Measurement and control of asphaltene agglomeration in hydrocarbon liquids
Abstract
A method for measuring the agglomeration state of asphaltenes in asphaltene-containing oil, which comprises - application of an acoustic energy signal to the oil, thereby diffusing at least part of the energy; - detection of diffused acoustic energy over a selected frequency range; - resolution of the magnitude of the diffused acoustic energy detected at the selected frequencies within the selected frequency range; - determination of the state of agglomeration of asphaltenes comparing the magnitude vs. frequency data with a standard.

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26 claims: 1 independent, 25 dependent
- 1ES 2 272 011 T3 REIVINDICACIONES 1. Un método para medir el estado de aglomeración de los asfaltenos en el petróleo que contiene asfaltenos, que comprende - aplicación al petróleo de una señal de energía acústica, difundiendo de este modo al menos una parte de la energía;- detección de la energía acústica difundida sobre un rango de frecuencias seleccionado;- resolución de la magnitud de la energía acústica difundida detectada en las frecuencias seleccionadas dentro del rango de frecuencias seleccionado;- determinación del estado de aglomeración de los asfaltenos comparando los datos de magnitud vs frecuencia con un estándar.
- 2Un método como el expuesto en la reivindicación 1 en el cual las frecuencias seleccionadas dentro del rango de frecuencias seleccionado comprende al menos tres frecuencias diferentes.
- 3Un método como el expuesto en la reivindicación 1 en el cual las frecuencias seleccionadas dentro del rango de frecuencias seleccionado comprende al menos quince frecuencias diferentes.
- 4Un método como el expuesto en la reivindicación 1 en el cual las etapas se llevan a cabo sin diluir el hidrocarburo líquido.
- 5Un método como el expuesto en la reivindicación 4 en el cual las etapas del mismo se efectúan en menos de un segundo.
- 6Un método como el expuesto en la reivindicación 5, en el cual la energía acústica difundida detectada es una energía acústica retro-difundida.
- 7Un método como el expuesto en la reivindicación 6, en el cual el rango de frecuencias seleccionado es de 0.1 MHz a 200 MHz.
- 8Un método como el expuesto en la reivindicación 7, en el cual el rango de frecuencias seleccionado es de 0.1 MHz a 20 MHz.
- 9Un método como el expuesto en la reivindicación 8, en el cual el rango de frecuencias seleccionado es de 14 MHz a 20 MHz.
- 10Un método como el expuesto en la reivindicación 1, en el cual la detección se lleva a cabo por al menos un sensor el cual se incorpora a una sonda de entrada de la señal.
- 11Un método como el expuesto en la reivindicación 1, en el cual la detección se lleva a cabo por al menos un sensor el cual está separado de una sonda de la entrada de la señal.
- 12Un método como el expuesto en la reivindicación 11, en el cual la sonda de entrada de la señal y el sensor se localizan para que la dirección de la señal de la sonda se intersecte con la dirección de la señal del sensor a un ángulo menor de 90°
- 13Un método como el expuesto en la reivindicación 12, en el cual la sonda de entrada de la señal y el sensor se sitúan de tal forma que la dirección de la señal de la sonda se intersecte con la dirección de la señal del sensor a un ángulo menor de 60°.
- 14Un método como el expuesto en la reivindicación 13, en el cual la sonda de entrada de la señal y el sensor se sitúan de tal forma que la dirección de la señal de la sonda se intersecte con la dirección de la señal del sensor a un ángulo menor de 45°.
- 15Un método como el expuesto en la reivindicación 1, en el cual la señal de energía acústica se aplica bajo la forma de un pulso y la etapa de resolución de la magnitud de la energía acústica difundida detectada a las frecuencias seleccionadas dentro del rango de frecuencia seleccionado comprende la activación del circuito puerta de la energía acústica difundida detectada a esa parte de la energía detectada que emana de una región focal y la transformación de Fourier de la energía difundida detectada en un formato de magnitud vs frecuencia.
- 16Un método como el expuesto en la reivindicación 1, en el cual la señal de la energía acústica se aplica como una ráfaga de tonos y la etapa de resolución de la magnitud de la energía acústica difundida detectada en las frecuencias seleccionadas dentro del rango de frecuencias seleccionado comprende la detección de la magnitud de la energía difundida en las frecuencias seleccionadas dentro del rango de frecuencias seleccionado. ES 2 272 011 T3
- 17Un método como el expuesto en la reivindicación 1, en el cual la determinación del estado de aglomeración de los asfaltenos se efectúa comparando la distribución de las partículas de asfalteno que difