluralidad de pulsos y la frecuencia central de la señal modulada dentro de cada pulso 1, characterized in that the performance, by a processor, of data processing on the received signal to extract the signal generated by the non-linear mixing process comprises extracting signals generated by the non-linear mixing process by correlating the signal detected with a template signal designed according to the expected properties of the signal according to the selection rules for non-collinear mixing in a non-linear medium, and repeating for a plurality of start time differences Ó between the second plurality of pulses and the first plurality of pulses and for a plurality of frequency relationships d between the center frequency of the modulated signal within each pulse in the second plurality of pulses and the center frequency of the modulated signal within each pulse INSTITUTO MEXICANO Di LA PROPIEDAD MEXICAN INSTITUTE Say THE PROPERTY INDUSTRIAL correspondiente en la primera pluralidad de pulsos, la correlación entre la señal de plantilla y la señal detectada para producir para cada diferencia de tiempo de inicio δ y cada relación de frecuencia d una señal correlacionada M (t, δ, d) que contenga una señal de interacción no lineal. INDUSTRIAL corresponding in the first plurality of pulses, the correlation between the template signal and the detected signal to produce for each start time difference δ and each frequency relationship d a correlated signal M (t, δ, d) containing a nonlinear interaction signal.
- 7The method according to claim 7. El método de conformidad con la reivindicación 5, caracterizado porque comprende además calcular, con base en un modelo de velocidad de propagación, las trayectorias de la primera señal acústica emitida por una primera fuente acústica y la segunda señal acústica emitida por la segunda fuente acústica usando la posición de la primera fuente acústica, el ángulo de elevación y el ángulo de azimut de la primera señal acústica y la posición de la segunda fuente acústica, el ángulo de elevación y el ángulo de azimut de la segunda señal acústica. 5, characterized in that it further comprises calculating, based on a propagation speed model, the trajectories of the first acoustic signal emitted by a first acoustic source and the second acoustic signal emitted by the second acoustic source using the position of the first acoustic source , the elevation angle and azimuth angle of the first acoustic signal and the position of the second acoustic source, the elevation angle and azimuth angle of the second acoustic signal.
- 8The method according to claim 8. El método de conformidad con la reivindicación 7, caracterizado porque comprende además la determinación de una ubicación de una zona de mezcla donde la primera señal acústica y la segunda señal acústica interactúan de forma no lineal con base en la posición de la primera fuente acústica, el ángulo de elevación y el ángulo de azimut de la primera señal acústica y la posición de la segunda fuente acústica, el ángulo de elevación y el ángulo de azimut de la segunda señal acústica. 7, characterized in that it further comprises determining a location of a mixing zone where the first acoustic signal and the second acoustic signal interact non-linearly based on the position of the first acoustic source, the elevation angle and the angle of azimuth of the first acoustic signal and the position of the second acoustic source, elevation angle and azimuth angle of the second acoustic signal.
- 99. El método de conformidad con la reivindicación The method according to claim INSTITUTE INSTITUTO DE LA PROPIEDAD industrial OF INDUSTRIAL PROPERTY 8, caracterizado porque comprende además el cálculo de las coordenadas espaciales de la zona de mezcla donde las dos señales acústicas interactúan de forma no lineal, el cálculo de un ángulo de convergencia entre la primera señal acústica proveniente de la primera fuente acústica y la segunda señal acústica proveniente de la segunda fuente acústica con base en el ángulo de elevación y el ángulo de azimut de la primera señal acústica, y la posición de la primera fuente acústica, y el ángulo de elevación y el ángulo de azimut de la segunda señal acústica, y una posición de la segunda fuente acústica. 8, characterized in that it also includes the calculation of the spatial coordinates of the mixing zone where the two acoustic signals interact non-linearly, the calculation of an angle of convergence between the first acoustic signal from the first acoustic source and the second signal acoustic from the second acoustic source based on the elevation angle and azimuth angle of the first acoustic signal, and the position of the first acoustic source, and the elevation angle and azimuth angle of the second acoustic signal, and a position of the second acoustic source.
- 10The method according to claim 10. El método de conformidad con la reivindicación 9, caracterizado porque comprende además la asignación de la señal correlacionada M (TNl, Ónl, dNL) a las coordenadas espaciales de la zona de mezcla correspondiente a las propiedades no lineales de la formación rocosa en la zona de mezcla. 9, characterized in that it also includes the assignment of the correlated signal M (TNl, Ónl, dNL) to the spatial coordinates of the mixing zone corresponding to the nonlinear properties of the rock formation in the mixing zone.
- 11El método de conformidad con la reivindicación eleven. The method according to claim 10, caracterizado porque comprende además el cálculo de la relación de velocidad entre la velocidad de compresión y la velocidad de cizallamiento en la zona de mezcla a partir de la relación de frecuencia dNL y el ángulo de convergencia usando una relación de reglas de selección entre la relación de velocidad de la velocidad de compresión y la velocidad de cizallamiento, relación de frecuencia y ángulo de convergencia y asignación de la relación de velocidad 10, characterized in that it further comprises calculating the speed ratio between the compression rate and the shear rate in the mixing zone from the dNL frequency ratio and the angle of convergence using a ratio of selection rules between the speed ratio of compression rate and shear rate, frequency ratio and angle of convergence and speed ratio assignment 100 100 INSTITUTO MEXICANO IX LA PROPIEDAD INDUSTRIAL calculada a las coordenadas espaciales de la ~zeina de. imanóla.— MEXICAN INSTITUTE IX INDUSTRIAL PROPERTY calculated at the spatial coordinates of the ~ zeina of. imanóla.—
- 12The method according to claim 12. El método de conformidad con la reivindicación 11, caracterizado porque comprende además la repetición de la asignación de la señal correlacionada M (Tnl, 6nl, ¿nl) a las coordenadas espaciales de la zona de mezcla, o la asignación de la relación de velocidad calculada a las coordenadas espaciales de la zona de mezcla, o ambas, para un intervalo de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, el ángulo de azimut de la primera señal acústica, el ángulo de azimut de la segunda señal acústica, el ángulo de elevación de la primera señal acústica, o el ángulo de elevación de la segunda señal acústica, o cualquier combinación de dos o más de los mismos, para obtener una imagen tridimensional de una fuerza de las propiedades no lineales o una imagen tridimensional de la relación de velocidad, o ambas, mediante la combinación de los valores medidos a través de mediciones repetidas. 11, characterized in that it further comprises repeating the assignment of the correlated signal M (Tnl, 6nl, ¿nl) to the spatial coordinates of the mixing area, or assigning the calculated speed ratio to the spatial coordinates of the area or both, for a range of values of the position of the first sound source, the position of the second sound source, the position of the receiver, the azimuth angle of the first sound signal, the azimuth angle of the second acoustic signal, the elevation angle of the first acoustic signal, or the elevation angle of the second acoustic signal, or any combination of two or more of them, to obtain a three-dimensional image of a force of nonlinear properties or a three-dimensional image of the velocity ratio, or both, by combining the measured values through repeated measurements.
- 13The method according to claim 13. El método de conformidad con la reivindicación 1, caracterizado porque comprende además la determinación de un valor de la velocidad de compresión de propagación, un valor de la propagación de la velocidad de cizallamiento, o un valor de la relación de la velocidad de compresión y la velocidad de cizallamiento, o cualquier combinación de dos o más de las mismas. 1, characterized in that it further comprises determining a value of the propagation compression rate, a value of the propagation of the shear rate, or a value of the ratio of the compression rate and the shear rate, or any combination two or more of them. 101 101 INSTITUTO MEXICANO DE LA l'kOPIEDAl' MEXICAN INSTITUTE OF THE KOPIEDAl ' INDUSTRIAL INDUSTRIAL
- 14The method according to claim 14. El método de conformidad con la reivindicación 1, caracterizado porque determinar el valor de la velocidad de compresión de propagación, el valor de propagación de la velocidad de cizallamiento, el valor de la relación de la velocidad de compresión y la velocidad de cizallamiento, o cualquier combinación de dos o más de los mismos se lleva a cabo usando un método de asignación que comprende:1, characterized in that determining the value of the propagation compression rate, the propagation value of the shear rate, the value of the ratio of the compression rate and the shear rate, or any combination of two or more of the They are carried out using an allocation method that includes: estimar un modelo de velocidad de propagación inicial usando registros de pozo en un barreno y suposiciones acerca de la continuidad lateral de la formación de roca lejos del barreno;estimate an initial propagation velocity model using well logs in a hole and assumptions about the lateral continuity of the rock formation away from the hole;calcular un primer tiempo de viaje de la primera señal acústica de la primera fuente acústica a un centro de la zona de mezcla;calculating a first travel time of the first acoustic signal from the first acoustic source to a center of the mixing zone;calcular un segundo tiempo de viaje de la segunda señal acústica de la segunda fuente acústica al centro de la zona de mezcla;calculating a second travel time of the second acoustic signal from the second acoustic source to the center of the mixing zone;calcular un tercer tiempo de viaje entre el centro de la zona de mezcla y un receptor configurado para recibir una señal detectada que regrese al barreno que tenga una frecuencia igual a una diferencia entre la primera frecuencia y la segunda frecuencia, la señal detectada siendo generada por un proceso de mezcla no lineal a partir de la primera señal acústica y la segunda señal acústica en la zona de mezcla;calculating a third travel time between the center of the mixing zone and a receiver configured to receive a detected signal that returns to the hole that has a frequency equal to a difference between the first frequency and the second frequency, the detected signal being generated by a non-linear mixing process from the first acoustic signal and the second acoustic signal in the mixing zone;102 102 IMPI IMPI INSTITUTO MEXICANO »F LA PROPIEDAD INDUSTRIAL calcular un tiempo de llegada Tp cori?eapondicnt^ a un tiempo total de viaje de una señal que regrese al barreno mediante la adición del primer tiempo de viaje y el tercer tiempo de viaje, y el cálculo de una diferencia de tiempo de inicio δρ entre el primer tiempo de viaje y el segundo tiempo de viaje;INSTITUTO MEXICANO »F LA PROPIEDAD INDUSTRIAL calculate an arrival time Tp cori? Eapondicnt ^ to a total travel time of a signal that returns to the barren or by adding the first travel time and the third travel time, and calculating a start time difference δρ between the first travel time and the second travel time;extracting from the signal received at the receiver the signals generated by the non-linear mixing process to produce for each start time difference δ and for each frequency relationship d, a correlated signal M (t, δ, d), which is a function of the arrival time t, the start time difference δ and the frequency relationship d, y containing the non-linear interaction signals;extraer de la señal recibida en el receptor las señales generadas por el proceso de mezcla no lineal para producir para cada diferencia de tiempo de inicio δ y para cada relación de frecuencia d, una señal correlacionada M (t, δ, d) , que es una función del tiempo de llegada t, la diferencia de tiempo de inicio δ y la relación de frecuencia d, y que contiene las señales de interacción no lineales;buscar todos los valores de tiempo de llegada t, diferencia de tiempo de inicio δ, y relación de frecuencia d en la señal correlacionada M (t, δ, d) para determinar un valor de tiempo de llegada Tnl, diferencia de tiempo de inicio Ónl y relación de frecuencia dNL durante la cual se produce una señal pico de banda limitada generada por el proceso de mezcla no lineal;search all the arrival time values t, start time difference δ, and frequency relationship d in the correlated signal M (t, δ, d) to determine an arrival time value Tnl, start time difference Ónl and dNL frequency ratio during which a limited band peak signal produced by the non-linear mixing process is produced;comparar el tiempo de llegada Tp calculado con un tiempo de llegada medido Tnl y comparar la diferencia de tiempo de inicio calculada δρ con una diferencia de tiempo de inicio medida Snl;comparing the calculated arrival time Tp with a measured arrival time Tnl and comparing the calculated start time difference δρ with a measured start time difference Snl;determinar si el tiempo de llegada Tp calculado es determine if the calculated arrival time Tp is 103 103 INSTITUTO MÉXICAMC nt IA WOeiEDAP INSTITUTO MÉXICAMC nt IA WOeiEDAP INW5TSIAL diferente del tiempo de llegada Tul medido y la aiTSVSHCia dé tiempo de inicio δρ calculada es diferente de la diferencia de tiempo de inicio 6nl medida y, si es así, actualizar el modelo de velocidad de propagación usando una diferencia entre los tiempos de llegada medido y calculado y una diferencia entre las diferencias de tiempo de inicio calculadas y medidas;y repetir iterativamente los pasos anteriores hasta que el tiempo de llegada calculada correspondiente al tiempo total de viaje sea sustancialmente igual a un tiempo de llegada medida, o la diferencia de tiempo de inicio calculada sea sustancialmente igual a una diferencia de tiempo de inicio medida, o ambas, para un intervalo de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, el ángulo de azimut de la primera señal acústica, el ángulo de azimut de la segunda señal acústica, el ángulo de elevación de la primera señal acústica, o el ángulo de elevación de la segunda señal acústica, o cualquier combinación de dos o más de los mismos, para obtener una velocidad de propagación Vp y velocidad de propagación Vs que resulten en que el tiempo de llegada calculado sea sustancialmente igual a el tiempo de llegada medida o la diferencia de tiempo calculada sea sustancialmente igual a la diferencia de tiempo de inicio medida, o ambas. INW5TSIAL different from the measured Tul arrival time and the calculated start time δρ aiTSVSHCia is different from the measured 6nl start time difference and, if so, update the propagation speed model using a difference between the measured arrival times y calculated and a difference between calculated and measured start time differences;and iteratively repeating the above steps until the calculated arrival time corresponding to the total travel time is substantially equal to a measured arrival time, or the calculated start time difference is substantially equal to a measured start time difference, or both, for a range of values of the position of the first sound source, the position of the second sound source, the position of the receiver, the azimuth angle of the first acoustic signal, the azimuth angle of the second acoustic signal, the elevation angle of the first acoustic signal, or the elevation angle of the second acoustic signal, or any combination of two or more of the themselves, to obtain a propagation velocity Vp and a propagation velocity Vs that result in the calculated arrival time being substantially equal to the measured arrival time or the calculated time difference being substantially equal to the measured starting time difference, or both . 104 104
- 15El método de conformidad con la reivindicación fifteen. The method according to claim 14, caracterizado porque comprende además calcular con base en un modelo de velocidad de propagación trayectorias de la primera señal acústica que tenga la primera frecuencia emitida por la primera fuente acústica y la segunda señal acústica que tenga la segunda frecuencia emitida por la segunda fuente acústica usando una posición de la primera fuente acústica, el ángulo de elevación y el ángulo de azimut de la primera señal acústica y la posición de la segunda fuente acústica, el ángulo de elevación y el ángulo de azimut de la segunda señal acústica, y la posición del receptor. 14, characterized in that it further comprises calculating, based on a propagation speed model, the trajectories of the first acoustic signal having the first frequency emitted by the first acoustic source and the second acoustic signal having the second frequency emitted by the second acoustic source using a position of the first sound source, the elevation angle and azimuth angle of the first sound signal and the position of the second sound source, the elevation angle and azimuth angle of the second acoustic signal, and the position of the receiver.
- 16The method according to claim 16. El método de conformidad con la reivindicación 15, caracterizado porque comprende además determinar una ubicación de una zona de mezcla donde la primera señal acústica y la segunda señal acústica interactúan de forma no lineal con base en la posición de la primera fuente acústica, el ángulo de elevación y el ángulo de azimut de la primera señal acústica y la posición de la segunda fuente acústica, el ángulo de elevación y el ángulo de azimut de la segunda señal acústica. 15, characterized in that it further comprises determining a location of a mixing zone where the first acoustic signal and the second acoustic signal interact non-linearly based on the position of the first acoustic source, the elevation angle and the azimuth angle of the first acoustic signal and the position of the second acoustic source, the elevation angle and the azimuth angle of the second acoustic signal.
- 17The method according to claim 17. El método de conformidad con la reivindicación 16, caracterizado porque comprende además calcular las coordenadas espaciales de la zona de mezcla donde las dos señales acústicas interactúan de forma no lineal, calcular un ángulo de convergencia entre la primera señal acústica 16, characterized in that it further comprises calculating the spatial coordinates of the mixing zone where the two acoustic signals interact non-linearly, calculating an angle of convergence between the first acoustic signal 105 105 INSTITUTO MEXICANO DE LA PROPIEDAD MEXICAN INSTITUTE OF PROPERTY INDUSTRIAL from the first sound source and the second sound signal from the second sound source based on the elevation angle and azimuth angle of the first sound signal and the position of the first sound source, and the elevation angle and the azimuth angle of the second acoustic signal and the position of the second acoustic source. INDUSTRIAL proveniente de la primera fuente acústica y la segunda señal acústica proveniente de la segunda fuente acústica con base en el ángulo de elevación y el ángulo de azimut de la primera señal acústica y la posición de la primera fuente acústica, y el ángulo de elevación y el ángulo de azimut de la segunda señal acústica y la posición de la segunda fuente acústica.
- 18The method according to claim 18. El método de conformidad con la reivindicación 17, caracterizado porgue comprende además el cálculo de la relación de velocidad entre la velocidad de compresión y la velocidad de cizallamiento en la zona de mezcla a partir de la relación de frecuencia dNL y el ángulo de convergencia usando una relación de reglas de selección entre la relación de velocidad de la velocidad de compresión y la velocidad de cizallamiento, la relación de frecuencia y ángulo de convergencia, y asignar la relación de velocidad calculada aO las coordenadas espaciales de la zona de mezcla. 17, characterized by porgue further comprises calculating the speed ratio between the compression rate and the shear rate in the mixing zone from the frequency ratio dNL and the angle of convergence using a ratio of selection rules between the speed ratio of compression speed and shear rate, frequency ratio and angle of convergence, and assigning the calculated velocity ratio to 0 the spatial coordinates of the mixing zone.
- 19The method according to claim 19. El método de conformidad con la reivindicación 18, caracterizado porque comprende además repetir la asignación de la relación de velocidad calculada a la coordenada espacial de la zona de mezclado para una gama de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, el ángulo de azimut de la primera señal acústica, el ángulo de azimut de la segunda señal acústica, el ángulo de elevación de la primera señal acústica, o el ángulo de 18, characterized in that it further comprises repeating the assignment of the calculated speed ratio to the spatial coordinate of the mixing zone for a range of values of the position of the first acoustic source, the position of the second acoustic source, the position of the receiver , the azimuth angle of the first acoustic signal, the azimuth angle of the second acoustic signal, the elevation angle of the first acoustic signal, or the angle of IOS IOS IMPI IMPI INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL elevación de la segunda señal acústica, o cualquier combinación de dos o más de los mismos, para obtener el valor de la relación de velocidad para un volumen de la formación de roca alrededor del barreno. INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL elevation of the second acoustic signal, or any combination of two or more of them, to obtain the value of the speed ratio for a volume of rock formation around the hole.
- 20Un método para generar una imagen tridimensional de las propiedades no lineales de una formación de roca, caracterizado porque comprende:twenty. A method of generating a three-dimensional image of the nonlinear properties of a rock formation, characterized in that it comprises: leer, por un procesador, parámetros de medición que incluyan una posición de una primera fuente acústica configurada para generar una primera señal acústica a una primera frecuencia, una posición de una segunda fuente acústica configurada para generar una segunda señal acústica a una segunda frecuencia, una posición de un receptor configurado para recibir una señal detectada que regrese a un barreno desde una zona de mezcla dentro de la formación de roca en la intersección de la primera señal acústica y la segunda señal acústica, y ángulos de elevación y azimut de la primera y segunda señales acústicas;reading, by a processor, measurement parameters including a position of a first acoustic source configured to generate a first acoustic signal at a first frequency, a position of a second acoustic source configured to generate a second acoustic signal at a second frequency, a position of a receiver configured to receive a detected signal returning to a hole from a mixing zone within the rock formation at the intersection of the first acoustic signal and the second acoustic signal, and elevation and azimuth angles of the first and second acoustic signals;leer, por el procesador, una señal correlacionada M (t, δ, d) , que sea una función de tiempo de llegada t, diferencia de tiempo de inicio δ y relación de frecuencia d entre la primera frecuencia y la segunda frecuencia, la señal correlacionada M (t, Ó, d) contiene señales generadas por un proceso de mezcla no lineal a partir de una primera señal acústica y una segunda señal acústica en una zona de mezcla read, by the processor, a correlated signal M (t, δ, d), which is a function of arrival time t, start time difference δ and frequency relationship d between the first frequency and the second frequency, the signal correlated M (t, Ó, d) contains signals generated by a non-linear mixing process from a first acoustic signal and a second acoustic signal in a mixing zone 107 107 ΙΜΡΙ dentro de la formación de roca;ΙΜΡΙ within the rock formation;leer, por el procesador, un modelo de velocidad de compresión y cizallamiento de propagación inicial;read, by the processor, an initial propagation shear and compression rate model;calcular, por el procesador, un primer tiempo de viaje de la primera señal acústica de la primera fuente acústica a un centro de la zona de mezcla;calculating, by the processor, a first travel time of the first acoustic signal from the first acoustic source to a center of the mixing zone;calcular, por el procesador, un segundo tiempo de viaje de la segunda señal acústica de la segunda fuente acústica al centro de la zona de mezcla;calculating, by the processor, a second travel time of the second acoustic signal from the second acoustic source to the center of the mixing zone;calcular, por el procesador, un tercer tiempo de viaje entre el centro de la zona de mezcla y el receptor configurado para recibir la señal detectada que regrese al barreno que tenga una frecuencia igual a una diferencia entre la primera frecuencia y la segunda frecuencia, la señal detectada siendo generada por un proceso de mezcla no lineal de la primera señal acústica y la segunda señal acústica en la zona de mezcla;calculating, by the processor, a third travel time between the center of the mixing zone and the receiver configured to receive the detected signal that returns to the hole that has a frequency equal to a difference between the first frequency and the second frequency, the detected signal being generated by a non-linear mixing process of the first acoustic signal and the second acoustic signal in the mixing zone;calcular, por el procesador, un tiempo de llegada Tp correspondiente a un tiempo total de viaje de una señal que regrese al barreno mediante la adición del primera tiempo de viaje y el tercer tiempo de viaje, y calcular una diferencia de tiempo de tiempo de inicio δρ entre el primer tiempo de viaje y el segundo tiempo de viaje;calculating, by the processor, an arrival time Tp corresponding to a total travel time of a signal returning to the hole by adding the first travel time and the third travel time, and calculating a time difference from start time δρ between the first travel time and the second travel time;buscar todos los valores de tiempo de llegada t, diferencia de tiempo de tiempo de inicio δ, y la relación de look up all the arrival time values t, start time time difference δ, and the ratio of 108 108 IMPI IMPI INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL frecuencia d en la señal correlacionada M (t) '8·,' d) para determinar para que el valor de llegada Tnl, diferencia de tiempo de inicio 5nl y relación de frecuencia dm se produce una señal pico de banda limitada M (Tnl, Ónl, dNL) generada por el proceso de mezcla no lineal;y calcular, por el procesador, las trayectorias de propagación acústica usando un ángulo de elevación de la primera señal acústica, y una posición de la primera fuente acústica, y un ángulo de elevación de la segunda señal acústica, y una posición de la segunda fuente acústica con base en el modelo de velocidad de compresión y cizallamiento de propagación;MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY frequency d in the correlated signal M (t) '8 ·,' d) to determine so that the arrival value Tnl, start time difference 5nl and frequency ratio dm produces a peak signal of limited band M (Tnl, Ónl, dNL) generated by the non-linear mixing process;and calculating, by the processor, the acoustic propagation paths using an elevation angle of the first acoustic signal, and a position of the first acoustic source, and an elevation angle of the second acoustic signal, and a position of the second acoustic source acoustics based on the compression speed and propagation shear model;asignar la señal pico de banda limitada M (Tnl, 6nl, dm) generada por el proceso de mezcla no lineal a las coordenadas espaciales de una zona de mezcla de interacción donde se crucen la primera señal acústica y la segunda señal acústica;y repetir la asignación de la señal pico de banda limitada M (Tnl, Ónl, dui,) a las coordenadas espaciales de la zona de mezcla de interacción para una pluralidad de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, un ángulo de elevación de la primera señal acústica, un ángulo de azimut de la primera señal acústica, un ángulo de elevación de la segunda señal acústica, o un ángulo de azimut assigning the limited band peak signal M (Tnl, 6nl, dm) generated by the non-linear mixing process to the spatial coordinates of an interaction mixing zone where the first acoustic signal and the second acoustic signal intersect;and repeating the assignment of the limited band peak signal M (Tnl, Ónl, dui,) to the spatial coordinates of the interaction mixing zone for a plurality of values of the position of the first acoustic source, the position of the second acoustic source, the position of the receiver, an elevation angle of the first acoustic signal, an azimuth angle of the first acoustic signal, an elevation angle of the second acoustic signal, or an azimuth angle IMPI IMPI INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL cualquier combinación de dos generación de una imagen MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY any combination of two generation of an image Droceso de mezcla no lineal. Nonlinear mixing drug. 109 of the second acoustic signal, or more of them, and the three-dimensional of a force of the 109 de la segunda señal acústica, o o más de los mismos, y la tridimensional de una fuerza del
- 21El método de conformidad con la reivindicación twenty-one. The method according to claim 20, caracterizado porque comprende además la determinación de una ubicación de la zona de mezcla donde la primera señal acústica y la segunda señal acústica se cruzan usando la posición de la primera fuente acústica, el ángulo de elevación y el ángulo de azimut de la primera señal acústica y el posición de la segunda fuente acústica, el ángulo de elevación y el ángulo de azimut de la segunda señal acústica. 20, characterized in that it further comprises determining a location of the mixing zone where the first acoustic signal and the second acoustic signal intersect using the position of the first acoustic source, the elevation angle and the azimuth angle of the first signal acoustic and the position of the second acoustic source, the elevation angle and the azimuth angle of the second acoustic signal.
- 22A method of generating a three-dimensional image of a propagation compression rate, a shear rate spread, a ratio of the compression rate to the shear rate of a rock formation, or any combination of two or more of the same , characterized in that it comprises:22. Un método para generar una imagen tridimensional de una velocidad de compresión de propagación, una propagación de velocidad de cizallamiento, una relación de la velocidad de compresión a la velocidad de cizallamiento de una formación de roca, o cualquier combinación de dos o más de los mismos, caracterizado porque comprende: leer, por un procesador, parámetros de medición que incluyan una ubicación de una primera fuente acústica configurada para generar una primera señal acústica a una primera frecuencia, una posición de una segunda fuente acústica configurada para generar una segunda señal acústica a una segunda frecuencia, una posición de un receptor configurado para recibir una señal detectada que regrese a un barreno desde una zona de mezcla dentro de la formación de reading, by a processor, measurement parameters including a location of a first acoustic source configured to generate a first acoustic signal at a first frequency, a position of a second acoustic source configured to generate a second acoustic signal at a second frequency, a position of a receiver configured to receive a detected signal that returns to a hole from a mixing zone within the formation of 110 110 IMPI IMPI INSTITUTO MEXICANO , . . „ . ~ QE la RROPIEDAD roca en la intersección de la primera señal acustrü?©a,‘ALy segunda señal acústica, y ángulos de elevacióra-y'aDimut de la primera y segunda señales acústicas;MEXICAN INSTITUTE,. . „. ~ QE RROPIEDAD rock at the intersection of the first sign acustrü? © a,'ALy second acoustic signal, and elevation-y'aDimut angles of the first and second acoustic signals;leer, por el procesador, una señal correlacionada M (t, δ, d) , que sea una función de tiempo de llegada t, diferencia de tiempo de tiempo de inicio δ y relación de frecuencia d entre la primera frecuencia y la segunda frecuencia , la señal correlacionada M (t, δ, d) contiene señales generadas por un proceso de mezcla no lineal a partir de una primera señal acústica y una segunda señal acústica en una zona de mezcla dentro de la formación de roca;read, by the processor, a correlated signal M (t, δ, d), which is a function of arrival time t, time difference of start time δ and frequency relation d between the first frequency and the second frequency, the correlated signal M (t, δ, d) contains signals generated by a non-linear mixing process from a first acoustic signal and a second acoustic signal in a mixing zone within the rock formation;leer, por el procesador, un modelo de velocidad de compresión y cizallamiento de propagación inicial;read, by the processor, an initial propagation shear and compression rate model;estimar, por el procesador, un modelo de velocidad de propagación inicial usando registros de pozos en un barreno y suposiciones acerca de la continuidad lateral de la formación de roca lejos del barreno;estimating, by the processor, an initial propagation velocity model using well logs in a hole and assumptions about the lateral continuity of the rock formation away from the hole;calcular, por el procesador, un primer tiempo de viaje de la primera señal acústica de la primera fuente acústica a un centro de la zona de mezcla;calculating, by the processor, a first travel time of the first acoustic signal from the first acoustic source to a center of the mixing zone;calcular, por el procesador, un segundo tiempo de viaje de la segunda señal acústica de la segunda fuente acústica al centro de la zona de mezcla;calculating, by the processor, a second travel time of the second acoustic signal from the second acoustic source to the center of the mixing zone;calcular, por el procesador, un tercer tiempo de viaje entre el centro de la zona de mezcla y el receptor calculate, by the processor, a third travel time between the center of the mixing zone and the receiver 111 111 IMPI configurado para recibir la señal detectada qua·.regresa al barreno que tenga una frecuencia igual a una diferencia entre la primera frecuencia y la segunda frecuencia, la señal detectada siendo generada por un proceso de mezcla no lineal de la primera señal acústica y la segunda señal acústica en la zona de mezcla;IMPI configured to receive the detected signal qua ·. Returns to the hole that has a frequency equal to a difference between the first frequency and the second frequency, the detected signal being generated by a non-linear mixing process of the first acoustic signal and the second acoustic signal in the mixing area;calcular, por el procesador, un tiempo de llegada Tp correspondiente a un tiempo total de viaje de una señal que regrese al barreno mediante la adición del primera tiempo de viaje y el tercer tiempo de viaje, y calcular una diferencia de tiempo de tiempo de inicio δρ entre el primer tiempo de viaje y el segundo tiempo de viaje;calculating, by the processor, an arrival time Tp corresponding to a total travel time of a signal returning to the hole by adding the first travel time and the third travel time, and calculating a time difference from start time δρ between the first travel time and the second travel time;buscar todos los valores de tiempo de llegada t, diferencia de tiempo de tiempo de inicio δ, y la relación de frecuencia d en la señal correlacionada M (t, δ, d) para determinar para qué el valor de llegada Tnl, diferencia de tiempo de inicio 6nl y relación de frecuencia dNL se produce una señal pico de banda limitada M (Tnl, 6nl, dNL) generada por el proceso de mezcla no lineal;look up all the arrival time values t, start time time difference δ, and the frequency relationship d in the correlated signal M (t, δ, d) to determine why the arrival value Tnl, time difference At the 6nl start and dNL frequency ratio, a limited band peak signal M (Tnl, 6nl, dNL) is generated by the non-linear mixing process;comparar el tiempo de llegada Tp calculado con un compare the calculated arrival time Tp with a I measured arrival time TNL or compare the calculated start time time difference δρ with a measured start time difference Ónl;I tiempo de llegada medido TNL o comparar la diferencia de tiempo de tiempo de inicio δρ calculada con una diferencia de tiempo de inicio medida Ónl;actualizar el modelo de velocidad de propagación por inversión de velocidad tomográfica o inversión de forma update the propagation velocity model by tomographic velocity inversion or inversion of form 112 full-wave using a difference between measured and calculated arrival times if the calculated arrival time is different from the measured arrival time, or using a difference between the calculated and measured start time differences if the calculated start time difference it is different from the measured start time difference, or both;112 de onda completa usando una diferencia entre los tiempos de llegada medidos y calculados si el tiempo de llegada calculado es diferente del tiempo de llegada medido, o usar una diferencia entre las diferencias de tiempo de inicio calculada y medida si la diferencia de tiempo de inicio calculada es diferente de la diferencia de tiempo de inicio medida, o ambas;iteratively repeat the above steps until the calculated arrival time is substantially equal to a measured arrival time, or the calculated starting time difference is substantially equal to the measured starting time difference, or both, for a range of values the position of the first acoustic source, the position of the second acoustic source, the position of the receiver, the azimuth angle of the first acoustic signal, the azimuth angle of the second acoustic signal, the elevation angle of the first acoustic signal, or the elevation angle of the second acoustic signal, or any combination of two or more thereof, to obtain a propagation velocity Vp and propagation velocity Vs that results in the calculated arrival time being substantially equal to the measured arrival time or the calculated time difference being substantially equal to the measured starting time difference, or both;and generate a three-dimensional image of a speed repetir iterativamente los pasos anteriores hasta que el tiempo de llegada calculada sea sustancialmente igual a un tiempo de llegada medida, o la diferencia de tiempo de inicio calculada sea sustancialmente igual a la diferencia de tiempo de inicio medida, o ambas, para un intervalo de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, el ángulo de azimut de la primera señal acústica, el ángulo de azimut de la segunda señal acústica, el ángulo de elevación de la primera señal acústica, o el ángulo de elevación de la segunda señal acústica, o cualquier combinación de dos o más de los mismos, para obtener una velocidad de propagación Vp y velocidad de propagación Vs que resulten en que el tiempo de llegada calculado sea sustancialmente igual a el tiempo de llegada medida o la diferencia de tiempo calculada sea sustancialmente igual a la diferencia de tiempo de inicio medida, o ambas;y generar una imagen tridimensional de una velocidad 113 113 IMPI compression spread, a shear rate spread, a ratio of the compression rate to the shear rate, or any combination of two or more thereof. IMPI de compresión de propagación, una propagación de la velocidad de cizallamiento, una relación de la velocidad de compresión a la velocidad de cizallamiento, o cualquier combinación de dos o más de las mismas.
- 232. 3. The method according to claim 23. El método de conformidad con la reivindicación 22, caracterizado porque comprende además determinar un valor de la velocidad de compresión de propagación, un valor de la velocidad de cizallamiento de propagación, o un valor de la relación de velocidad de la velocidad de compresión y la velocidad de cizallamiento, o cualquier combinación de dos o más de los mismos. 22, characterized in that it further comprises determining a value of the propagation compression rate, a value of the propagation shear rate, or a value of the speed ratio of the compression rate and the shear rate, or any combination of two or more of them.
- 24The method according to claim 24. El método de conformidad con la reivindicación 22, caracterizado porque comprende además calcular las coordenadas espaciales de la zona de mezcla donde las dos señales acústicas se cruzan, calcular un ángulo de convergencia entre la primera señal acústica proveniente de la primera fuente acústica y la segunda señal acústica proveniente de la segunda fuente acústica con base en el ángulo de elevación y el ángulo de azimut de la primera señal acústica, y la posición de la primera fuente acústica, y el ángulo de elevación y el ángulo de azimut de la segunda señal acústica, y la posición de la segunda fuente acústica. 22, characterized in that it also comprises calculating the spatial coordinates of the mixing zone where the two acoustic signals intersect, calculating an angle of convergence between the first acoustic signal from the first acoustic source and the second acoustic signal from the second acoustic source based on the elevation angle and azimuth angle of the first acoustic signal, and the position of the first acoustic source, and the elevation angle and azimuth angle of the second acoustic signal, and the position of the second acoustic source.
- 25The method according to claim 25. El método de conformidad con la reivindicación 24, caracterizado porque comprende además calcular la relación de velocidad de la velocidad de compresión y la 24, characterized in that it further comprises calculating the speed ratio of the compression rate and the 114 shear rate in the mixing zone at the measured frequency ratio dNL and the convergence angle calculated using a ratio of selection rules between the compression ratio velocity ratio and the shear rate, the frequency ratio, and the convergence angle. 114 velocidad de cizallamiento en la zona de mezcla a parCll dela relación de frecuencia medida dNL y el ángulo de convergencia calculado usando una relación de reglas de selección entre la relación de velocidad de la velocidad de compresión y la velocidad de cizallamiento, la relación de frecuencia y el ángulo de convergencia.
- 26The method according to claim 26. El método de conformidad con la reivindicación 25, caracterizado porque comprende además repetir la asignación de la relación de velocidad calculada a la coordenada espacial de la zona de mezclado para una gama de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, el ángulo de azimut de la primera señal acústica, el ángulo de azimut de la segunda señal acústica, el ángulo de elevación de la primera señal acústica, o el ángulo de elevación de la segunda señal acústica, o cualquier combinación de dos o más de los mismos para obtener una tridimensional imagen de la relación de velocidad. 25, characterized in that it further comprises repeating the assignment of the calculated speed ratio to the spatial coordinate of the mixing zone for a range of values of the position of the first sound source, the position of the second sound source, the position of the receiver , the azimuth angle of the first acoustic signal, the azimuth angle of the second acoustic signal, the elevation angle of the first acoustic signal, or the elevation angle of the second acoustic signal, or any combination of two or more of them to obtain a three-dimensional image of the speed ratio.
- 27A system to generate a three-dimensional image of a rock formation, characterized in that it comprises:27. Un sistema para generar una imagen tridimensional de una formación de roca, caracterizado porque comprende: a first acoustic source configured to generate a first acoustic signal, wherein the first acoustic signal comprises a first plurality of pulses arranged in a time sequence, the first plurality una primera fuente acústica configurada para generar una primera señal acústica, en donde la primera señal acústica comprende una primera pluralidad de pulsos dispuestos en una secuencia de tiempo, la primera pluralidad 115 of pulses being separated in time, each pulse comprises a first signal modulated at a central frequency, where the central frequencies of two consecutive pulses are different;115 de pulsos siendo separados en el tiempo, cada pulso comprende una primera señal modulada a una frecuencia central, en donde las frecuencias centrales de dos pulsos consecutivos son diferentes;a second acoustic source configured to generate a second acoustic signal by a second acoustic source, wherein the second acoustic signal comprises a second plurality of pulses arranged as a time sequence, the second plurality of pulses being separated in time, wherein a time spacing between the centers of two consecutive pulses is the same as a time spacing between the centers of two corresponding pulses in the first plurality of pulses, wherein a start time difference is provided between a start time of a transmission of the second plurality of pulses and a start time of a transmission of the first plurality of pulses, wherein each pulse comprises a modulated signal, and wherein a center frequency of the modulated signal within each pulse in the second plurality of pulses is a selected fraction of the center frequency of the modulated signal within each corresponding pulse in the first plurality of pulses;una segunda fuente acústica configurada para generar una segunda señal acústica por una segunda fuente acústica, en donde la segunda señal acústica comprende una segunda pluralidad de pulsos dispuestos como una secuencia de tiempo, la segunda pluralidad de pulsos siendo separados en el tiempo, en donde una separación en tiempo entre los centros de dos pulsos consecutivos es la misma que una separación en tiempo entre los centros de dos pulsos correspondientes en la primera pluralidad de pulsos, en donde una diferencia de tiempo de inicio se proporciona entre un tiempo de inicio de una transmisión de la segunda pluralidad de pulsos y un tiempo de inicio de una transmisión de la primera pluralidad de pulsos, en donde cada pulso comprende una señal modulada, y en donde una frecuencia central de la señal modulada dentro de cada pulso en la segunda pluralidad de pulsos es una fracción seleccionada de la frecuencia central de la señal modulada dentro de cada pulso correspondiente en la primera pluralidad de pulsos;en donde la primera fuente acústica y la segunda fuente acústica están dispuestas dentro del barreno y son controlables de tal manera que las trayectorias de la primera wherein the first sound source and the second sound source are arranged within the hole and are controllable in such a way that the trajectories of the first 116 116 ΙΜΡϊ ΙΜΡϊ INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL y segunda señales de las acústicas se crucen en un volumen de intersección fuera del barreno;MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY and second acoustic signals intersect in an intersecting volume outside the hole;a receiver arranged within the hole, the receiver is configured to detect a received signal that returns to the hole, the received signal includes a signal that is generated by a non-linear mixing process from the first acoustic signal and the second acoustic signal in a nonlinear mixing zone within the intersecting volume;un receptor dispuesto dentro del barreno, el receptor está configurado para detectar una señal recibida que regrese al barreno, la señal recibida incluye una señal que se genera por un proceso de mezcla no lineal a partir de la primera señal acústica y la segunda señal acústica en una zona de mezcla no lineal dentro del volumen de intersección;a first processor configured to perform data processing on the received signal to extract the signal generated by the non-linear mixing process on noise or on signals generated by a linear interaction process, or both;and a second processor configured to generate a three-dimensional image of a propagation compression rate, a shear rate propagation, a ratio of the compression rate and the shear rate, or nonlinear properties of a rock formation, or any combination of two or more of them based on the signal generated by the non-linear mixing process. un primer procesador configurado para llevar a cabo procesamiento de datos en la señal recibida para extraer la señal generada por el proceso de mezcla no lineal sobre ruido o sobre señales generadas por un proceso de interacción lineal, o ambos;y un segundo procesador configurado para generar una imagen tridimensional de una velocidad de compresión de propagación, una propagación de velocidad de cizallamiento, una relación de la velocidad de compresión y la velocidad de cizallamiento, o propiedades no lineales de una formación de roca, o cualquier combinación de dos o más de las mismas con base en la señal generada por el proceso de mezcla no lineal.
- 31The system in accordance with 31. El sistema de conformidad con la 20 reivindicación 27, caracterizado porque el segundo procesador está configurado para:twenty Claim 27, characterized in that the second processor is configured to: estimar un modelo de velocidad de propagación inicial usando registros de pozos en un barreno y suposiciones acerca de la continuidad lateral de una estimate an initial propagation velocity model using well logs in a hole and assumptions about the lateral continuity of a 25 rock formation away from the hole;25 formación de roca lejos del barreno;118 calculate a first travel-rte time — Gives first acoustic signal from the first acoustic source to a center of the mixing zone;118 calcular un primer tiempo de viajer-rte—Da primera señal acústica de la primera fuente acústica a un centro de la zona de mezcla;calcular un segundo tiempo de viaje de la segunda señal acústica de la segunda fuente acústica al centro de la zona de mezcla;calculating a second travel time of the second acoustic signal from the second acoustic source to the center of the mixing zone;calcular un tercer tiempo de viaje entre el centro de la zona de mezcla y un receptor configurado para recibir una señal detectada que regrese al barreno que tenga una frecuencia igual a una diferencia entre la primera frecuencia y la segunda frecuencia, la señal detectada siendo generada por un proceso de mezcla no lineal a partir de la primera señal acústica y la segunda señal acústica en la zona de mezcla;calculating a third travel time between the center of the mixing zone and a receiver configured to receive a detected signal that returns to the hole that has a frequency equal to a difference between the first frequency and the second frequency, the detected signal being generated by a non-linear mixing process from the first acoustic signal and the second acoustic signal in the mixing zone;calcular un tiempo de llegada Tp correspondiente a un tiempo total de viaje de una señal que regrese al barreno mediante la adición del primer tiempo de viaje y el tercer tiempo de viaje, y el cálculo de una diferencia de tiempo de inicio δρ entre el primer tiempo de viaje y el segundo tiempo de viaje;calculating an arrival time Tp corresponding to a total travel time of a signal returning to the hole by adding the first travel time and the third travel time, and calculating a start time difference δρ between the first time travel and the second travel time;extracting from the signal received at the receiver, the signals generated by the non-linear mixing process to produce for each start time difference δ and for each frequency relationship d, a correlated signal M (t, δ, d), which is a function of arrival time t, the extraer de la señal recibida en el receptor, las señales generadas por el proceso de mezcla no lineal para producir para cada diferencia de tiempo de inicio δ y para cada relación de frecuencia d, una señal correlacionada M (t, δ, d) , que es una función del tiempo de llegada t, la 119 difference in start time δ and the relative rate, frequency d, and that contains the non-linear interaction signals;119 diferencia de tiempo de inicio δ y la relacj.óji_de , frecuencia d, y que contiene las señales de interacción no lineales;buscar todos los valores de tiempo de llegada t, diferencia de tiempo de inicio δ, y relación de frecuencia d en la señal correlacionada M (t, δ, d) para determinar un valor de tiempo de llegada TNL, diferencia de tiempo de inicio 6nl y relación de frecuencia dNL durante la cual se produce una señal pico de banda limitada generada por el proceso de mezcla no lineal;look up all the arrival time values t, start time difference δ, and frequency ratio d in the correlated signal M (t, δ, d) to determine a time of arrival value TNL, start time difference 6nl and dNL frequency ratio during which a limited band peak signal produced by the non-linear mixing process is produced;comparar el tiempo de llegada Tp calculado con un tiempo de llegada medido TNL y comparar la diferencia de tiempo de inicio calculada δρ con una diferencia de tiempo de inicio medida Ónl;compare the calculated arrival time Tp with a measured arrival time TNL and compare the calculated start time difference δρ with a measured start time difference Ónl;determinar si el tiempo de llegada Tp calculado es diferente del tiempo de llegada TNL medido y la diferencia de tiempo de inicio δρ calculada es diferente de la diferencia de tiempo de inicio Ónl medida y, si es así, actualizar el modelo de velocidad de propagación usando una diferencia entre los tiempos de llegada medido y calculado y una diferencia entre las diferencias de tiempo de inicio calculadas y medidas;y repetir iterativamente los pasos anteriores hasta que el tiempo de llegada calculada correspondiente al tiempo total de viaje sea sustancialmente igual a un tiempo de llegada medida, o la diferencia de tiempo de inicio calculada determine if the calculated arrival time Tp is different from the measured TNL arrival time and the calculated start time difference δρ is different from the measured start time difference Ónl and, if so, update the propagation velocity model using a difference between measured and calculated arrival times and a difference between calculated and measured start time differences;and iteratively repeating the above steps until the calculated arrival time corresponding to the total travel time is substantially equal to a measured arrival time, or the calculated start time difference 120 120 ΙΜ Ρ is substantially equal to a difference ~ dtí L lempo — measured start, or both, for a range of values of the position of the first sound source, the position of the second sound source, the position of the receiver, the azimuth angle of the first acoustic signal, the azimuth angle of the second acoustic signal, the elevation angle of the first acoustic signal, or the elevation angle of the second acoustic signal, or any combination of two or more thereof, to obtain a propagation velocity Vp and a propagation velocity Vs that result in the calculated arrival time being substantially equal to the measured arrival time or the calculated time difference being substantially equal to the measured starting time difference, or both ;and generating a three-dimensional image of a propagation compression rate, a shear rate spread, a ratio of the compression rate to the shear rate, or nonlinear properties, or any combination of two or more thereof. ΙΜ Ρ sea sustancialmente igual a una diferencia~dtí L lempo—deinicio medida, o ambas, para un intervalo de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, el ángulo de azimut de la primera señal acústica, el ángulo de azimut de la segunda señal acústica, el ángulo de elevación de la primera señal acústica, o el ángulo de elevación de la segunda señal acústica, o cualquier combinación de dos o más de los mismos, para obtener una velocidad de propagación Vp y velocidad de propagación Vs que resulten en que el tiempo de llegada calculado sea sustancialmente igual a el tiempo de llegada medida o la diferencia de tiempo calculada sea sustancialmente igual a la diferencia de tiempo de inicio medida, o ambas;y generar una imagen tridimensional de una velocidad de compresión de propagación, una propagación de la velocidad de cizallamiento, una relación de la velocidad de compresión a la velocidad de cizallamiento, o propiedades no lineales, o cualquier combinación de dos o más de las mismas.
- 343. 4. The system in accordance with 34. El sistema de conformidad con la 122 122 IMPI claim 33, characterized in that the oagnndn processor is configured to determine a location of a mixing zone where the first acoustic signal and the second acoustic signal interact non-linearly based on the position of the first acoustic source, the elevation angle and the azimuth angle of the first acoustic signal and the position of the second acoustic source, the elevation angle and the azimuth angle of the second acoustic signal. IMPI reivindicación 33, caracterizado porque el oagnndn procesador está configurado para determinar una ubicación de una zona de mezcla donde la primera señal acústica y la segunda señal acústica ínteractúan de forma no lineal con base en la posición de la primera fuente acústica, el ángulo de elevación y el ángulo de azimut de la primera señal acústica y la posición de la segunda fuente acústica, el ángulo de elevación y el ángulo de azimut de la segunda señal acústica.
- 45Un sistema para generar una imagen tridimensional de las propiedades no lineales de una formación de roca, caracterizado porque comprende un procesador configurado para:Four. Five. A system to generate a three-dimensional image of the non-linear properties of a rock formation, characterized in that it comprises a processor configured to: leer parámetros de medición que incluyan una posición de una primera fuente acústica configurada para generar una primera señal acústica a una primera frecuencia, una posición de una segunda fuente acústica configurada para generar una segunda señal acústica a una segunda frecuencia, read measurement parameters including a position of a first acoustic source configured to generate a first acoustic signal at a first frequency, a position of a second acoustic source configured to generate a second acoustic signal at a second frequency, elevation and azimuth angles of the first and second acoustic signals;ángulos de elevación y azimut de la primera y segunda señales acústicas;leer una señal correlacionada M (t, 8, d) , que sea una función de tiempo de llegada t, diferencia de tiempo de inicio δ y relación de frecuencia d entre la primera frecuencia y la segunda frecuencia, la señal correlacionada M (t, δ, d) contiene señales generadas por un proceso de mezcla read a correlated signal M (t, 8, d), which is a function of arrival time t, start time difference δ and frequency relationship d between the first frequency and the second frequency, the correlated signal M (t, δ, d) contains signals generated by a mixing process 130 130 IMPI IMPI INSTITUTO MEXICANO DE I.a PROPIEDAD industrial no lineal a partir de una primera serial aóÜyLica—y—-una. segunda señal acústica en una zona de mezcla dentro de la formación de roca;MEXICAN INSTITUTE OF NON-LINEAR INDUSTRIAL PROPERTY from a first serial aóÜyLica — and —- una. second acoustic signal in a mixing zone within the rock formation;leer un modelo de velocidad de compresión y cizallamiento de propagación inicial;read a model of compression speed and initial propagation shear;calcular un primer tiempo de viaje de la primera señal acústica de la primera fuente acústica a un centro de la zona de mezcla;calculating a first travel time of the first acoustic signal from the first acoustic source to a center of the mixing zone;calcular un segundo tiempo de viaje de la segunda señal acústica de la segunda fuente acústica al centro de la zona de mezcla;calculating a second travel time of the second acoustic signal from the second acoustic source to the center of the mixing zone;calcular un tercer tiempo de viaje entre el centro de la zona de mezcla y el receptor configurado para recibir la señal detectada que regrese al barreno que tenga una frecuencia igual a una diferencia entre la primera frecuencia y la segunda frecuencia, la señal detectada siendo generada por un proceso de mezcla no lineal de la primera señal acústica y la segunda señal acústica en la zona de mezcla;calculate a third travel time between the center of the mixing zone and the receiver configured to receive the detected signal that returns to the hole that has a frequency equal to a difference between the first frequency and the second frequency, the detected signal being generated by a non-linear mixing process of the first acoustic signal and the second acoustic signal in the mixing zone;calcular un tiempo de llegada Tp correspondiente a un tiempo total de viaje de una señal que regrese al barreno mediante la adición del primera tiempo de viaje y el tercer tiempo de viaje, y calcular una diferencia de tiempo de tiempo de inicio δρ entre el primer tiempo de viaje y el segundo tiempo de viaje;calculating an arrival time Tp corresponding to a total travel time of a signal returning to the hole by adding the first travel time and the third travel time, and calculating a start time time difference δρ between the first time travel and the second travel time;buscar todos los valores de tiempo de llegada t, find all arrival time values t, IMPI IMPI INSTITUTO MEXICANO DE LA «OPISÜAÜ INDUSTRIAL diferencia de tiempo de tiempo de inicio δ, y la relación de frecuencia d en la señal correlacionada M (t, δ, d) para determinar para que el valor de llegada TNL, diferencia de tiempo de inicio 6m y relación de frecuencia dm se produce una señal pico de banda limitada M (Tnl, 6nl, dm) generada por el proceso de mezcla no lineal;y calcular las trayectorias de propagación acústica usando un ángulo de elevación de la primera señal acústica, y una posición de la primera fuente acústica, y un ángulo de elevación de la segunda señal acústica, y una posición de la segunda fuente acústica con base en el modelo de velocidad de compresión y cizallamiento de propagación;INSTITUTO MEXICANO DE LA «OPISÜAÜ INDUSTRIAL time difference of start time δ, and the frequency relation d in the correlated signal M (t, δ, d) to determine so that the arrival value TNL, start time difference 6m and frequency ratio dm produces a limited band peak signal M (Tnl, 6nl, dm) generated by the non-linear mixing process;and calculating the acoustic propagation paths using an elevation angle of the first acoustic signal, and a position of the first acoustic source, and an elevation angle of the second acoustic signal, and a position of the second acoustic source based on the compression rate and propagation shear model;asignar la señal pico de banda limitada M (Tnl, 6nl, dm) generada por el proceso de mezcla no lineal a las coordenadas espaciales de una zona de mezcla de interacción donde se crucen la primera señal acústica y la segunda señal acústica;y repetir la asignación de la señal pico de banda limitada M (Tm, διη., dm) a las coordenadas espaciales de la zona de mezcla de interacción para una pluralidad de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, un ángulo de elevación de la primera señal acústica, un ángulo de azimut de la primera señal acústica, un ángulo de elevación de la segunda señal acústica, o un ángulo de azimut assigning the limited band peak signal M (Tnl, 6nl, dm) generated by the non-linear mixing process to the spatial coordinates of an interaction mixing zone where the first acoustic signal and the second acoustic signal intersect;and repeating the assignment of the limited band peak signal M (Tm, διη., dm) to the spatial coordinates of the interaction mixing zone for a plurality of values of the position of the first acoustic source, the position of the second acoustic source, the position of the receiver, an elevation angle of the first acoustic signal, an azimuth angle of the first acoustic signal, an elevation angle of the second acoustic signal, or an azimuth angle 132 two 132 dos ΙΜΡϊ ΙΜΡϊ INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL de la segunda señal acústica, o cualquier combinación de o más de los mismos, y la generación de una imagen tridimensional de una fuerza del proceso de mezcla no lineal. MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY of the second acoustic signal, or any combination of or more thereof, and the generation of a three-dimensional image of a force of the non-linear mixing process.
- 47A system for generating a three-dimensional image of a propagation compression rate, a shear rate spread, a ratio of the compression rate to the shear rate of a rock formation, or any combination of two or more of the , characterized in that it comprises a processor configured to:47. Un sistema para generar una imagen tridimensional de una velocidad de compresión de propagación, una propagación de la velocidad de cizallamiento, una relación de la velocidad de compresión a la velocidad de cizallamiento de una formación de roca, o cualquier combinación de dos o más de las mismas, caracterizado porque comprende un procesador configurado para: leer parámetros de medición que incluyan una ubicación de una primera fuente acústica configurada para generar una primera señal acústica a una primera frecuencia, una posición de una secunda fuente acústica configurada para generar una segunda señal acústica a una segunda frecuencia, una posición de un receptor configurado para recibir una read measurement parameters that include a location of a first acoustic source configured to generate a first acoustic signal at a first frequency, a position of a second acoustic source configured to generate a second acoustic signal at a second frequency, a position of a configured receiver to receive a 133 133 IMPI IMPI INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL señal detectada que regrese a un barreno desde una znna. .de. MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY detected signal returning to a hole from a znna. .of. mezcla dentro de la formación de roca en la intersección de la primera señal acústica y la segunda señal acústica, y ángulos de elevación y azimut de la primera y segunda señales acústicas;mix within the rock formation at the intersection of the first acoustic signal and the second acoustic signal, and elevation and azimuth angles of the first and second acoustic signals;leer una señal correlacionada M (t, δ, d) , que sea una función de tiempo de llegada t, diferencia de tiempo de tiempo de inicio δ y relación de frecuencia d entre la primera frecuencia y la segunda frecuencia, la señal correlacionada M (t, δ, d) contiene señales generadas por un proceso de mezcla no lineal a partir de una primera señal acústica y una segunda señal acústica en una zona de mezcla dentro de la formación de roca;read a correlated signal M (t, δ, d), which is a function of arrival time t, start time time difference δ and frequency relationship d between the first frequency and the second frequency, the correlated signal M ( t, δ, d) contains signals generated by a non-linear mixing process from a first acoustic signal and a second acoustic signal in a mixing zone within the rock formation;leer un modelo de velocidad de compresión y cizallamiento de propagación inicial;read a model of compression speed and initial propagation shear;estimar un modelo de velocidad de propagación inicial usando registros de pozos en un barreno y suposiciones acerca de la continuidad lateral de la formación de roca lejos del barreno;estimate an initial propagation velocity model using well logs in a hole and assumptions about the lateral continuity of the rock formation away from the hole;calcular un primer tiempo de viaje de la primera señal acústica de la primera fuente acústica a un centro de la zona de mezcla;calculating a first travel time of the first acoustic signal from the first acoustic source to a center of the mixing zone;calcular un segundo tiempo de viaje de la segunda señal acústica de la segunda fuente acústica al centro de la zona de mezcla;calculating a second travel time of the second acoustic signal from the second acoustic source to the center of the mixing zone;134 134 IMPI IMPI INSTITUTO MtXICANí i Dt LA FROfltÜAC INDUSTRIAL calcular un tercer tiempo de vi a j e-entro ol—oai>too~~~, de la zona de mezcla y el receptor configurado para recibir la señal detectada que regrese al barreno que tenga una frecuencia igual a una diferencia entre la primera frecuencia y la segunda frecuencia, la señal detectada siendo generada por un proceso de mezcla no lineal de la primera señal acústica y la segunda señal acústica en la zona de mezcla;INSTITUTO MtXICANí i Dt LA FROfltÜAC INDUSTRIAL calculate a third time of vi aj e-entro ol — oai> too ~~~, of the mixing zone and the receiver configured to receive the detected signal that returns to the hole that has a frequency equal to a difference between the first frequency and the second frequency, the detected signal being generated by a non-linear mixing process of the first acoustic signal and the second acoustic signal in the mixing zone;calcular un tiempo de llegada Tp correspondiente a un tiempo total de viaje de una señal que regrese al barreno mediante la adición del primera tiempo de viaje y el tercer tiempo de viaje, y calcular una diferencia de tiempo de tiempo de inicio δρ entre el primer tiempo de viaje y el segundo tiempo de viaje;calculating an arrival time Tp corresponding to a total travel time of a signal returning to the hole by adding the first travel time and the third travel time, and calculating a start time time difference δρ between the first time travel and the second travel time;buscar todos los valores de tiempo de llegada t, diferencia de tiempo de tiempo de inicio δ, y la relación de frecuencia d en la señal correlacionada M (t, δ, d) para determinar para que el valor de llegada TNL, diferencia de tiempo de inicio δΝΐ, y relación de frecuencia ónl se produce una señal pico de banda limitada M (Tnl, 6nl, dui,) generada por el proceso de mezcla no lineal;look up all the arrival time values t, start time time difference δ, and the frequency relationship d in the correlated signal M (t, δ, d) to determine so that the arrival value TNL, time difference starting δΝΐ, and frequency relation ónl produces a limited band peak signal M (Tnl, 6nl, dui,) generated by the non-linear mixing process;comparar el tiempo de llegada Tp calculado con un tiempo de llegada medido Tnl o comparar la diferencia de tiempo de tiempo de inicio δρ calculada con una diferencia de tiempo de inicio medida Ónl;compare the calculated arrival time Tp with a measured arrival time Tnl or compare the calculated start time time difference δρ with a measured start time difference Ónl;actualizar el modelo de velocidad de propagación update the propagation speed model 135 135 IMPI IMPI INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL por inversión de velocidad tomográfica o invc-uaiém—do forma de onda completa usando una diferencia entre la los tiempos de llegada medidos y calculados si el tiempo de llegada calculado es diferente del tiempo de llegada medido, o usar una diferencia entre las diferencias de tiempo de inicio calculada y medida si la diferencia de tiempo de inicio calculada es diferente de la diferencia de tiempo de inicio medida, o ambas;MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY by reversing tomographic speed or invincing a full waveform using a difference between the measured and calculated arrival times if the calculated arrival time is different from the measured arrival time, or using a difference between the measured and calculated start time differences if the calculated start time difference is different from the measured start time difference, or both;iteratively repeat the above steps until the calculated arrival time is substantially equal to a measured arrival time, or the calculated starting time difference is substantially equal to the measured starting time difference, or both, for a range of values the position of the first acoustic source, the position of the second acoustic source, the position of the receiver, the azimuth angle of the first acoustic signal, the azimuth angle of the second acoustic signal, the elevation angle of the first acoustic signal, or the elevation angle of the second acoustic signal, or any combination of two or more thereof, to obtain a propagation velocity Vp and propagation velocity Vs that results in the calculated arrival time being substantially equal to the measured arrival time or the calculated time difference being substantially equal to the measured starting time difference, or both;and repetir iterativamente los pasos anteriores hasta que el tiempo de llegada calculada sea sustancialmente igual a un tiempo de llegada medida, o la diferencia de tiempo de inicio calculada sea sustancialmente igual a la diferencia de tiempo de inicio medida, o ambas, para un intervalo de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, el ángulo de azimut de la primera señal acústica, el ángulo de azimut de la segunda señal acústica, el ángulo de elevación de la primera señal acústica, o el ángulo de elevación de la segunda señal acústica, o cualquier combinación de dos o más de los mismos, para obtener una velocidad de propagación Vp y velocidad de propagación Vs que resulten en que el tiempo de llegada calculado sea sustancialmente igual a el tiempo de llegada medida o la diferencia de tiempo calculada sea sustancialmente igual a la diferencia de tiempo de inicio medida, o ambas;y 136 136 IMPI IMPI INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL generar una imagen tridimensional de una velocidad”·”™· de compresión de propagación, una propagación de la velocidad de cizallamiento, una relación de la velocidad de compresión a la velocidad de cizallamiento, o cualquier combinación de dos o más de las mismas. MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY generate a three-dimensional image of a propagation compression speed “·” ™ ·, a propagation of shear rate, a ratio of compression rate to shear rate, or any combination of two or more of them.
- 51The method according to claim 51. El método de conformidad con la reivindicación 50, caracterizado porque comprende además repetir la asignación de la relación de velocidad calculada a la coordenada espacial de la zona de mezclado para una gama de valores de la posición de la primera fuente acústica, la posición de la segunda fuente acústica, la posición del receptor, el ángulo de azimut de la primera señal acústica, el ángulo de azimut de la segunda señal acústica, el ángulo de elevación de la primera señal acústica, o el ángulo de elevación de la segunda señal acústica, o cualquier combinación de dos o más de los mismos para obtener una imagen tridimensional de la relación de velocidad. 50, characterized in that it further comprises repeating the assignment of the calculated speed ratio to the spatial coordinate of the mixing zone for a range of values of the position of the first acoustic source, the position of the second acoustic source, the position of the receiver , the azimuth angle of the first acoustic signal, the azimuth angle of the second acoustic signal, the elevation angle of the first acoustic signal, or the elevation angle of the second acoustic signal, or any combination of two or more of them to obtain a three-dimensional image of the speed ratio. 138 138 INSTITUTO MEXICANO DE LA PROPIEDAD MEXICAN INSTITUTE OF PROPERTY INDUSTRIAL INDUSTRIAL
Independent claims32
468 paragraphs in 54 sections, as filed
(54) Title: SYSTEM AND METHOD FOR INVESTIGATING SUBSUPFICIAL CHARACTERISTICS OF A ROCK FORMATION.
(54) Title: SYSTEM AND METHOD FOR INVESTIGATING SUB-SURFACE FEATURES OF A ROCK FORMATION.
(57) Summary
A method and system for investigating rock formations outside a hole are provided. The method includes generating a first sound wave at a first frequency by a first sound source, and generating a second sound wave at a second frequency by a second sound source. The first and second acoustic sources are arranged within a localized area of the hole. The first and second sound waves intersect in an intersecting volume outside the hole. The method further includes receiving a third sound wave at a third frequency, the third shear sound wave returns to the hole due to a non-linear mixing process in a non-linear mixing zone within the intersection volume at a receiver arranged in the hole. The third frequency equals a difference between the first frequency and the second frequency.
(57) Abstract
A method and system for investigating rock formations outside a borehole are provided. The method ineludes generating a first acoustic wave at a first frequeney by a first acoustic source; and generating a second acoustic wave at a second frequeney by a second acoustic source. The first and the second acoustic sources are arranged within a localized area of the borehole. The first and the second acoustic waves intersect in an intersection volume outside the borehole. The method further ineludes receiving a third acoustic wave at a third frequeney, the third shear acoustic wave returning to the borehole due to a non-linear mixing process in a non-linear mixing zone within the intersection volume at a receiver arranged in the borehole. The third frequeney is equal to a difference between the first frequeney and the second frequeney.
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Institute
Mexican Property
Industrial Efl
<img file="MX338705B_D0001.tif" />
PATENT TITLE NO. 338705
Owner (s): CHEVRON USA INC .; LOS ALAMOS NATIONAL SECURITY LLC
Address: 6001 Bollinger Canyon Road, San Ramón, California, 94583, USA; Mail Stop A
187, Los Alamos, New Mexico, 87544, USA
Name: SYSTEM AND METHOD FOR INVESTIGATING SUBSUPFICIAL CHARACTERISTICS OF A ROCK FORMATION.
Classification: IC.8: G01V1 / 40
Inventors): CUNG KHAC VU; CHRISTOPHER H. SKELT; KURT T. ΝΙΗΘ; PAUL A.
JOHNSON; ROBERT TO GLTYER JAMES A. TEN CATE; PIERRE-YVES LE BAS;
Carene s. larmat
REQUEST
Number: International filing date:
MX / a / 2015/008273 November 9, 2011
Country:
US
Divisional Patent Number: 328413
PRIORITY Date:
November 2010
Number:
61/413,173
Validity: Twenty-years
Venchnienté Date: November 9, 2031 fca patent of seíotorga reference with the foundation in the articles 1 ° 2 ° fraction v, 6 ° fraction Id, and $ 9 of the Industrial Property Law.
In accordance with article 23 of I? IndusWaf Property Law, I patent patent has a validity of twenty irrevocable years, counted from the date of filing of the application inteimmonel f eatart aafelB to the patK 'of t he rate to keep the rights alive. '· ·' Ij
MlBNMMMMeM ^ MMamt titulo lo NiWMMMMMMto en to <ítopu «to pork» anísciteas ** raeelene »llt and 7” bis 2 of the Industrial Property Law (Official Gazette of the Federation (DOF) 06/27/1991, amended on 02/08/08 / 1994, 10/25/1996, 12/26/1997, 05/17/1999, 01/26/2004, 06/16/2005, 01/25/2006, 06/05/2009, 06/06/01 / 2010, 06/18/2010, 06/28/2010, 01/27/2012 and 09/04/2012); Articles 1, 3rd fraction V Clause a), 4th and 12th fractions I and lll of the Regulations of the Mexican Institute of Industrial Property (DOF 12/14/1999, amended on 07/01/2002, 07/15/2004, 07/28/2004 and 07/09/2007); Articles 1, 3, 4, 5, section V, subsection a), 16 sections l and lll and 30 of the Organic Statute of the Mexican Institute of Industrial Property (DOF) 12/27/1999, amended on 10/10/2002, 07/29/2004, 04/08/2004 and 09/13/2007); 1, 3 and 5 subsection a) of the Agreement that delegates powers to the Deputy Directors General, Coordinator, Divisional Direc tors, Holders of the Regional Offices, Divisional Deputy Directors, Departmental Coordinators and other subordinates of the Mexican Institute of Industrial Property. (DOF 12/15/1999, amended on 02/04/2000, 07/29/2004, 08/04/2004 and 09/13/2007).
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Issue Date: April 28, 2016
DIVISIONAL DIRECTOR OF PATENTS
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NAHANNY CANAL REYES
Arenal No. 550. Floor 1<sub>: </sub>i heard Santa María Tepeoar Town,
Xochimiteo. CP 16020,
Mexico City I read. (55, 53 34 07 00 wwy¿ »mpi gt> b.mx
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MX / 2016/32870
MEXICAN INSTITUTE ηε La froRienal »
Industrial
SYSTEM AND METHOD FOR INVESTIGATING CHARACTERISTICS
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SUBSUPERFICIALS OF A ROCK FORMATION
Field of the Invention
The present invention generally relates to seismic interrogation of rock formations and more particularly to creating three-dimensional images of nonlinear properties and / or the compression to shear rate ratio in a remote region of a hole using a combination of sources in a auger, and to receive and analyze a third resulting wave formed by a mixing process.
Background of the Invention
The acoustic interrogation of subsurface characteristics tends to be limited by the size and power of practical sources, and in practice, the output of bore acoustic transducers is limited by the power transmission capabilities of the wireline cable. High-frequency signals have a relatively short penetration distance, while low-frequency signals generally require large sources, attached to the walls of the hole, to maximize energy transfer to the formation and minimize unwanted signals within the hole .
Currently, acoustic drill tools are
REF .: 257648 ar 1 «τΐΐητηmexicana ót La ί'βηΊΕήΛΒ V iNW'STWlAL designed with acoustic sources in the hole to detect return acoustic waves that propagate along the walls of the hole or are dispersed by non-homogeneities of linear properties of rock formations surrounding the hole. US Patent No. 7,301,852 to Leggett, III et al., Describes a Drilling Drill tool, designed to detect rock formation boundaries. The tool uses two sound source arrangements that emit two sound waves from a hole that generate a third wave by nonlinear mixing in the rock formation surrounding hole in the location of the sound wave intersection. The third wave continues forward and interacts linearly with heterogeneities in subsurface properties. The third wave is scattered by heterogeneities in subsurface properties and the scattered signal is detected by sensors in the recording tool. US Patent No. 7,301,852 does not describe detecting the third wave directly but rather the signal that is scattered by heterogeneities in the rock formation. US Patent No. 7,301,852 simply uses the resulting scattered wave to detect boundaries in rock formation.
Attempts have been made to characterize the nonlinear properties of a formation in the area of prospecting for oil and gas from drillholes, but each
IMPIAS
MEXICAN INSTITUTE
OF THE PRORITY Q
INDUSTRIAL where the receiver and sources are located in a hole.
<img file="MX338705B_D0006.tif" />
In view of these previous attempts, there is a need for a system and method to characterize nonlinear properties in a remote region from a hole.
Brief Description of the Invention
One aspect of the present invention is to provide a method of investigating rock formations outside of a hole. The method includes generating a first sound wave at a first frequency by a first sound source; and generating a second acoustic wave at a second frequency by a second acoustic source. The first and second acoustic sources are arranged within a localized area of the hole. The first and second sound waves intersect in an intersecting volume outside the hole. The method further includes receiving a third sound wave at a third frequency, the third shear sound wave returns to the hole due to a non-linear mixing process in a non-linear mixing zone within the intersection volume at a receiver arranged in the hole . The third frequency equals a difference between the first frequency and the second frequency.
Another aspect of the present invention is to provide a system for investigating rock formations.
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IMPI
INSTITUTO MEXICANO PE LA PROPIEDAD INDUSTRIAL out of a hole. The system includes a first acoustic source configured to generate a first acoustic wave at a first frequency; and a second acoustic source configured to generate a second acoustic wave at a second frequency. The first and second acoustic sources are arranged within a localized area of the hole. The first and second sound waves intersect in an intersecting volume outside the hole. The system further includes a receiver arranged in the hole and configured to receive a third sound wave at a third frequency, the third shear sound wave returns to the hole due to a non-linear mixing process in a non-linear mixing zone within the volume intersection. The third frequency equals a difference between the first frequency and the second frequency.
In some aspects of the present invention, the first sound wave and the second sound wave include encoded sound signals. In other aspects of the present invention, the first and second acoustic sources are configured to generate conical transmission acoustic signals. In further aspects of the present invention, a system and method is provided for imaging nonlinear properties of the rock formation, or determining a compression rate, determining a shear rate, or determining a ratio of
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IMPI '^ 3 ^ 1
MEXICAN INSTITUTE .-.
OF THE FROPUDAÍi i -a
INDUSTRIAL speed between compression speed and <sup>xw</sup> J ·? · Shear in the rock formation, or any combination thereof.
In yet another aspect of the present invention, a system is provided for investigating nonlinear properties of a rock formation around a hole. The system includes a first subsystem configured to carry out data acquisition, control and record data; a second subsystem in communication with the first subsystem and configured to perform preliminary nonlinearity and velocity imaging; a third subsystem in communication with the first subsystem configured to emit controlled acoustic broadcasts and receive acoustic energy; a fourth subsystem in communication with the first subsystem and the third subsystem and configured to generate a source signal directed toward the rock formation; and a fifth subsystem in communication with the third subsystem and the fourth subsystem and configured to perform signal detection representative of the nonlinear properties of the rock formation.
These and other objects, features, and functions of the pr esent invention, as well as the methods of operation and functions of related elements of structure and the combination of parts and manufacturing economies, will become more apparent after consideration of
IMPI
MEXICAN INSTITUTE
FROM THE PROPERTY ~ / industrial the following description and the appended claims with reference to the accompanying figures, all of which form a part of this description, where equal reference numbers designate corresponding parts in the different figures. However, it should be expressly understood that the figures are for illustration and description purposes only and are not intended as a definition of the limits of the invention.
As used in the description and in the claims, the singular form of one, one, el and include plural referents unless the context clearly dictates otherwise.
Brief Description of the Figures
Fig. 1 shows a configuration for creating three-dimensional imag es of nonlinear properties in a remote region of a hole, in accordance with various aspects of the invention.
Figure / 2 'shows another configuration for creating three-dimensional images of nonlinear properties in a remote region of a hole, in accordance with aspects of the invention.
FigurX ^ shows yet another configuration for creating three-dimensional images of nonlinear properties in a remote region of a hole, in accordance with aspects of the invention.
MEXICAN INSTITUTE OF EROPHITY industrial i
Figure 4 shows a flow chart for creating three-dimensional images of nonlinear properties in a remote region of a hole, in accordance with various aspects of the invention.
Figures 5a, 5b and 5c show a numerical simulation of the first selection rule for a beam-beam interaction listed in Table 1 when the two primary waves are beams.
Fig \ EtaT 6 illustrates the geometry of the generation of the third wave of difference frequencies by non-linear mixing of two primary acoustic waves governed by the non-linear mixing selection rule.
Fig. 7 shows an application of aspects of the present invention to image using a beam and wide beam or plane wave.
Fig. 8 shows a configuration example for a hole-based system for the formation of remote maps of nonlinear properties and / or Vp / Vs ratio of rock formations using non-collinear acoustic mixing, according to one aspect of the first invention.
Fig. 9a shows the configuration of Fig. 8 for the purpose of identifying vectors that represent scattered and transmitted acoustic waves.
Figure 9b shows a vector representation of the non-collinear acoustic mix of Figure 9a.
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Fig. 10a shows a representative dependence of the mixing coefficient on the ratio of plane wave frequencies for a mixing zone compression rate range and shear rate ratios Vp / Vs, in accordance with aspects of the present invention.
Figure 10b shows a representative dependence of convergence angles with plane wave frequency ratio that comply with the selection rules for the P + P interaction.<sup>1</sup>^ SV.
Figure 10c shows a representative dependence of dispersion angles with plane wave frequency ratio that comply with the selection rules for the interaction Ρ + ΡΦ SV.
Figures lia, 11b and 11c show example of results of a numerical simulation of non-collinear interaction of flat waves in a non-linear medium that leads to the generation of a scattered wave that returns to the hole, in accordance with aspects of the present invention.
Figure 12a shows an example of the representation of directions and flight times for primary and scattered sound waves in accordance with aspects of the present invention.
Figures 12b, 12c and 12d show an example of a simulated signal from a first acoustic source,
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MEXICAN INSTITUTE Μ
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INDUSTRIAL a simulated signal from a second acoustic source and a simulated template signal, according to an embodiment of the present invention.
Figure 13a shows a position of a first acoustic source and a second acoustic source and a receiver arrangement, in accordance with an embodiment of the present invention.
Figures 13b, 13c and 13d show how the correlation of the received pulse series with a modeled template signal results in the identification of the signal arrival time in the receiver arrangement, according to an embodiment of the present invention .
Figure 14a shows a position of a first acoustic source and a second acoustic source and a receiver arrangement, in accordance with an embodiment of the present invention.
Figures 14b, 14c and 14d show the effect of transmitting a series of coded pulses and using correlation techniques to improve the signal-to-noise ratio, in accordance with aspects of the invention.
Figures 15a and 15b show an example of a non-collinear mixing arrangement in a toroid around the hole at the intersection of two coaxial cones, in accordance with aspects of the present invention.
Figures'! 6a and 16b show an example of a
<img file="MX338705B_D0009.tif" />
non-collinear mixing arrangement between two intersecting coaxial cones, in accordance with aspects of the present invention.
Figure 17a shows an example of a single well arrangement with an angled hole where there is a complete intersection of lower cone with upper cone, in accordance with aspects of the present invention.
Figure 17b shows another example of a single well arrangement with an angled hole where a lower transmitter emits energy almost perpendicular to a hole axis, in accordance with aspects of the present invention.
Fig. 18a shows an example of a vertical well and side rail with receivers in the vertical part of the well, in accordance with aspects of the present invention.
Figure 18b shows another example of a vertical pilot hole and horizontal side rail with receivers in the side rail, in accordance with aspects of the present invention.
The figures are a schematic system diagram of a system for carrying out probing design, data acquisition, data processing, and imaging, in accordance with aspects of the present invention.
Detailed description of the invention
Figure 1 shows one of several possible configurations for creating three-dimensional property images.
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INSTITUTOMEXICANO Í'U IA PROPIEDAD
IN »USTRIAL nonlinear and the ratio of compression speed to shear in a remote region of a hole according to various aspects of the invention. The first acoustic source 105 is arranged in the bore 110 to generate a steerable primary beam of acoustic energy at a first frequency £ ¿. The second acoustic source 115 is also arranged in the bore 110 to generate a directible primary beam of acoustic energy at a second frequency f<sub>2</sub>. By way of a non-limiting example, both the first acoustic source 105 and the second acoustic source 115 can be a phased array of sources and can be configured to generate either compression or shear steerable beams. In the present invention, the term acoustic can refer to acoustic mode P, SV, or SH.
As shown in Fig. 1, the first sound source 105 is arranged in the first tool body 120 and the second sound source 115 is arranged in the second tool body 125. However, the invention is not so limited since the first tool body 120 and second tool body 125 may also be arranged together in a common tool body (not shown). Tool bodies 120 and 125 are arranged to be able to move independently within bore 110 at least two degrees of freedom including translation along the axis
<img file="MX338705B_D0012.tif" />
longitudinal 150 of hole 110 and rotation 155 in azimuth about the longitudinal axis of hole 110. The first sound source 105 can be arranged above or below the second sound source 115 in hole 110. Tool bodies 12 0 and 125 can be arranged in a logging tool transported (not shown) within hole 110.
For a given azimuth orientation of the first sound source 105 and the second sound source 115, the beam generated by the second sound source 115 and the beam generated by the first sound source 105 are configured such that the beams converge and intersect at mixing zones
130 remote from hole 110. By a combination of independently directing the beams and changing the spacing between sources 105, 115, the mixing zones 130 move in a plane defined by the beams and the longitudinal hole axis 150, while controlling the angle intersection. The distance of mixing zones 130 from hole 110 can vary from almost the edge of hole 110 to approximately 300 meters within the surrounding subsurface rock formation. By way of a non-limiting example, the phase difference and / or start time differences between adjacent elements in the source arrangement 105, 115 mentioned in the preceding paragraphs can be modified to focus the acoustic energy of the beams at ivi ri
<img file="MX338705B_D0013.tif" />
primaries in a particular mixing zone 13 0 ..
The nonlinear properties of the earth at the location between the two waves translate into the generation of a third elastic wave. The third elastic wave is the result of a three-wave mixing process that occurs in nonlinear materials, in this case, rock formations. In this process, two converging non-collinear waves of different frequencies, and f<sub>2</sub>Also called primary waves, they mix to form additional waves at the harmonic and intermodulation frequencies f<sub>2</sub>-F<sub>2/</sub> fi + £ 2, 2xf<sub>2 </sub>and 2xf<sub>2</sub>, etc. The power of the third wave is a function of the nonlinearity of the rocks in the mixing zones. Ά as a non-limiting example, when a primary compression wave (P) with a frequency jf<sub>2</sub> and a primary shear wave (SV) with a frequency f<sub>2</sub> crosses or intersects in a non-linear medium, a third compression (P) or shear wave (SV) is generated with a frequency fl-f2.
Under the propagation selection rules, the third wave propagation vector is coplanar with the propagation vectors of the two primary waves. Certain combinations of intersection angle, fl-f2 ratio and compression to shear rate ratio translate into a third elastic wave with frequency fl-f2 that propagates at a specific angle relative to the
<img file="MX338705B_D0014.tif" />
INSTITUTO MEXICa »m <> VW LA FWhír 'NOUSTRIAL primary beams back to hole nn. -
Sensor or receiver array 135 is arranged at a specific location in hole 110 to detect the third wave returning to hole 110. In one embodiment, as shown for example in Figure 1, sensor array 135 comprises more than a sensor, arranged as an array of sensors in sensor tool body 140 and spaced apart from tool bodies 120 and 125. Sensor 135 is configured to be independently movable within hole 110 along longitudinal axis 150 of hole 110. For example, sensor tool body 140 may be disposed below tool bodies 120 and 125 or disposed above and below of tool bodies 12 0 and 125. In some embodiments, sensor tool body 140 may be connected to either or both of tool bodies 120 and 125.
The third wave is detected in hole 110 by sensor array 135. Figure 2 shows an arrangement similar to that of Figure 1, where receiver 135 includes three component geophones 145 attached to the hole walls. The resulting signal is decomposed by processing at its elevation and azimuth to thereby add redundancy to the system by determining the direction of arrival of the third incoming wave.
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MEXICAN INSTITUTE $
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INDUSTRIAL
In one embodiment, a first processor <
Controller may be provided and configured to execute machine-readable instructions (not shown) to perform various processing tasks, such as controlling source burnout and compression or filtering of data recorded by sensor array 135. In one embodiment , the first processor can be arranged within hole 110. In one embodiment, a second processor may be provided and configured to execute machine-readable instructions (not shown) to assist the first processor or to perform different processing tasks than those of the first processor. For example, the second processor may carry out part or all of the processing activities in creating the three-dimensional images. A transmitter or transceiver (not shown) can be arranged in hole 110 to transmit data up the hole through a wireline cable (not shown). In one embodiment, the second processor may, for example, be disposed outside the hole.
At a given depth along the hole in one of the sources 105, 115, the sweep of the rising beams to a constant relative support to spatially scan the mixing zone in a plane passing through the hole axis, making rotate the sources into shape
<img file="MX338705B_D0015.tif" />
azimuth to rotationally sweep the mixing region and move the entire assembly along hole 110, results in scanning a 3D volume of mixing zones around the hole for non-linear properties. With sources 105, 115 and arrangement of sensors 135 located in independent tool bodies, redundancy in the data can be obtained and the depth of investigation can be varied. In this way, a 3D volume of the rocks surrounding the hole can be interrogated for nonlinear properties and a 3D image of the nonlinear properties can be processed and calculated from the returned signals, i.e. signals detected by the arrangement of sensors 135.
Figure 3 shows another arrangement for creating three-dimensional images of nonlinear properties in a remote region of hole 110 in accordance with another embodiment of the present invention. The arrangement of Figure 3 is similar to the arrangement of Figure 2, with the main difference being that the sources are arranged in the bore 110 to produce elastic waves (eg, spherical waves) instead of steerable directional beams. Referring to Figure 3, the first acoustic source 305 is disposed in the bore 110 in the first tool body 320 to generate a first elastic wave of acoustic energy at a first frequency fi. The second
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<img file="MX338705B_D0016.tif" />
acoustic source 315 is arranged in hole 110 on the second tool body 325 to generate a second elastic wave of acoustic energy at a second frequency f<sub>2</sub>. The first and second elastic waves produced by sources 305, 315 are arranged to intersect away from hole 110 in various mixing zones 130. Receiver 145 is arranged within hole 110 to receive a third wave that occurs in mixing zones. 13 0 by the three-wave mixing process described above, and described below. Since the waves produced by the sources 305, 315 are essentially non-directional, the mixing between the waves occurs simultaneously in the entire area of the mixing zones 130, which also extends out of the plane of the figure, and the receiver 145 tends to have directional characteristics. By way of a non-limiting example, an arrangement of three component geophones can be used for this purpose. The resulting signal is decomposed by processing into various arrival signals over a range of elevations and azimuths and travel times. Given the locations of sources 305 and 315 and receivers 145, travel times, and directions of each decomposed directional arrival, there is sufficient information to apply selection rules described in the following paragraphs to determine a unique mixing zone where it was generated. the third wave. This unique assignment allows the
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<img file="MX338705B_D0017.tif" />
construction of a three-dimensional (3D) image from the properties of the received signal.
Figure 4 shows a flow chart for a method of creating three-dimensional images of nonlinear properties and the compression rate to shear in a remote region of a hole using a transported logging tool, in accordance with an embodiment of the present invention. . The method starts at 405 where a first acoustic source is arranged in the hole to generate a beam directional elastic energy at a first frequency and a second acoustic source is placed in the hole to generate a directional elastic energy beam at a second frequency. . The steerable beams on the first and second frequencies are arranged to intersect at a location away from the hole. In this way, the second beam is generated at the same azimuth as the first beam, but at a different elevation relative to the hole's longitudinal axis. The method continues at 410 where a third elastic wave is received in the hole by an array of sensors. As described above, the third elastic wave is created by a mixing process, with a frequency equal to a difference between the first and second frequencies and a direction of propagation towards the hole. In 415, a mixing location away from the hole is determined from the arrangement of the first and second sound sources and
<img file="MX338705B_D0018.tif" />
third wave properties, by recourse to selection rules. At 420, three-dimensional images of nonlinear properties are created using recorded data by repeating the generation of step 405, the reception of step 410, and the determination of step 415 at a plurality of azimuths, elevations, and longitudinal locations within the hole. . In cases of compression-shear interaction, the received signals are analyzed in step 425 for the compression-shear rate ratio (Vp / Vs) as described in the preceding paragraphs. In 430, nonlinear properties are transformed into physical reservoir properties such as fluid saturation, effective stress, fracture density, and mineralogy.
In some aspects of the present invention, the first and second acoustic sources may be cylindrical or spherical beam wave sources, and the sensor arrangement may be any combination of non-directional single-component sensors and three-component geophones. Alternative permutations of component parts offer different degrees of redundancy in signal processing and imaging.
In the special case where a primary compression wave (P) with a frequency and a primary shear wave (S) with a frequency f<sub>2</sub> cross each other, in a nonlinear medium, a third P or S wave is
<img file="MX338705B_D0019.tif" />
generates with the frequency fi-f<sub>2</sub>. If the primary waves P and S are beams with wave vectors k<sub>3</sub> and k<sub>2</sub>, respectively, and the non-linear formation property is uniform, the wave interaction kinematics requires that the resulting third wave be a plane wave with wave vector k<sub>3</sub> to obey selection rule k<sub>3</sub>-k<sub>2</sub> = k<sub>3</sub>. The selection rule imposes a very narrow constraint on the allowable crossover angles for the primary waves and a specific propagation direction for the third wave. The general kinematic theory for nonlinear mixing of two linear plane waves and the amplitude selection and response rules have contributions from Jones and Kobett (1963), Rollins, Taylor et al., (1964) and later by Korneev, Nihei and Myer (1998), all of which are incorporated herein by reference in their entirety, who also provide specific relationships between nonlinear parameters of the mixing medium and the power of the nonlinear mixing signal. For example, Korneev, Nihei, and Myer equations 53 and 54 show that the flat wave mixing power P and SV (vertically polarized shear) is proportional to a specific combination of nonlinear rock parameters.
The selection rules governing the nonlinear interaction of two elastic plane waves can be used as a guide for the interaction of two elastic beams. These rules of<sup>Ν</sup> MEXK.AW, ιέ The RROHeimp industrial
<img file="MX338705B_D0020.tif" />
Plane wave selection dictates that the following six nonlinear interactions produce backscattered waves.
Table 1
Selection rules governing the nonlinear interaction of two elastic flat waves. In this table, and anywhere in this document, it is greater than £<sub>2</sub>.
<td>Rules of</td><td> 1<sup>er</sup> beam or wave</td><td>2nd beam or wave</td><td> 3<sup>er</sup> do u</td>
<td>selection</td><td></td><td></td><td>wave</td>
<td></td><td></td><td></td><td>resulting</td>
<td></td><td></td><td></td><td>1st + 2nd</td>
<td> 1</td><td>P (fJ</td><td>SV (f<sub>2</sub>)</td><td>P (f<sub>2</sub>-F<sub>2</sub>)</td>
<td> 2</td><td>P (fJ</td><td>SV (f<sub>2</sub>)</td><td>SV (f<sub>2</sub>-F<sub>2</sub>)</td>
<td> 3</td><td>P (fxJ</td><td>SH (f<sub>2</sub>)</td><td>SH (f<sub>2</sub>-F<sub>2</sub>)</td>
<td> 4</td><td>P (fj</td><td>SV (f<sub>2</sub>)</td><td>Peff-fz)</td>
<td> 5</td><td>SV (fJ</td><td>SV (f<sub>2</sub>)</td><td>Ρ (Λ-ίζ)</td>
<td> 6</td><td>SH (fJ</td><td>SH (f<sub>2</sub>)</td><td>P (f<sub>2</sub>-F<sub>2</sub>)</td>
Figures 5a, 5b and 5c show a numerical simulation of selection rule 1 in Table 1 when the two primary waves are beams of a beam-beam interaction. A 25 kHz compression beam, shown in Figure 5a, and an 18 kHz shear beam, shown in Figure 5b, mix to form a third beam, shown in Figure 5c, with a frequency of 7 kHz = 25 kHz - 18 kHz. In this example, from
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<img file="MX338705B_D0021.tif" />
according to the predictions of plane waves, a third beam P of propagation backwards frequently (fy-íy) at an angle of 133 ° to the wave P (f<sub>2</sub>) is generated by nonlinear mixing in the region where beams P (f<sub>2</sub>) and SV (f<sub>2</sub>) overlap.
The kinematics of nonlinear beam interactions results in the generation of specific combinations of wave vectors and frequencies. The third wave returns at a specific travel time, and with specific frequencies f<sub>3 </sub>and k wave vectors<sub>3</sub> such as f<sub>3</sub>= f<sub>1</sub>-F<sub>2</sub> and k<sub>3</sub>= k<sub>1</sub>-k<sub>2</sub>. For a combination of £ i, £<sub>2</sub>, k<sub>2</sub> and k<sub>2</sub>, there is a wave vector k<sub>3</sub> well-defined propagation of the third wave in the same plane, defined by k<sub>2</sub> and k<sub>2</sub>. There is a direct correspondence between the signal detected at a particular receiving position and the location where the nonlinear mixing of the two primary waves k<sub>2</sub> and k<sub>2</sub> occurs. The signal power of the receiver would be proportional to the power of the nonlinearity of the rocks in the mixing zone, among other factors, and reaches a maximum for a receiver that rests on the vector k<sub>3</sub>. Therefore, the signal power at the receivers can be geometrically assigned to the nonlinearity of the rocks along the beam path as shown, for example in Figure 1.
Geometric wave propagation theory indicates that the gas generated in each mixing zone would reach the hole in a specific receiver defined by the geometry
<img file="MX338705B_D0022.tif" />
of the three k wave vectors<sub>x</sub>, k<sub>2</sub> and k · ?, after a specific time delay. The strength of the return signal at a specific location in the hole at a particular time depends on the degree of non-linearity of the interaction location. Accordingly, a time image of the relative power of the nonlinear properties of the rocks along them can be constructed. The amplitude or magnitude of a signal returned at the receivers may in turn be indicative of certain petrophysical properties of the mixing zone. If the beam and plane wave are scanned at azimuth and elevation while maintaining the angle of convergence, a localized radial and circumferential 3D image of nonlinear properties of rocks surrounding the hole can be obtained. By moving the entire assembly up and down the hole, repeated 3D images of nonlinear rock properties surrounding the hole can be obtained. By making weighted piles of these repeated images, a final image of nonlinear properties of rocks surrounding the entire hole can be constructed through subsequent computer processing. Also, if the sources and receivers are part of three separate tool bodies, one or two can move while the third is fixed (for example, the sources are fixed while the receiving tool body is moved up. Alternatively, several
IMPI Mexican INSTITUTE OF PROPERTY IN m'ST RIΛ l with different spacing declines in the well can be made between tool bodies.
For nonlinear mixing between an elastic beam and a wider beam (almost flat wave), the selection rule is relaxed. Third waves of frequency fi = f<sub>2</sub>, centered around wave vector k<sub>3</sub>= ki-k<sub>2</sub>, are continuously generated along the primary beam if the beam width is approximately ten wavelengths of the third wave. The resulting signal strength for f<sub>3</sub> = f<sub>2</sub>-F<sub>2</sub> is a function of the average nonlinear properties of the mixing region, the average propagation velocity ratio fj, and the average propagation velocity f<sub>2</sub> (noting that you do them with frequencies f<sub>3</sub> and f<sub>2</sub> they can be compression or shear), the volume of the mixing zone and the geometry of the mixture. This function can be calculated for various mixing modes. For example, the signal strength for a particular mixing mode such as compression wave P for f<sub>2</sub> and SV for f<sub>2</sub> is given by / 1/2 (/ - / 2)
F Λ <sup>1</sup> PSvP ^ PSf (1) where U is the displacement amplitude of the third wave received in the hole, A<sub>3</sub> is the longitudinal polarization of the compression wave and B<sub>2</sub> is the transverse polarization of the shear wave. β is a function of Landau and Lifschitz parameters A, B and C that represent
<img file="MX338705B_D0023.tif" />
the non-linearity of the rocks in the mixing zone, v is the volume of the mixing zone, L is the distance from the mixing zone to the receiver. F is the geometric form factor of order 1 that depends on the geometry of the incident beams and can be calculated numerically for the particular geometry. Δ is a selection rule form factor that is a numerically computable function of the wave vectors ki, k<sub>2</sub> and k<sub>3</sub> and it is only significant if the interaction geometry complies with the selection rules.
The PSvP subscript in the formula refers to the compression-shear interaction generated by a compression wave.
In accordance with certain aspects of this invention, an image of the compression to shear rate ratio can be constructed as follows. When one of the sources generates a compression wave (P wave) with frequency fi and the other source generates an SV wave with frequency f<sub>2</sub> and both waves are directed towards a specific intersecting volume, the propagation direction of the third compression wave (P wave) with difference frequency f<sub>3</sub>= f<sub>2</sub>-F<sub>2</sub> It is controlled by the speed ratio Vp / Vs in whether your average of the rock in the mixing zone governed by the selection rules as shown in figure 6. From the signal measurements in the array of three components 145 in figure 2 or figure 3 the direction
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<img file="MX338705B_D0024.tif" />
of this third wave can be determined and in this way, the Vp / Vs in si tu of the mixing zone can be calculated. If the beam and plane wave are scanned in azimuth and elevation while maintaining the required angle of convergence, a localized radial and circumferential 3D image of the Vp / Vs in if ratio of rocks surrounding the hole can be obtained. By moving the entire assembly up and down the hole, repeated 3D images of Vp / Vs can be obtained in situ from rocks surrounding the hole. By making a weighted stack of these repeated images, a final Vp / Vs in situ image of rocks surrounding the entire hole can be constructed through subsequent computer processing. As an alternative, several descents in the well can be done with different fixed spacing between the tool bodies.
In some aspects of this invention, an alternative determination of the Vp / Vs ratio is accomplished through scanning the ratio of the frequencies f<sub>2</sub> af<sub>2</sub> of the primary beams. Figure 6 illustrates the geometry of the interaction of two beams such as those generated in the configuration of Figure 1, which can be analyzed using vector mathematics and trigonometry. Lengths k<sub>2</sub> and k<sub>2</sub> vector ki and k<sub>2</sub> they are defined by the relation of their corresponding frequencies and speeds.
As shown in Figure 6, the return angle φ is a
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<img file="MX338705B_D0025.tif" />
<img file="MX338705B_D0026.tif" />
INSTITUTO MEXICANO DE LA PROPIEDAD INDUSTRIAL function of fi / f2, the relation Vp / Vs and the angle of ^ -r<sup>2</sup>-2rcos /? -— + 2 = 0 cción intersection of two primary beams. Furthermore, the physical selection rules only allow the generation of a third wave in specific fi / f combinations.<sub>2</sub>, Vp / Vs ratio and intercept angle Θ, such as the example illustrated in Figures 5a-5C.
Using the symbol r for the relation Vp / Vs and the terms defined in figure 6, the magnitude k<sub>3</sub> vector k<sub>3 </sub>is given by the sum of vectors of ki and -k<sub>2</sub>, that is * and also by the cosine rule that indicates k<sub>3</sub><sup>2</sup>= k3<sup>2</sup>+ k2<sup>2</sup>-2k<sub>1</sub>k<sub>2</sub>cos0. Combining the two equations, and substituting k<sub>3</sub> with fi / Vp and k<sub>2</sub> with f<sub>2</sub>/ Vs, an indication of the geometric conditions imposed by the selection rules is achieved. The quadratic equation can be solved for r, the relation
Vp / Vs of the mixing zone. This leads to a non-limiting alternative method of measuring Vp / Vs ratio in situ of a particular mixing region by the following sequence: a) recording a logarithm of the standard sonic waveform to determine Vp and Vs near the hole to acquire data to estimate the phase differences between adjacent elements in a phased array of sources to direct the beams to the approximate angle of convergence for the planned measurement geometry, · b) directing sources P and SV to converge at an angle
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<img file="MX338705B_D0027.tif" />
controlled Θ and mix in a particular region in space surrounding the hole; c) vary f<sub>2</sub> while fixing f<sub>2</sub> and measure the amplitude of the received signal at the difference frequency fi ~ f<sub>2</sub> on the sensors in the hole; d) identify the frequency at which the signal that each receiver in the arrangement reaches a maximum amplitude force; and e) determine angles Θ and φ from the geometry of the sources and receivers. When sweeping the beams in elevation, rotating in azimuth and moving the entire assembly up and down the hole and repeating the above procedure, the Vp / Vs ratio of a 3D volume around the hole is interrogated and thus images can be obtained 3D of the in-situ Vp / Vs ratio of rocks surrounding the hole.
The methods described above provide that the difference in frequency fi ~ f<sub>2</sub> it is very specific, allowing spectral analysis to increase the signal-to-noise ratio of the measurements. Furthermore, if both frequencies and f<sub>2 </sub>are modulated simultaneously proportionally, the frequency signal fi ~ f<sub>2</sub> resulting difference would also be a well defined modulated signal. The time variation code may include one or more than one variation in amplitude, a variation in frequency and / or a phase variation of the first, second or both the first and second beams or waves. The third difference wave can be broadband if one of the primary frequencies is swept through · «- ·« πλ 'riCUAi' inihistriai
<img file="MX338705B_D0028.tif" />
a range of frequencies while its frequency ratio is fixed. Thus, the resulting third beam f<sub>x</sub>-F<sub>2</sub> it will be swept across a wide frequency range, while preserving the same direction. This allows improvement in signal to noise by standard auto-correlation of the modulated or encoded signal.
Since the wave vector k<sub>3</sub> = k<sub>x</sub> - k<sub>2</sub> Well defined, third wave signal-to-noise discrimination recorded from receivers 135 can be further improved by employing three-component receivers in the hole. For example, the signals from all three components can be tuned to specific directivity by a technique, such as hodographic analysis.
In some aspects of the present invention, the signal to noise ratio can be improved by repeating the above steps and using reverse polarity source signals (180 degrees out of phase) and adding the results together. The return difference frequency signal will be added coherently since its amplitude is proportional to the product of the amplitudes of the two primary rounds and therefore will not reverse polarity when the polarity of the primary source is reversed. On the other hand, any linear noise generated by the primary sources in the system will reverse polarity and thus be canceled after addition.
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<img file="MX338705B_D0029.tif" />
Alternative methods with various non-exclusive beam and wave combinations can be envisaged. By way of a non-limiting example, a method of generating images by computer processing of acoustic and seismic signals includes the following steps. First, the method performs spectral analysis of the frequency content of the recorded third wave and applicable selection rules of the difference frequency signal to thereby isolate the third wave signal generated by the non-linear mixing process. In the event that the sensors include three-component geophones, the direction of the third wave colliding in the hole is determined using orientation techniques. The method continues by analyzing the amplitude of the third wave recorded as a function of frequency ratios of the primary mixing waves and determining the mix location where the third wave signals originated, from the mix selection rules not collinear in nonlinear media, the wave numbers of the first and second beams and the third wave and the locations of the two beam sources and the arrangement of sensors. The method continues by constructing seismographs determined by cross-correlating the received signals with affected transmitter signals for each source-receiver combination. The method continues by performing time or depth imaging
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<img file="MX338705B_D0030.tif" />
three-dimensional dataset of the entire dataset, to obtain three-dimensional margins of the nonlinear properties of the formation surrounding a hole in either or both of time and distance. Methods for generating images from seismographs are known, eg, Hill et al., Which is incorporated herein by reference, have provided the general methodology for the specific case of imaging from beams.
Another alternative and non-limiting imaging method is illustrated in Figure 7, which shows the case of interactions of a narrow beam 705 and a wide (wide) beam 710. Given a smooth background model of Vp and Vs of the investigated volume , the application of the selection rules makes possible the geometric allocation of the energy detected at a receiver location 735 on mixing zones 730 along the narrow beam. A time image of the nonlinear property can then be constructed along the narrow beam. By rotating the azimuth and moving the assembly along the hole, a three-dimensional time image can be constructed from a volume centered on the hole. Successive repetition of the measurement at different beam elevations, and alteration of the frequency ratio ¿2 / ^ 1 produces a series of three-dimensional time images. This redundancy in imaging allows additional refinement of the smooth background model and an image
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<img file="MX338705B_D0031.tif" />
three-dimensional space. ___
Nonlinear rock parameters have been found to be related to a number of important hydrocarbon deposit parameters, such as variations with gas, oil and water saturation, effective stress, fracture density and mineralogical content. In certain aspects of this invention, 3D images of nonlinear properties constructed by the above method are transformed to provide quantitative information about the distribution of these properties around the hole at the time of recording. Furthermore, sequential repeats of this method are used to detect changes in deposit properties over time for the purpose of monitoring deposits.
<td></td><td>The</td><td>records</td><td>of ways of</td><td>wave, received</td><td>I know</td>
<td>they process</td><td>for</td><td colspan="2">generate an image of</td><td>characteristics</td><td>not</td>
<td>linear</td><td>of the</td><td>training.</td><td>Directivity</td><td colspan="2">beam and time</td>
Flight attendants can fix the locations where scattered waves are generated, thus distinguishing this method from normal sonic imaging techniques using conventional non-directional monopole and dipole sources.
As a non-limiting example, when a primary compression wave (P) with a frequency f<sub>2</sub> and a compression wave (P) with a frequency f<sub>2</sub> intersect in a nonlinear medium, and the selection rules are upright, and
<img file="MX338705B_D0032.tif" />
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MEXICAN INSTITUTE,. ___ DE The industrial RRORIEDAO can generate a third shear wave (SV) with a frequency f<sub>2</sub>-F<sub>2</sub>. This particular configuration can be used to create 3D images of the velocity ratio Vp / Vs and nonlinear properties of the rock formations around the hole for many ranges of investigation distance from a hole. This particular example of nonlinear compression mixing to generate a shear wave (i.e. P + P -> SV) will be used to describe a number of new concepts, methodologies, processes, and systems for measurement and analysis purposes in the following paragraphs. These are equally applicable to P + SV -> SV or any non-linear mixing permutation of two acoustic compression or shear waves to generate a third wave.
Figure 8 shows a configuration example for a hole-based system for remote mapping of nonlinear properties and velocity ratio Vp / Vs of rock formations using non-collinear acoustic mixing in accordance with one aspect of the present invention. Two primary acoustic beams, eg compression waves (P), from upper and lower arrangements of transmitters 801 and 802 located in hole 800, are directed into the rock formation surrounding the hole. Transmitter arrangements can be oriented such that acoustic energy is propagated at any azimuth 809 and φ<sub>2</sub> 811 and elevation 810 already<sub>2</sub> 812 relative to the hole axis.
<img file="MX338705B_D0033.tif" />
For suitable elevation angles cx<sub>lz</sub> to<sub>2</sub> .and. angle j utliilUL and <t><sub>2</sub>, the two primary beams P that propagate through the rock formation intersect with the convergence angle Θ 8 04 in a mixing zone 8 05, away from hole 800. This convergence angle Θ is defined as the angle between the directions of the two converging beams, represented in figure 8 as the lines connecting the two transmitters 801 and 802 to the mixing zone 805. If the rock formation at the point of intersection properties does not
<td>linear,</td><td>a</td><td>wave</td><td>shear</td><td>Secondary SV (S)</td><td>(by</td>
<td>example,</td><td>a</td><td>wave</td><td>shear</td><td>polarized in the</td><td>flat</td>
<td>definite</td><td>by</td><td>the</td><td colspan="3">axes of the two compression waves</td>
intersecting is generated due to nonlinear interaction. The secondary shear wave propagates in a direction defined by the selection rules, represented by the scattering angle, ψ, 806. The scattering angle ψ, is defined as the angle between the axis of the acoustic wave coming from the lower transmitter and the axis of the scattered wave. In the configuration shown, power 807 returns to the hole and is registered to receiver or receiver arrangement 803.
As indicated above, the appropriate conditions for the generation of a secondary shear wave can be inferred from the selection rules that can be derived by conserving energy and conserving momentum. The secondary wave must obey the following
<img file="MX338705B_D0034.tif" />
(3)
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INDUSTRIAL (2) (4) (5) k<sub>3</sub> they are wave vectors. The first where f<sub>3</sub>= fi-f<sub>2</sub>, it is of interest conditions f3 = fl-f<sub>2</sub> k<sub>3</sub>= kx-k<sub>2</sub> or
f3 = fl + f<sub>2</sub> k<sub>3</sub>= k! + k2 where k<sub>3</sub>, k<sub>2</sub> and frequency condition, particularly for investigating properties of rock formations near a hole. As shown in figure 9, conditions (2) and (3) can be represented by the formation of wave-vector triangles and be satisfied by the following relationships (6), (7) and (8).
| k<sub>3</sub> | = 2π | fi-f<sub>2</sub>\ / Vs = (| f<sub>2</sub>-F<sub>2</sub>¡/ Vp) x (Vp / vs) (6) | ki | = 2nf<sub>3</sub>/ Vp (7) | k<sub>2</sub> | = 2ní<sub>3</sub>/ Vp (8)
Using trigonometry in the vector diagram in Figure 9b, it can be shown that these conditions can be met when equations (9) and (10) are satisfied.
fl n \ fl (9) sin (ψ) = (///}) x sin (θ) / (1 - ///) (10)
Since the velocity ratio Vp / Vs is in the range 1.5 to 3.0 for many sedimentary rocks, there are
<img file="MX338705B_D0035.tif" />
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As indicated above, the behavior of the acoustic energy generated by the non-linear interaction of intersecting non-collinear flat waves can be calculated. Selection rules define a set of allowed interactions. The P + P—> SV interaction is additional to the partial list in Table 1. These different interactions use certain combinations of angle of convergence, frequency ratio and angle of dispersion that depend on whether the convergence waves are compression or shear, on the ratio of the velocity Vp / Vs of the material at the interaction location, and they differ for interactions that generate energy of frequency in sum (fq + fy) and difference (fi-fs). The geometry presented in the following examples is based on the interaction P (ί<sub>2</sub>) + P (í<sub>2</sub>) <=> SV (f<sub>2</sub>-F<sub>2</sub>), and the analogs could equally occur for other interactions allowed by generating frequency resonance by difference or sum, for example, but not limited to, interactions including P (f<sub>2</sub>) + SV (f<sub>2</sub>) ^ SV (fi-f<sub>2</sub>) YP (fj + SV (f<sub>2</sub>) QP (fq-fj.
For example, considering P (f<sub>2</sub>) + P (í<sub>2</sub>) <=> SV (f2-í<sub>2</sub>), Figure 10a shows the mixing coefficient W as a
<img file="MX338705B_D0036.tif" />
IMPI function of the frequency ratio of the two sources. The mixing coefficient W, which is a measure of the amplitude of the conversion efficiency generated by the stray wave, is given by equation (11).
2 (Vs / Vp) (11) where D depends on the Lame coefficients λ and μ and is proportional to f<sub>2</sub>/ fi for a given mixing zone, as defined in equation (12).
D = ——
4τγ (Λ + 2 / ζ) (12)
Θ is the angle of convergence of the two primary beams in the mixing zone, and m is a scaling factor related to the nonlinear Landau-Lifshitz constants A and B, as expressed in equation (13),
A »m = —ι-B 2 (13)
Therefore, m is constant for a given mixing zone.
Figures 10a, 10b and 10c show the dependence of the mixing coefficient W, convergence angle and dispersion angle on the speed ratio Vp / Vs in the
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INSTITUTO MEXICANO Γ> ε THE PROPERTY ranges from 1.5 to 2.0 at the mixing location, assuming__ a representative value (from Korneev, Nihei and Myer (1998) for m of -3660 Gpa. Figure 10a of the mixing coefficient in the ratio of plane wave frequency for a range of Vp / Vs ratios of mixing zones Figures 10b and 10c show the corresponding convergence and dispersion angles that honor the selection rules for the P + P ^ SV interaction. As can be understood from figure 10a, the mixing coefficient reaches a maximum in a ratio of the second frequency f2 to the first frequency fl equal to approximately 0.7. Furthermore, from Figure 10b, it can be seen that when the ratio of the second frequency f2 to the first frequency fl is equal to about 0.7, the angle of convergence is in the range between about 30 degrees and about 40 degrees. Furthermore, it can also be seen that when the ratio of the second frequency f2 to the first frequency fl is equal to approximately 0.7, an angle of dispersion of the return wave with respect to a direction of the first wave is equal to approximately 40 degrees.
Figures lia to 11c show examples of numerical simulation results of non-collinear interaction of acoustic beams in a non-linear medium that leads to the generation of a scattered wave that returns to the hole. In Figures lia to 11c, the 1100 hole includes a transmitter
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MBXICAN INSTITUTE I) F INDUSTRIAL PROPERTY lower 1101, upper transmitters 1102 and arrangement of receivers 1103. Acoustic energy in the form of a compression beam generated by lower transmitter 1101 and upper transmission 1102 converges at a distance from the hole in the angle convergence 1104. Receiver arrangement 1103 is arranged to receive a scattered wave 1107 that is produced by the interaction of acoustic beams as defined by the selection rules, described above and again below, at the scattering angle 1106. In Figures lia, 11b and 11c, the distance along the hole in samples is shown against the radial distance away from the hole in meters. In figure lia and b, the volumetric stresses associated with the acoustic compression energy of the two beams produced by the two sources are shown. In Fig. 11c, the shear stress associated with the scattered shear wave 1107 is shown.
The following paragraphs describe a coded scheme that can be used to increment or extract measured acoustic waves originating from the nonlinear mixing of primary acoustic signals in a mixing zone within a rock formation around the hole. Scattered acoustic wave measurements generated from nonlinear acoustic phenomena in rock formations away from the hole can be increased by diffusing coded primary acoustic signals, recording the signal
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subsequently use a waveform recognition method and / or a bandpass filtration method based on the predicted properties of the non-linear signal. A non-limiting example is to correlate the recorded signal with a template that represents a forecast of its timing and frequency content derived from the transmission parameters according to the selection rules. The result of this correlation represents an acoustic pulse that travels beyond the hole. For example, in the case of the P + P-> SV interaction, the return energy resulting from the nonlinear interaction appears to travel along the hole at a speed equal to the shear wave velocity of the split formation between the cosine of the angle between its direction of propagation and the axis of the hole. When applied to a system such as that illustrated in Figure 8, the encoding and correlation method improves detection of the weak nonlinear signal and thus increases the construction of 3D images from nonlinear properties and the ratio speed Vp / Vs in the volume probed by the measurement.
A non-limiting implementation of using signal encoding and correlation for the increment of signals generated by non-collinear acoustic mixing in a non-linear medium is described in the following paragraphs. A
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INDUSTRIAL more detailed description for a further implementation
Generating
Properties and Characterizing non-linear acoustic general encoding scheme can be found in the US patent application entitled System and Method for
Micro-Seismic Events of a Medium with
Interactions, with Case No. 091230-0397046, filed pursuant to this application, the full contents of which are incorporated herein by reference. Referring to Figures 12a 12d, source 1201 begins to broadcast a first coded or modulated time stream Pi (t), consisting of a sequence of acoustic n-pulses, at time t = 0. The nth acoustic pulse has the frequency s<sub>n</sub> and an envelope of amplitude the<sub>n</sub>(tT<sub>n</sub>) of limited time duration, where n = l, 2 ... N and T<sub>n</sub> is the transmission time of the pulse number. The separation between time and pulse sequences is variable.
In some embodiments, the time spacing between sequential pulses is much longer than the time duration of the individual pulses, and the pulses do not overlap. A second encoded or modulated time train, or<sub>2</sub>(t) is broadcast from source 1202. This second encoded or modulated time stream consists of a sequence of n sequential acoustic pulses and begins at time t = δ, where δ is a difference in start time between a time start of a transmission the
<img file="MX338705B_D0039.tif" />
first codestream and a start time of a transmission of the second codestream. In one embodiment, the difference in start time can be understood as a time delay between the transmission of the first codestream and the second codestream. As can be seen, the transmission of the first codestream can
<td>be delayed</td><td>with</td><td>relation to</td><td colspan="2">transmission of</td><td>second train</td>
<td>encoded</td><td>or</td><td>vice versa. In</td><td>the</td><td>Present</td><td>description</td>
<td>Commonly</td><td>I know</td><td>you know δ</td><td>how</td><td>being a</td><td>delay of</td>
weather. However, δ should be broadly interpreted as a difference in time since the second pulse sequence can start before the first. The acoustic pulse number has the frequency of d * f<sub>n</sub> and an E2 amplitude envelope<sub>n</sub>(t- (Τ<sub>η</sub>+ δ)) of limited time duration, where n = l, 2 ... N. The frequency relationship between corresponding points in the two trains is fixed at d. Τ<sub>η</sub>+ δ is the transmission time of the pulse number. The amplitude envelopes El and E2 of the first and second coded signal streams, respectively, may be different or the same. Examples of the time-coded signal streams are shown in Figures 12b-12c. These encoded signals can be represented mathematically by the following formulas (14) and (15). In the present description the symbol * is used as a multiplication operator.
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Mi (í) = 22 E \ n {t - Tn) * exp (i 2ft * fn * {t -Tn)} exp (z ζη) n
(14) u<sub>2</sub>(t - 3) ~ ^ E2n {t - (Tn + J)) * exp (z 2π * d * f<sub>n</sub> * (t - (Tn + <5))) * exp (z ζη) n
(15)
<td>where ζ<sub>η</sub> is a:</td><td>to phase</td><td>of</td><td>every</td><td>pulse</td><td>n</td><td>and βχρ (ίζη) is</td><td>a</td>
<td>phase term</td><td colspan="2">every pulse</td><td>n.</td><td></td><td></td><td></td><td></td>
<td colspan="2">Wrappers</td><td>of</td><td>signal</td><td>The<sub>n</sub>(t-</td><td>• Tn)</td><td colspan="2">and E2 „(t- (Tn + d))</td>
<td>respective can</td><td>to have</td><td colspan="2">any</td><td>shape</td><td>or</td><td>setting</td><td>such</td>
like a gaussian form etc. Similarly, although the modulated signals within the envelopes are expressed in equations (14) and (15), they can be modulated by other mathematical formulas. When the time delay δ is equal to the difference in travel times ti and t2 (i.e. ó = tlt2) from transmitters 1201 and 1202 to mixing zone 1204, the corresponding acoustic energy of pulses n from the two trains The transmission frequency arrives simultaneously in the mixing zone and, if the convergence angle, frequency ratio and Vp / Vs ratio at the mixing location are in accordance with the criteria of the selection rules, generates a third series of scattered acoustic pulses with dominant frequency (ld) * fnz equal to the difference between the frequencies in the two primary pulses, f<sub>n</sub> yd * f<sub>n</sub>. This third wave, indicated u<sub>3</sub>,
<img file="MX338705B_D0042.tif" />
Registered at the receiver, it inherits the encoding of the lae-two> ... primary signals and can therefore be expressed as equation (16).
W3 (/) oc + r)) * exp (z2 ^ * (l-rf) * / „'(t- (T<sub>n</sub> + 7))) * exp (z £) n
(16) where ζ<sub>η</sub> is a phase of each pulse n and εχρ (ίζ) is a phase term of each pulse n of the third wave.
E3<sub>n</sub>(t) is the resulting amplitude envelope due to the mixing of the primary pulses and T is the type of total travel from source 1 to the recording receiver through the center of the mixing zone as explained below.
In one embodiment, signal enhancement can be accomplished using the well-known correlation technique in
<td>industry</td><td>of</td><td>processing</td><td colspan="2">seismic to extract a part</td>
<td>relevant</td><td>of</td><td>the interaction</td><td>nonlinear</td><td>and time information</td>
<td>Travel</td><td>in</td><td>the signal u<sub>2</sub></td><td>measure.</td><td>The technique includes the</td>
building a template sign u<sub>s</sub> having the form of a coded signal as expressed in equation (17).
^ (0 = Σ <sup>Wn</sup>(t <sup>T</sup>n) * exp (/ 2tf * g (Λ) * (t - T<sub>n</sub>)) * exp (zn
(Π) where ζ<sub>η</sub> is a phase of each pulse n and θχρ (ίζ<sub>η</sub>) is a phase term of each pulse n of the template signal.
W<sub>n</sub> is some properly selected wrapper function and g (f<sub>n</sub>) is some function
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suitably of the frequency function f<sub>n</sub>. Selecting a function g (f<sub>n</sub>) can be based on the shape of the expected modulated signal within the signal. measure u<sub>3</sub> to achieve the best non-linear signal extraction. For example, g (f<sub>n</sub>) can be selected to be (ld) * f<sub>n</sub> in such a way that u<sub>s</sub> equals as shown in figure 12d. However, other functions g (f<sub>n</sub>) are also within the scope of the present invention.
To extract the signals of nonlinear interactions in u<sub>3</sub>, a cross correlation between u<sub>3</sub> yu<sub>s</sub> it can be carried out to obtain the correlated signal M where M is defined mathematically by equation (18).
M (/) = J u<sub>3</sub> (/') * or<sub>s</sub> (t - / ') Λ' (18)
It can be shown mathematically that the resulting correlated M signal is a sharp band-limited peak with a bandwidth that includes all frequencies (1d) * fn for n = l, 2, ..., N when the number of pulses N is big. The term band-limited peak is used herein to refer to a peak signal that has limited frequency bandwidth. In one embodiment, increasing the transmission duration by increasing the number of N pulses improves the signals generated by the non-linear interaction in the correlated M signal while further suppressing
<img file="MX338705B_D0044.tif" />
INDUSTRIAL effective signals generated by linear interactions and other noise. It should be noted that the correlation technique using the coded signal pattern is one of many ways to extract and increase signals generated by nonlinear interactions. Alternative signal processing techniques including pattern recognition or frequency band filtering could equally be used for signal extraction and enhancement.
The measured and correlated signal M has the following properties. First, the correlated signal contains a sharp band-limited peak, which corresponds to the nonlinear interaction in the mixing zone, only if the time delay δ between the first and second primary encoded signals is equal to the difference between the travel time. at<sub>x</sub> from the first sound source 1201 to mixing zone 1204 and the travel time t<sub>2</sub> from the second acoustic source 1202 to mixing zone 1204, that is, 6 = t<sub>x</sub>-t<sub>2</sub>. If this condition is not satisfied, the correlated signal is highly suppressed. Second, if the condition δ = t<sub>x</sub>-t<sub>2</sub> is satisfied, the band-limited peak is presented in the correlated signal M (t) at time T which is equal to a sum of the travel time from the first primary sound source to the mixing zone and the travel time from the mixing zone 1204 to the receiver within the receiver arrangement
<img file="MX338705B_D0045.tif" />
1203, that is, T = t<sub>2</sub> + t<sub>3</sub> = δ + t<sub>2</sub> + t<sub>3</sub>. Third, increasing the duration of the coded signal stream, i.e. increasing the number of N pulses in the transmission stream, improves signal-to-noise discrimination<sub>and/ </sub>because the noise is not in the form of the template signal u<sub>s</sub>.
The numerical simulation is the result of a case where the lower transmitter 1201 and the upper transmitter 1202 emit two coded signal streams consisting of sequential acoustic pulses with Gaussian envelopes shown in Figures 13a-13d. In this non-limiting example, 12-pulse encoded signals are used with frequency pairs (574Hz, 373Hz), (624Hz, 405.6Hz) (700Hz,
455Hz) (757Hz, 492Hz) (802Hz, 521.3Hz) (870.5Hz, 566Hz) (947Hz, 615.5Hz) (1000Hz, 650Hz) (1120Hz, 728Hz) (1218Hz,
792Hz) (1324Hz, 861Hz) (1440Hz, 936Hz). The frequency ratio f<sub>2</sub>/ £ i between pairs is a constant 0.65. The start time delay δ between the two signal streams is selected to be equal to (tl-t2). Numerical simulation of nonlinear interaction due to transmission of the two coded wave trains u<sub>x</sub> yu<sub>2</sub> It is carried out on a computer. The signals simulated due to nonlinear interaction from a transmission of two sequential pulses received and recorded in six out of 110 receivers, indexed from 1 to 110, in the non-limiting example τ
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^ 'THUTOMÍXICAN, VZtíZi M IjA ΡΚΟιΊΕΡΛΙ CV INtMISTKlAt of an array of 1203 receivers are shown in Figure 13b. The template u<sub>s</sub> for the return encoded signal is shown in figure 13c. The result of the correlation between the template signal with the signal registered in each receiver is shown in Figure 13 (d). The resulting correlated signal at each receiver shown in Figure 13d shows a very sharp band-limited peak. This sharp peak occurs at time T = tl + t3 where ti is the travel time from source 1 to the center of the mixing zone and t3 is the travel time from the center of the mixing zone to the receiver. Time delays or overtime by distance through the array of receivers is as if the acoustic energy is traveling along the hole with an apparent velocity equal to the shear wave velocity divided by the cosine of the angle between the direction of the return wave and the hole axis.
The numerical simulation based on Figures 13a13d clearly illustrates the power and usefulness of the coding scheme when used in conjunction with the measurement system of Figures 12a-12d or Figure 8. It allows computer processing of the signals recorded at the receivers. to generate correlated records containing band-limited peak signals with power proportional to the power of the nonlinear interaction in the
AJb ______r j ίΜβτιτιίτη MEXICAN mixing zone 1204. The arrival time T of the band-limited peak is equal to the total travel time from source 1201 to mixing zone 1204 and back to the hole at receiver 1203. The amplitude of the band-limited peaks varies with the position of the receiver with a maximum occurring at a particular receiver, the location of which depends on the dispersion angle ψ 12 06 of the nonlinear interaction in mixing zone 1204. The angle of dispersion ψ depends on the properties of the rocks, for example speed ratio Vp / Vs, in the mixing zone 12 04. It should be noted that this result is a characteristic of the coding scheme and measurement system shown in Figures 12a-12d or Figure 8. The use of Gaussian envelopes and encoded signals in conjunction with templates are non-limiting examples used for purposes of illustrating the encoding scheme and its features. Variants of Ui, u<sub>2</sub> yu<sub>s</sub> they can be considered to optimize the performance of the correlation process in terms of resolution and signal-to-noise ratio in response to various considerations imposed by field applications.
In some aspects of the present invention, encoded acoustic signals in the primary acoustic beam can also be used to improve the amplitude and focus of the nonlinear signal returning to the hole, and to improve signal detection sensitivity and signal to signal ratio.
<img file="MX338705B_D0047.tif" />
noise. Figures 14a-14d show a —eJ'LUlljJltL · '”application of the encoded signal scheme to a noisy time series signal generated by numerical simulation. The noisy serial time signal simulates a signal that returns to the hole as a result of nonlinear interaction. White Gaussian noise with an amplitude 10¾ greater than the amplitude of the nonlinear interaction signal is added to the time series signal produced by the numerical simulation of wave propagation in a nonlinear model before correlation with the template coding is applied. The configuration is the same as that shown in Figures 12a12d and Figures 13a-13d. Figure 14b shows the simulated noise-containing receive signal recorded at 6 receivers of the receiver arrangement 1403. Figure 14d shows the signal recovered from the noisy signals (in this case the simulated noisy signals) at the same receivers when maps to the encoded template u<sub>s</sub> 12-pulse (t) shown in Figure 14 (c). Coding schemes are then shown to effectively extract the signal from nonlinear interaction and minimize noise, a useful feature for field applications.
The text above described how a combination of signal encoding and signal processing can be used to improve detection and to determine the
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<img file="MX338705B_D0048.tif" />
amplitude of an acoustic wave signal generated by non-collinear mixing in a non-linear medium and to determine the acoustic travel time of sources to the disposition of receivers through the mixing zone and to infer the non-linearity and Vp / Vs ratio of the mixing zone. The following paragraphs describe a non-limiting implementation of the signal encoding and processing method in the context of a hole-based measurement system.
Given a model of compression velocity and initial shear rate of formations around the hole, techniques such as ray tracing can be used to estimate the location of a mixing zone, 805 in Figure 8, corresponding to selected inclinations and azimuths (α<sub>χ</sub>, α<sub>2</sub>, φι and φ<sub>2</sub>, 809 to 812) and also the angles of convergence and dispersion (θ and ψ, 804 and 806). This information is used to predict the time delay δ<sub>ρ</sub> and frequency ratio d<sub>p</sub> required for pulses from the two transmitters to simultaneously reach the mixing zone and generate a sequence of scattered pulses by non-collinear interaction arriving at a receiver, and to predict the total travel time T<sub>p</sub> from the first acoustic source to a receiver through the mixing zone. Systematically scan δ and d around their predicted values, and correlate template u<sub>s</sub>(t) with the registered signal u<sub>3</sub>(t) translates into a
<img file="MX338705B_D0049.tif" />
result set M (t, δ, d) for ~ each element, receiver of arrangement 803. As discussed in previous paragraphs, the correlated signal M (t, δ, d) for each receiver element contains a band-limited peak which corresponds to nonlinear interaction in mixing zone 805 if the selection rules allow nonlinear interaction. A search is made in space for (t, δ, d) in
M (t, δ, d) to identify the location (T<sub>NL</sub>, or<sub>NL</sub>, d<sub>NL</sub>) of the band-limited peak corresponding to the nonlinear interaction in mixing zone 805, which must be in the vicinity of (T<sub>p</sub>, δ<sub>ρ</sub>, d<sub>p</sub>). The differences between (T<sub>NL</sub>, or<sub>NL</sub>, d<sub>NL</sub>) and (Tp, δ<sub>ρ</sub>, d<sub>p</sub>) are indications of deviation from the propagation velocity model from the true propagation characteristics of the rock formation. These differences are then used to update the velocity inversion propagation velocity model or other velocity update methods.
Given the relationships between frequency ratio d, ratio Vp / Vs, angle of convergence, and dispersion angle of equation 9 and figure 10, the ratio Vp / Vs of the rock formation in the mixing zone is then calculated from the value d<sub>NL</sub> observed, the angle of convergence and the angle of dispersion in the mixing zone - these last two quantities can be calculated by ray-tracing or other numerical methods from the velocity model.
<img file="MX338705B_D0050.tif" />
INST1TI »TC Μ BXICAHÍ« 7 ** ^ 5 fX PROPERTY CJ *> w »sÍW INDUSTRIAL spread updated. The amplitude value M (T<sub>NL</sub>/ §<sub>NL</sub>, d<sub>NL</sub>) contains information about the nonlinear mixing strength of the rock formation in mixing zone 805. It can be used for 3D imaging of nonlinear rock formation properties as described in the following discussion.
The ability to process non-collinear acoustic mixing signals by correlation with a template signal to identify the combination of parameters associated with a particular mixing zone, i.e. M (T<sub>NL</sub>, or<sub>NL</sub>, d<sub>NL</sub>), T<sub>NIl</sub>, 6<sub>nl</sub> yd<sub>NL</sub>, can subsequently be used for the determination of the Vp / Vs ratio, Vp and Vs propagation model and nonlinear properties is a direct consequence of the coding and correlation protocol. This unique feature influences the imaging scheme that follows.
The discussion in the paragraphs below will focus on a non-limiting example of the use of coded acoustic signals to create 3D images of the Vp / Vs ratio and nonlinear properties of the rock formation surrounding the hole. However, the use of encoded acoustic signals has broader applications beyond those related to geological and petrophysical applications including the areas of nondestructive testing and medical imaging.
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Measurement and data processing to increase the signal-to-noise ratio is described in the following paragraphs for the system described in Figure 8.
For simplicity's sake, the operating protocol is described in the context of a non-attenuating rock formation. However, the following data measurement and processing protocol may equally apply to an attenuative rock formation. The effect of attenuation on rock formation is to shift the origin of the stray wave by a predictable amount related to Q formation.
First, for a given ratio frequency ratio d of the two coded signals as described in the preceding paragraphs, the coded primary acoustic beam signals from the first acoustic power source 801 and second acoustic power source 802 of the measurement described in figure 8 are transmitted to the ground. A time delay δ is maintained between two encoded signals from source 801 and source 802. The measurement geometry honors the selection rules, and the time delay is such that the energy from the two sources reaches the mixing zone substantially simultaneously. In one embodiment, each component of the three-component geophone at receiver 8 03 at location z3
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measurement is indicated mft, δ, d, z3). Alternatively or in addition, a hydrophone may also be provided to detect a pressure signal in the return acoustic waves.
Second, the encoded primary acoustic signals are transmitted from the first and second acoustic energy sources as described in the preceding paragraphs but with reverse polarity, that is, with the phase shifted by 180 degrees. The signal recorded at receiver 803 is indicated zn_ (t, δ, d, z3).
Third, the two signals m (t, 8, d, z3) and m_ (t, δ, d, z3) are added together to form the combined signal, which can be indicated as mm (t, δ, d, z3) . Because the signals m (t, δ, d, z3) and m_ (t, δ d, z3) have opposite polarity, the signals from the linear interaction in the rock formation will be canceled by the addition of m (t, δ, d, z3) and m_ (t, δ, d, z3). However, the non-linear responses of the earth will add coherence since the amplitude of the non-linear responses is proportional to the product of the amplitudes of the two primary signals and therefore will not reverse the polarity when the polarity of both primary signals is inverted. Therefore, mm (t, 6, d, z3) would essentially contain a nonlinear interaction signal of rock formation.
Fourth, a bandpass filter of variants of
<img file="MX338705B_D0053.tif" />
time can be applied to the signal mm (t, 5, d, z3) obtained, thus maintaining a narrow band around the expected bandwidth of the signal. The bandwidth of the signal obtained is determined from the frequency differences and bandwidths of the two primary transmission signals.
Fifth, a cross correlation of the filtered signal mm (t, δ, ά, ζ3) with the template encoded signal is carried out as described in the previous paragraphs to obtain the pulsed signal that can be indicated as mmc (t, δ, d, z3).
Sixth, hodographic analysis can be applied to the three component data obtained from the three uniaxial sensors of the receiver and / or applied to the pressure signal detected by the hydrophone. These data can be used to analyze any of the possible modes P, SH and SV and can be transformed to obtain separate measurements of any of the SV, SH and P arrivals, indicated mmcr (t, δ, d, z3).
Seventh, the above six stages can be repeated several times with different encoded transmission signals and the mmcr signal collection (t, 6, d, z3) can be stacked to enhance the signal to noise. The resulting stacked signal is the signal register M (t, 5, d, z3) for each of the SV, SH and P arrivals. For example, in a P + P to SV mode,
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SV mode is detected by the receiver while it is in P + SV mode to P, the signal detected in the receiver would be in P mode.
Eighth, the above seven steps can be repeated for a sweep through a sequence of many δ and d values to obtain the complete set of M (t, δ, d, z3). The described measurement and processing protocol allows the construction of the measurement signals M (t, δ, d, z3) with high signal to noise ratio in the receiver arrangements.
Measurements M (t, δ, d, z3) can be repeated for many transmitter locations zl, z2, and many locations of receiver arrays since transmitter arrays and receiver arrays can move independently. Since the primary source acoustic beams 801 and 802 can be independently directed for any azimuth angles φΐ, φ2 and elevation angles al, a2, the measurements M (t, 5, d, z3) are also repeated for many angles φΐ, φ2, al and α2. These repeated and multiple measurements can contain several redundant signals generated by nonlinear interactions on the ground for many values of zl, z2, z3, φΐ, φ2, al and α2. Redundancy enables additional signal-to-noise increases through computer signal processing and 3D imaging of properties
<img file="MX338705B_D0055.tif" />
of rocks around the hole.
It should be noted that the steps described above for the measurement and processing protocol can be reordered or removed in various permutations as warranted. In addition, there may be many additional signal processing techniques familiar to those who are experienced with the technique of seismic signal processing, for example, multidimensional filtering, time-distance overtime analysis, and stacking. These additional techniques can be added to the data measurement and processing protocol described in the preceding paragraphs to improve the quality of the recorded data and processed images. The acoustic signal M (t, δ, d, z3) correlated from nonlinear interactions has many properties rooted in the coding methodology and selection rules.
In the following paragraphs, an imaging and workflow method that exploits these properties is described to construct 3D images of the nonlinear properties and velocity ratio Vp / Vs of a volume of land and determine other properties of such rocks. as Vp and Vs. A non-limiting example of the workflow is described below.
Referring to the measurement system described in figure 8 with trip time notations indicated in the
INSTITUI D MEXICANO
Γ> Ε THE INDUSTRIAL PROPERTY Figures 12a-12d, and the discussion in the preceding paragraphs, the correlated signal record M (t, δ, d, z3) after measurement and processing at a location of receiver z3 for a location of Particular transmitter and beam angle (zl, z2, φΐ, φ2, al and a2) will contain a band-limited peak in the travel time T = tl + t3 if the following conditions are met:
a) That the transmitted beams intersect and interact non-linearly in mixing zone 805.
b) That the time difference δ is equal to the travel time difference tl-t2.
c) That the selection rules are obeyed, that is, the frequency relation d used in the coding scheme obeys the condition of equation (19).
2-vd (19) where Vp / Vs is the ratio of compression speed to shear in the mixing zone 805 and θ is the angle of convergence between the first and second transmitted beams. The ratio Vp / Vs and angle of convergence Θ can be calculated by plotting with ray from the beam geometry, beam location and direction parameters (zl, z2, z3, φΐ, φ2, al and α2) and a model of compression rate Vp and shear rate Vs of the rock volume being
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The above conditions di-g'tan —- <r ^ the nonlinear interaction in the mixing zone 8 05 contributes to the M (t, δ, d, z3) record as a band-limited peak signal at a single point in the space (t, δ, d) for each z3 position of receiver 803. The observed location of the band-limited peak signal in register M (t, δ, d, z3) can be denoted as (T<sub>NL</sub>, 5<sub>NL</sub>, Ónl, z3). The amplitude of this band-limited peak is a function of the nonlinear interaction force, β, in mixing zone 805.
A combining process (eg, a stacking process) such as that commonly used in the seismic industry and acoustic waveform analysis of boreholes can be carried out on the M signal registers (t, δ, d, z3). The progressive time delay or distance overtime by band-limited peaks in the signal registers M (t, δ, d, z3) can be analyzed as a function of z3. For example, in a stacking process, the signal registers can be stacked to obtain a stacked register (Ms (t, δ, d, z3r) corresponding to a selected z3r reference location. The reference location is selected in such a way that the plurality of signal registers M (t, δ, d, z3) can be properly stacked. The stacking process increases the signal-to-noise ratio and improves the ability to detect location (T<sub>NL</sub>, 6<sub>NL</sub>, d<sub>NL</sub>z z3r) of the peak
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A. ... A '* i ¿- / 4.7 limited by band originating from the nonlinear interaction in the M s register (t, δ, d, z3r). Although a stacking process is described herein, other combining techniques can also be used.
Given the initial Vp and Vs velocity model, which can be estimated from the borehole well admissions and assumptions about the lateral continuity of the rock formation properties away from the auger, sound beam trajectories and travel times with elevation angle al and azimuth angle φΐ of the transmitter 8 01 in the zl position and elevation angle oc2 and azimuth angle <j> 2 of the 802 transmitter in the z2 position can be calculated by trace with lightning or other numerical modeling techniques.
Therefore, the location of mixing zone 805 can be located in space using ray tracing or other acoustic numerical modeling techniques from parameters zl, z2, z3r, φΐ, φ2, al and α2 if the beams are intersect. The predicted travel time tlp, t2p, and t3p between the locations of transmitters 801 and 802, reference receiver z3r, and mixing zone 805 can also be calculated based on position and speed using ray tracing or other acoustic numerical modeling techniques.
The predicted pulse arrival time T<sub>p</sub> = tlp + t3p and the difference in time δ<sub>ρ</sub> = tlp-t2p can be predicted from the compression rate model Vp
<img file="MX338705B_D0057.tif" />
and shear rate and then onmpar — time of arrival T<sub>NL</sub> and the difference time 6<sub>NL</sub> of the band-limited peak observed in the Ms record (t, δ, d, z3r). If the velocity model Vp and Vs correctly approximates the true velocity Vp and Vs of the rock formation, the predicted times (T<sub>p</sub>, δ<sub>ρ</sub>) are equal to the observation times (T<sub>NL</sub>, 6<sub>NL</sub>). If there are differences between the predicted times and the observed times, these differences can be used to update the velocity model Vp and Vs of propagation to minimize the differences and achieve consistency between the modeled and observed data. Various iterative speed tomographic inversion methods familiar to those skilled in the imaging technique in the seismic processing industry can be used to update the propagating Vp and Vs model.
Given the propagation model Vp and Vs obtained through the previous tomographic speed inversion stage, the acoustic beam paths with elevation angle al and azimuth angle φΐ coming from the transmitter
801 In the zl position and elevation angle ct2 and azimuth angle <¡> 2 of the 802 transmitter in the z2 position they can be calculated by ray tracing or other numerical modeling techniques. For a given azimuth angle φΐ, there will be an azimuth angle φ2 for which the origin beams are .jsTi Mexican ruro.
OE LA i'ROPISl 'Aí? k caiMU & 4®r IN DUST AIA L ^ ¿7r, intersect in a mixing zone 8 05 for which the location and angle of convergence Θ can be calculated by ray tracing or other numerical modeling techniques from the zl parameters, z2, z3r, φΐ, φ2, al and a2. The amplitude of the pulse at the point (T<sub>NL</sub>, 5<sub>NL</sub>, d<sub>NL</sub>) in the register Ms (t, δ, d, z3r) can then be assigned to the spatial coordinates of the mixing zone 8 05. Since d<sub>NL </sub>must obey equation (19), the speed ratio Vp / Vs in mixing zone 805 can be calculated from equation (19) and assigned to its spatial position. By repeating the above allocation step for a range of parameter values zl, z2, z3, ¢ 1, ¢ 2, al and α2, a 3D image of the nonlinear interaction power β and a 3D image can be constructed. of the speed ratio Vp / Vs. The velocity Vp / Vs ratio obtained from the above allocation method using selection rules is an alternative method of using the radius of the propagation velocity Vp and Vs obtained from the tomographic inversion of travel times.
The geometric mapping step described in the preceding paragraphs is just one example of many imaging techniques that can be used for 3D imaging for nonlinear property and velocity ratio Vp / Vs from signal registers M (t, δ, d, z3) for many parameter values zl, z2, φΐ, ¢ 2, al and
<img file="MX338705B_D0058.tif" />
IMPI
MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY ct2. Other advanced imaging techniques such as Kirchhoff imaging, beam imaging, wave equation imaging used in the seismic industry can be adapted for non-linear property ratio 3D imaging. and speed Vp / Vs. For example, the three-dimensional image of the compression speed Vp by propagation, the three-dimensional image of the propagation of the shear speed Vs, the three-dimensional image of the ratio of compression speed and shear speed Vp / Vs, or the three-dimensional image of nonlinear properties of a rock formation, or any combination of two or more of them can be carried out using Kirchhoff imaging, beam imaging or wave equation imaging. Furthermore, in one embodiment, the value of the propagation compression rate or the shear rate value or both can be determined using tomographic rate inversion or full waveform inversion or by iterative imaging in combination with inversion of tomographic speed or full waveform inversion.
As you can see, determining a value of a parameter can be different from imaging the parameter. In fact, an image of a parameter can only
<img file="MX338705B_D0059.tif" />
contain relative values of the parameter and do not need to provide the information about the absolute value of the parameter. Therefore, obtaining an image of the speed ratio Vp / Vs may be different from determining the value of the speed ratio Vp / Vs. Determining a speed ratio value from the speed ratio image may require additional information.
For investigation of nonlinear properties and the ratio of compression speeds to shear further in the rock formation from a hole, lower frequency sources, on the order of 500 Hz to 10 kHz, may be necessary whenever Lower frequency acoustic energy can penetrate further into the rock formations before being attenuated to an undetectable level. The lowest frequency acoustic energy on the 500 Hz to 10 kHz frequency scale has a wavelength much larger than the bore diameter. In these circumstances it is difficult to control the azimuth directions of the acoustic wave diffused from sources installed in the hole. The configuration shown in Figure 8 with two primary acoustic energy beams emanating from a hole might not be suitable for probing and imaging non-linear properties at a great distance greater than hundreds of feet from the hole. In view of this, a different low frequency system and method (500 Hz to 10 kHz) is
<img file="MX338705B_D0060.tif" />
MEXICAN INSTITUTE l> E INDUSTRIAL PROPERTY require to maximize the research distance away from the hole. The following paragraphs describe a non-limiting example of this system and method for generating three-dimensional images of nonlinear acoustic properties and velocity ratio Vp / Vs using low frequency sources. Although the following description will refer to the frequency scale from 500 Hz to 10 kHz, the described system and method may also be applicable and beneficial at higher frequency scales, for example, 10 kHz to 500 kHz.
Figure 15a shows a system of two transmitters and a receiver or receiver arrangement that are arranged in the hole to detect non-collinear mixing in a volume of rock around the hole. In one embodiment, the upper transmitter 1502 includes a linear arrangement of transmitters that can be clamped or not clamped in the hole. The lower transmitter 1501 includes a linear arrangement of transmitters that can also be clamped or non-clamped. Receiver arrangement 1502 includes a clamped three-component receiver or clamped three-component receiver arrangement. Transmitters and receivers can be moved together or independently. In one embodiment, transmitter array elements 1501 and 1502 can be arranged, for example, using a phase control, to
<img file="MX338705B_D0061.tif" />
diffuse acoustic energy into two cones — lower artistic 1504 produced by transmitter 1501 and upper acoustic cone 1505 produced by transmitter 1502), with collinear axes with transmitters 1501 and 1502. In a phase-controlled system, the cone angles depend on the phase difference between transmitting elements and the speed of the rock formation. The intersection of the two conical diffusions of acoustic energy is a torso-shaped intersecting volume 1506. When the selection rules are honest, the scattering energy 1507 is generated by the nonlinear interaction around the center of the intersecting volume 1506. The scattered energy that originates from the nonlinear interaction is recorded in the receiver or arrangement of 1508 receivers.
Because the vertical locations and elevation angles of the taper diffusions of the 1501 and 1502 transmitters are controllable, the spatial location (distance from the hole and vertical location) of your 1506 toroid intersection volume can be controlled and scanned over a volume of three-dimensional rock around hole 1500. Insofar as the convergence angles of the two cones and the frequency relationships of the two sources can be arranged to meet the selection rules, the scattered signals due to nonlinear mixing in mixing zone 1506 that are
<img file="MX338705B_D0062.tif" />
<img file="MX338705B_D0063.tif" />
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INDUSTRIAL registered in receiver 1508 contain information on the nonlinear properties of the formation at the intersection between the two cones. Data recorded by a 1508 three-component geophone array can be analyzed to determine azimuth and elevation to its origin. The signal encoding methodology described in the preceding paragraphs and the measurement and processing protocol described above can be applied to the system illustrated in Figure 15a. The correlated signal M (t, δ, d, z3) obtained from the second system and the configuration is composed of the linear superposition of all the pulses generated by the nonlinear interaction in all the intersecting volume segments 1509-1, 2, 3, etc. at 1509-k, covering the entire circumference of the toroid intersection volume 1506 as shown in Figure 15b. As described in the preceding paragraphs, the contribution of the nonlinear wave interaction by a 1509-k segment, corresponding to the interaction or mixing zone, to the resulting correlated signal M (t, δ, d, z3) at a receiver in position z3 in receiver array 1508 is a pulse with a travel time equal to the flight time from transmitter 1501 to segment 1509-k and from 1509-k to receiver if the following conditions are met:
a) that the ratio of frequency d, angle of convergence Θ and ratio of speed Vp / Vs in the segment
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INSTITUTO MÍXICANO Df THE INDUSTRIAL PROPERTY particular 1506-k obeys the selection rule condition of equation (19),
b) that the time delay δ between the encoded source transmitter signals is equal to the difference between the flight times of the transmitter 1501 to 1509-k and the transmitter 1502 to 1509-k.
In other words, the pulses generated by non-linear mixing in the intersecting volume segments 1509-1 to 1509-k in the correlated signal M (t, δ, d, z3) are distributed over an interval of (t, δ, d) for each receiver at position z3. The contribution of each 1509-k segment can be assigned to a point in space (t, δ, d) on the correlated signal M (t, δ, d, z3). This property, together with the signal path information obtained from the three-component receivers, allows the geometric assignment of the signal amplitude at the point (t, δ, d) in the correlated signal M (t, δ, d, z3) to the spatial locations of the intersecting volume segments 1509-1 through 1509-k within the toroidal intersecting volume using the imaging methods described in the preceding paragraphs. An initial Vp and Vs propagation model is constructed. Ray tracing, travel time analysis, and iterative tomographic velocity determination are then performed to obtain an updated Vp and Vs propagation model. The properties
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OF THE i * kOR | R |,<sub>TO</sub>, j INDUSTRIAL
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Nonlinear and velocity ratios Vp / Vs in segments 1509-1 to 1509-k in the toroid intersection volume can then be extracted and assigned to spatial locations in the toroid intersection volume using ray tracing analysis applied to the model. Vp and Vs updated using the workflow described in the previous paragraphs. By repeating measurements for all conical transmission elevation angles and vertical locations in the transmitter bore, images of nonlinear properties and velocity ratio Vp / Vs can be constructed for all mixing zones surrounding the bore. The images for all the scanned mixing zones can then be combined to produce a full 3D image of non-linear properties and Vp / Vs velocity ratio using a suitable processing method known to those skilled in the imaging technique. seismic such as, for example, the weighted stacking method, of all images.
The system and method using low frequency conical acoustic diffusions for a vertical well can work well when the rock volume does not have azimuth symmetry. However, if the rock volume has a very high degree of azimuth symmetry for the propagation velocities Vp and Vs and therefore by implication its velocity ratio Vp / Vs, this system can find
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of the pftoritDAi) ¢ - .., 9: *>, '·. INDUSTRIAL ** <_ £ 'LrS ·' some difficulties in solving azimuth variations in formation properties and generating 3D images. Referring to Figure 15b, nonlinear signals generated by nonlinear interaction from segments' 1509-1 to 1509-k in the toroid intersection volume arrive simultaneously at each receiver when there is full azimuth symmetry. In this case, it would be difficult to separate the pulses originating from various segments 1509-1 to 1509-K in the toroid intersection volume since these occur at the same time in the correlated signal M. This introduces ambiguity in the exercise of assignment. The above constraint can be avoided if a hole or hole system is designed to overcome limitations due to azimuth symmetry. In the following paragraphs, a non-limiting measurement system and method that uses various drill configurations designed to achieve this goal will be described.
Figures 16a and 16b show an example of a non-collinear mixing arrangement with receiver arrangement 1603 located in a straight section of the bore and transmitter centers 1601 and 1602 located on the extended axis 1625 of the receiver arrangement. In the case of linear phase arrangements, transmitters diffuse acoustic energy into 1604 and 1605 cones with shafts aligned with the transmitter arrangements. The cones and their locus of
<img file="MX338705B_D0065.tif" />
IMPI
MEXICANC INSTITUTE
I »IA i'RCIRIROAO INDUSTRIAL intersection 16 07 are illustrated in Figures 16a and 16b, in accordance with aspects of the present invention. As shown in Figure 16a, the intersection locus can be thought of as a series of adjacent intersecting volume segments, 1608-k, where k = K, four of which are identified as 1608a, 1608b, 1608c, and 1608d . From a geometric analysis it can be shown that if two intersecting volume segments have the same convergence angles, their corresponding flight time differences (from lower and upper transmitter to the intersecting volume segment) tl-t2 are different. Two locations on opposite sides of the intersection locus corresponding to the mixing zones, with similar convergence angles and velocity ratio Vp / Vs, can therefore be activated individually by controlling the frequency ratio d and the time delay δ between diffusions encoded from the two transmitters. Similarly, two hours of mixing with the same flight time difference tl-t2 have different angles of convergence Θ, so an acoustic signal arriving simultaneously in two mixing segments could only meet the selection rule requirements for a ratio velocity Vp / Vs, frequency relation d and angle of convergence θ in one of the two locations.
As can be seen from the paragraphs
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MEXICAN INSTITUTE OF PROMNAL · INDUSTRIAL * ¿f ^ »
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* ¿Above, the intersection of two conical acoustic Hifnsionogs defines an intersection volume in the form of a toroid. For the purposes of the present invention, a toroid is defined as an annular shape that is generated by stirring a flat geometric shape such as a polygon, circle, ellipse, or other shape to define a closed volume. In one embodiment, the toroid may be an annular torus or O-ring where the flat geometric shape or cross shape is a circle that revolves around an axis. In another embodiment, the toroid can be defined as a polygonal shape that is elliptically stirred to form a closed volume. The toroidal volume can be segmented into a plurality of intersecting volume segments. Depending on the non-linear selection rules and a judicious selection of various parameters including a difference in start time and frequency ratio between the diffused acoustic signals, one or more intersecting volume segments can be activated to provide one or more mixing zones when the two conical transmission signals interact nonlinearly within the mixing zones to generate a signal that is representative of the nonlinear properties of the rock formation in that area.
The coding methods described in the previous paragraphs, the measurement protocols and
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INDUSTRIAL processing described in the preceding paragraphs imaging methods described in the preceding paragraphs can be applied to the measurement system illustrated in Figures 16a and 16b. The applications follow the general approach described in the previous paragraphs. Unlike the straight hole configuration in Figure 15, there is no aspect of simultaneous arrivals in the space of (t, δ, d). Thus, the measurement system described in Figure 16 that uses a bore with an intentionally bent path would be more robust for general 3D imaging of nonlinear properties and velocity ratio Vp / Vs. A by-product of the imaging method is the Vp and Vs propagation model generated by tomographic speed inversion of the intermediate stage of the imaging process.
It should be noted that the absence of azimuth symmetry in the configuration of the curved or angled hole path and inclined conical acoustic wave transmission as shown in Figure 16 can also be achieved on a smaller scale by shifting the angles of transmitter arrangements smaller within a single hole, or by a similar configuration on a wireline or pipeline and a logging tool carried on a wireline or pipeline, etc.
Figures 17a and 17b show two examples
<img file="MX338705B_D0068.tif" />
<img file="MX338705B_D0069.tif" />
Additional IMPIs of transceiver arrangements within various cone angle and axial orientation bore configurations that can be used for 3D velocity ratio imaging Vp / Vs and nonlinear properties of surrounding rock formation the hole. Figure 17a shows an example of a single well arrangement with an angled hole where there is a complete intersection of the lower cone within the upper cone. For example, as shown in Figure 17a, the upper transmitter 1702 is arranged to produce a wider cone of acoustic energy 17 05 than the narrower cone 17 04 produced by the lower transmitter 1701, such that there is a complete intersection. from the lower cone into the upper cone. Both transmitters 1701 and 1702 are placed in hole 1706, while receiver 1703 is placed in main vertical hole 1700. As in the configurations of Figures 15 and 16a-16d, transmitters 1701 and 1702 can be arranged as an arrangement, for example a linear arrangement, of acoustic dot sources in a hole. The acoustic energy generated by transmitters 1701 and 1702 interacts with the nonlinear material in the intersection zone, and acoustic energy is received at receiver 1703 in accordance with the selection rules, as described above. The nonlinear mixing zone includes a locus of intersection 1709 between cones 1704 and 1705 that spans
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INDUSTRIAL —__ one point closest 17 07 to hole 17 00 and one point furthest 1708 from hole 1700.
Figure 17b shows another example of a single well arrangement with a severely angled hole with a lower transmitter emission energy almost perpendicular to the axis of the 1700 hole. In these configurations, the intersection between the cones is a hyperbola, not an ellipse. as in the previous examples. However, similar measurements, coding, data processing, and imaging protocols still apply. Also, because the intersection between the cones is not a closed curve, the depth of investigation is determined by the strength of the source, receiver sensitivity, and the effectiveness of signal processing algorithms.
One difference between a configuration that results in a closed elliptical intersection locus with a configuration that results in a parabolic open curve locus is that at a closed elliptical intersection locus a frequency ratio scan can start at a low frequency ratio f2 / fl (see, for example, figure 10b) which corresponds to a higher angle of convergence than that at the nearest point. The frequency ratio f2 / fl can then be increased, for example, until the nearest point on the ellipse is activated. The
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Scanning can be continued until the furthest intersection point is reached. By further increasing the frequency ratio f2 / fl, no signal would be received because no zone would be activated. On the other hand, if the intersection is an open curve, the f2 / fl frequency ratio can be scanned starting at the closest point and continuing until the return signals to the receiver from either side of the hyperbola become undetectable.
Figure 18a shows an example of a vertical well and side rail with receivers in the vertical part of the well. Figure 18b shows another example of a vertical pilot hole and horizontal side rail with receivers in the side rail in accordance with aspects of the present invention. The main vertical hole 1800 includes a transmitter 1801 arranged to produce a vertical cone of acoustic energy 1804, while the side rail hole 1806 includes a transmitter 1802 arranged to produce an acoustic cone 1805. Receiver 1803 can be arranged either in the hole main vertical 1800 as in figure 18a, side rail hole 1806 or both main hole 1800 and side rail hole 1806 depending on the particular application used. As in the examples of Figures 17a to 17c, transmitters 1801 and 1802 and receiver 1803 may include an arrangement of transmitters and receivers, respectively. The transmitter
02 in the lane hole above or below the 1800 main transmitter.
side
1801 in
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1806 can be located in the vertical hole
Although the configurations in Figures 17a through 17b, 18a, and 17b differ somewhat in complexity from drilling and operating perspectives, there are many benefits to using different configurations including the ability to perform deeper remote sensing from the auger by maximizing the distance to the intersection of the two cones. Additionally, transmitters that generate acoustic energy in a direction close perpendicular to the hole can provide more power and more angular resolution for scans defined by smaller cone angles. It should be noted that the figures above are only examples of configurations of using a multitude of possible hole configurations. As can be appreciated, there may be many other drill configurations that also allow the placement of the two primary acoustic arrangements at different azimuth angles and elevation angles.
The techniques described above, a combination of invoking the signal selection and encoding rules, can be used to scan and create images of a volume defined by two intersecting cones formed by the acoustic energy coming from the two transmitters, some
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SO away from the hole. The previous dissent destroyed the P + P ^ SV interaction. However, other allowed interactions can also be used in a similar way with the examples shown in Table 1.
As can be seen from the preceding paragraphs, various methods of investigating a rock formation can be implemented with a system for sounding planning, data acquisition and storage, and image processing and interpretation. Figure 19 illustrates a system for sounding planning, data acquisition and storage, and image processing and interpretation, in accordance with one embodiment of the present invention. In one embodiment, the system can generate 3D images of nonlinearity properties, velocity ratio Vp / Vs, and propagation compression and shear rate of a cylindrical volume of rock formation, centered on the hole. In one embodiment, 3D nonlinearity and velocity ratio Vp / Vs images can include nonlinearity and velocity ratio Vp / Vs images extending outward to a research radius of several hundred meters, for example.
In one embodiment, the system can be viewed as a suite of hardware and / or software or module subsystems. The 1900 to 1904 subsystems are used for probing planning and execution, transmission of
<img file="MX338705B_D0071.tif" />
perforations, coding and transmission of the transmitted acoustic waves and recording and detection of the non-linear signal. The 1901 and 1905 subsystems are used for image processing after soundings. The 1900 subsystem is used for sounding design, data design acquisition, monitoring, and recording. The 1901 subsystem is used for information on preliminary nonlinearity and velocity images. The 1902 subsystem is used for receiver and sensor transmission and control. The 1902 subsystem is configured to emit controlled acoustic broadcasts and receive acoustic energy. The 1903 subsystem is used to generate a transmit signal. The 1904 subsystem is used for detection of nonlinear signals. The 1905 subsystem is used to image non-linearity and imaging speed.
In one embodiment, subsystem 1900 includes modeling for 1907 acquisition module, 1908 data acquisition controller, 1930 data enhancement and pre-processing module, and 1921 data storage device. In one embodiment, subsystem 1901 includes initial velocity model module 1906 and 1981 module for preliminary three-dimensional imaging including propagation shear and compression velocity images, Vp / Vs velocity ratio images, and nonlinearity images that are associated with amplitudes
<img file="MX338705B_D0072.tif" />
of the measured signal that originates from the non-linear integer flow into the mixing zone. In one embodiment, the 1902 subsystem includes the 1909 tool installation and transport module, the 1910 mechanical tool controller, the 1917 azimuth and elevation controller for controlling the azimuth and elevation angles of the first acoustic source (SI), and azimuth controller and elevation 1918 to control the azimuth and elevation angles of the second sound source (S2). In one embodiment, subsystem 1903 includes coded signal generator 1911, frequency multiplier and time delay module 1912, signal amplifier 1913 for generating the signal sent to the first acoustic source (SI), signal amplifier 1914 for generating the signal sent to the second acoustic source (S2). In a
<td>modality, the</td><td>subsystem 1904</td><td>It includes</td><td>modules</td><td colspan="2">receivers</td><td> 1922</td>
<td>to receive</td><td colspan="3">u3 (t) signals from receivers</td><td>Rl,</td><td>R2, ...,</td><td>Rn,</td>
<td>modules</td><td>increase of</td><td>signal</td><td colspan="2">nonlinear</td><td> 1924</td><td>for</td>
increasing the signal received by the signal receiving modules 1922, a template signal generator module 1927 to generate a template signal u<sub>s</sub> (t), and a 1928 signal correlation module to correlate signal u<sub>3</sub> (t) with the template signal u<sub>s</sub>(t), as described in the preceding paragraphs. In one embodiment, the 1905 subsystem includes the 1932 pre-processing and data enhancement module, the 1933 velocity model iteration module, the
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INDUSTRIAL imaging iteration 1934, 1936 output imaging module for speed ratio images and / or nonlinearity images, and 1935 output speed modules for sending determined values of velocities Vp, velocity Vs, and / or ratio of speed Vp / Vs.
As can be appreciated, the term module is used herein to encompass a hardware device, a software program, or both. For example, the image iteration module can be a piece of hardware that is configured to perform the iteration, or a software program that can be run on a computer to carry out the iteration, or it includes both a piece of hardware and a software application.
In operation, prior to data acquisition, slow compression and shear records and information about lateral continuity formation can be used - to construct an initial layered earth model that extends laterally away from the hole using the 1906 module. The 1906 Module Initial Rate Model is used by a 1907 Forward Modeling Acquisition Module to provide a data acquisition plan that an operator uses to program the 1908 Data Acquisition Controller using operator inputs.
After the 1902 subsystem is installed in the hole through the installation and transport module
<img file="MX338705B_D0073.tif" />
Tool 1909 and attached by the mechanical tool controller 1910 to the hole wall if required, input commands can be sent to the 1903 coded signal generator subsystem where coded pulse sequences are generated by the coded signal generator module 1911. The encoded signals generated by the encoded signal generator module 1911 are frequency adjusted and delayed by the frequency multiplier and time delay module 1912 such that the signal amplifiers 1913 and 1914 provide signals to SI 1915 and S2 transmitters or sources. 1916 to broadcast the signals in a delayed manner such that the signals from SI and S2 simultaneously reach the mixing zone, as illustrated, for example, in figure 12a.
The geometry of the broadcasts including the elevation and azimuth angles of the acoustic broadcasts of the SI 1915 and S2 1916 sources is controlled by commands from the 1908 data acquisition controller that sends angle control commands to azimuth angle controllers and elevation 1917 and 1918 of hole. All data pertaining to tool configuration and transmission geometry collected from 1909 tool installation, 1910 mechanical tool controller, 1917 and 1918 elevation and azimuth controllers listed in
<img file="MX338705B_D0074.tif" />
the present as adqn-ί si ri ón_-register parameters 1919 are the registered data storage device 1921. Similarly, the encoding scheme from the encoded signal generated subsystem 1903 indicated herein as transmission information of registration in 1920 is also recorded in the storage device. data 1921.
In one embodiment, signals from signal modules 1922 registered to receiver or receivers 1923 (eg, each of the receivers may have for example hydrophones, 3-component geophones, or both R1 to Rn) can be processed by the 1924 non-linear signal increment to increase non-linear source content and substantially reduce or suppress linear interaction source signals or potential noise. Raw signals indicated in 1925 from the signal receiving modules 1922 and incremental signals indicated in 1921 are stored in the data storage device 1921. A template signal u<sub>s</sub>(t) generated by the template signal generator 1927, which can be derived from the Ui signals (t) generated by the signal generators 1912 and the frequency multiplier and time delay module 1912, are correlated with signals received indicated by 1925 in 1928, as described for example in Figures 12 to 14. The correlation of the template signal u<sub>s</sub>(t) and
<img file="MX338705B_D0075.tif" />
signal received or detected u<sub>3</sub>(t) is used to extract by means of the correlated signal output module 1929 a correlated signal M (t, d, δ, z3). The correlated signal is also stored in data storage device 1921.
In one embodiment, the data acquisition process implemented using components or modules 1909 to 1929 can be repeated with different beam geometries or at various locations (z3) within the well. In one embodiment, previously recorded data can be used to guide changes in acquisition parameters. For example, data stored within storage device 1921 can be further increased, for example, by module-based analysis of hodographic analysis and 1930's hodographic pre-processing. The data stored in the storage device 1921 can further be used in conjunction with an initial velocity model from the initial velocity model module 1906 to create a set of images of nonlinear properties and / or Vp / Vs relationships with modulus of 1931 imaging. These can be used to refine modeling by the 1907 acquisition design module and / or acquisition parameters controlled by the 1908 data acquisition controller.
After the probing is complete, additional data processing can be implemented by means of the 1932 Pre-Processing and Data Enhancement module.
<img file="MX338705B_D0076.tif" />
IMPI
INSTITUTO MEXICANO OF LA PROPIfOAIT INDUSTRIAL modality, hodographic analysis can be conducted to precondition the data for final analysis. The initial velocity model in module 1906 and 1931 module images can be used as a starting point for further iteration of the velocity model through the 1933 velocity model iteration module and non-linear property imaging iteration and / or Vp / Vs relationship through imaging iteration between 1933 velocity modeling module and 1934 imaging module. The end result of the iteration is an optimized velocity model sent through the 1935 output module and images including Vp / Vs ratio images and / or images of non-linear properties sent through the 1936 output module.
In one embodiment, the above implementation of the system is suitable for imaging outwards at relatively large distances from the hole (for example, up to several hundred meters) and includes components designed to maximize signal-to-noise ratio and detection of weak signals from of a complex petrophysical, stratigraphic and structural context. Applications near the hole that probe a smaller volume with less variation in properties and more powerful returned signals could potentially eliminate some aspects or portions or modules of the system involved with signal detection and iteration of
IMPI
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speed models. Also, in a less demanding acquisition environment, some aspects of hardware could be simplified, for example clamped three-component geophones could be replaced with non-directional hydrophone receivers mounted on a centralized probe.
Furthermore, as can be appreciated, although the system was described above as linking the acquisition data portion of the system to the imaging portion of the system, the acquisition of the data portion can be accomplished separately from the imaging. of Vp / Vs ratio and / or nonlinear properties. In fact, the acquired data can be achieved by a first entity and the data stored in the data storage device 1921. The data acquired in the data storage device 1921 can then be transferred to a second entity, which may be the same or different from the first entity, the second entity may use the described imaging subsystem or imaging method in the previous paragraphs to obtain the images of Vp / Vs and non-linear properties.
Furthermore, although each module is described in the previous paragraph as having specific functionality, as you can see any functionality in one or more modules can be moved to any one or more different modules. For example, some or all of the functionality in the subsystem
<img file="MX338705B_D0078.tif" />
UVA 190 1903 encoded signal generator can be moved to 1904 non-linear signal detection subsystem.
Furthermore, it should be appreciated that the term processor is used herein to encompass one or more processors. The one or more processors can be configured to implement the methods or portions of the methods described herein. The one or more processors may be located on one or more computers such as, for example, in a distributed computing environment. In some embodiments, programs for carrying out methods in accordance with embodiments of the invention may be incorporated as program products in a computer such as a personal computer or server or in a distributed computing environment comprising a plurality of computers. When referring to a processor, that term should be understood to encompass any of those computing provisions. The computer may include, for example, a desktop computer, a personal computer, a manual computing device. Computer program products may include a computer readable medium or storage medium or media having instructions stored therein used to program a computer to carry out the methods described above. Examples of suitable storage media or media include any type of disc including floppy discs, optical discs, DVDs, CD ROMSs,
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INDUSTRIAL optical magnetic disks, RAMs, EPROMs, EEPROMs, magnetic or optical cards, hard disk, flash card (for example, a USB flash card), PCMCIA memory card, smart card or other media. Alternatively, a portion or all of the computer program product may be downloaded from a remote computer or server over a network such as the Internet, an ATM network, a wide area network (WAN), or a local area network.
Although the invention has been described in detail for purposes of illustration based on what is currently considered to be the most practical and preferred embodiments, it should be understood that this detail is for that purpose only and that the invention is not limited to the embodiments. described, but, on the contrary, is intended to cover equivalent modifications and provisions that are within the spirit and scope of the appended claims. As a further example, it should be understood that the present invention contemplates that, to the extent possible, one or more features of any one embodiment may be combined with one or more features of any other embodiment.
<td></td><td>I know</td><td>states that</td><td>in relation to this date,</td><td>the</td>
<td colspan="2">best method</td><td>known for the</td><td>applicant to carry</td><td>the</td>
<td>practice</td><td>the</td><td>cited invention,</td><td>is the one that is clear from</td><td>the</td>
present description of the invention.
Contents54
97 sheets
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186 members in 30 offices
Priority claims7
| Document | Office | Kind | Date |
|---|---|---|---|
| 41317310 | United States of America | P | |
| 61413173 | United States of America | – | |
| 2011059967 | United States of America | W | |
| 61413173 | – | – | – |
| US1159967 | – | – | – |
| US20100413173P | – | – | – |
| WO2011US59967 | – | – | – |
Members186
| Document | Office | Kind | |
|---|---|---|---|
| CA2790412A1 | Canada | A1 | |
| CA3014767A1 | Canada | A1 | |
| CA3206109A1 | Canada | A1 | |
| WO2011106528A1 | World Intellectual Property Organization (WIPO) | A1 | |
| TW201138816A | Taiwan Province of China | A | |
| US2012009181A1 | United States of America | A1 | |
| AR080301A1 | Argentina | A1 | |
| US2012120761A1 | United States of America | A1 | |
| US2012120763A1 | United States of America | A1 | |
| US2012120764A1 | United States of America | A1 | |
| US2012120765A1 | United States of America | A1 | |
| US2012120766A1 | United States of America | A1 | |
| US2012120767A1 | United States of America | A1 | |
| US2012123684A1 | United States of America | A1 | |
| CA2817532A1 | Canada | A1 | |
| CA2817561A1 | Canada | A1 | |
| WO2012064839A2 | World Intellectual Property Organization (WIPO) | A2 | |
| WO2012064842A2 | World Intellectual Property Organization (WIPO) | A2 | |
| AU2011220728A1 | Australia | A1 | |
| SG183144A1 | Singapore | A1 | |
| IL221241A0 | Israel | A0 | |
| IL221241D0 | Israel | D0 | |
| MX2012009754A | Mexico | A | |
| EP2538976A1 | European Patent Office (EPO) | A1 | |
| KR20130012117A | Republic of Korea | A | |
| CN103037900A | China | A | |
| AU2011326567A1 | Australia | A1 | |
| AU2011326570A1 | Australia | A1 | |
| WO2012064842A3 | World Intellectual Property Organization (WIPO) | A3 | |
| JP2013524773A | Japan | A | |
| WO2012064839A3 | World Intellectual Property Organization (WIPO) | A3 | |
| SG190251A1 | Singapore | A1 | |
| MX2013005333A | Mexico | A | |
| EP2538976A4 | European Patent Office (EPO) | A4 | |
| SG190791A1 | Singapore | A1 | |
| MX2013005146A | Mexico | A | |
| CN103282795A | China | A | |
| EP2637693A2 | European Patent Office (EPO) | A2 | |
| EP2638415A2 | European Patent Office (EPO) | A2 | |
| CN103329008A | China | A | |
| US8557966B2 | United States of America | B2 | |
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| EA201390693A1 | Eurasian Patent Organization (EAPO) | A1 | |
| EA201390696A1 | Eurasian Patent Organization (EAPO) | A1 | |
| JP2014500961A | Japan | A | |
| JP2014506317A | Japan | A | |
| RU2012135395A | Russian Federation | A | |
| NZ601617A | New Zealand | A | |
| AU2011326567B2 | Australia | B2 | |
| AU2011220728B2 | Australia | B2 | |
| AU2014213540A1 | Australia | A1 | |
| EA201390696A8 | Eurasian Patent Organization (EAPO) | A8 | |
| US8923092B2 | United States of America | B2 | |
| US8942063B2 | United States of America | B2 | |
| KR20150031488A | Republic of Korea | A | |
| SG10201501342UA | Singapore | A | |
| US9046620B2 | United States of America | B2 | |
| NZ621938A | New Zealand | A | |
| AU2011326570B2 | Australia | B2 | |
| US9110178B2 | United States of America | B2 | |
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| AU2011326570C1 | Australia | C1 | |
| KR101580713B1 | Republic of Korea | B1 | |
| US9223039B2 | United States of America | B2 | |
| SG10201509344RA | Singapore | A | |
| JP2016000729A | Japan | A | |
| UA110783C2 | Ukraine | C2 | |
| TW201607555A | Taiwan Province of China | A | |
| US2016060339A1 | United States of America | A1 | |
| US2016075781A1 | United States of America | A1 | |
| US2016083471A1 | United States of America | A1 | |
| CN103037900B | China | B | |
| US2016096887A1 | United States of America | A1 | |
| US2016096888A1 | United States of America | A1 | |
| MX338705BThis record | Mexico | B | |
| KR101637138B1 | Republic of Korea | B1 | |
| MX340437B | Mexico | B | |
| KR20160083962A | Republic of Korea | A | |
| CN105777907A | China | A | |
| BR112013011863A2 | Brazil | A2 | |
| BR112013011870A2 | Brazil | A2 | |
| JP2016153412A | Japan | A | |
| US9453926B2 | United States of America | B2 | |
| SG10201606573SA | Singapore | A | |
| NZ709390A | New Zealand | A | |
| EP2538976B1 | European Patent Office (EPO) | B1 | |
| JP6039751B2 | Japan | B2 | |
| AU2016265966A1 | Australia | A1 | |
| MX345001B | Mexico | B | |
| RU2610663C2 | Russian Federation | C2 | |
| DK2538976T3 | Denmark | T3 | |
| MX346092B | Mexico | B | |
| PT2538976T | Portugal | T | |
| US9598490B2 | United States of America | B2 | |
| LT2538976T | Lithuania | T | |
| HRP20170281T1 | Croatia | T1 | |
| US9657100B2 | United States of America | B2 |
Numbers
- Publication
- 338705
- Publication, DOCDB
- 338705
- Publication, EPODOC
- MX338705
- Application
- 2015008273
- Application, DOCDB
- 2015008273
- Application, EPODOC
- MX20150008273
Titles
- Spanish
- SISTEMA Y METODO PARA INVESTIGAR CARACTERISTICAS SUBSUPERFICIALES DE UNA FORMACION DE ROCA.
Classification
- CPC, 10
- G01V1/006
- A61P35/00
- G01V1/46
- G01V2210/125
- G01V2210/127
- G01V2210/588
- G10K15/02
- G01V1/44
- G01V1/50
- G01V1/52
- IPC, 1
- G01V1 40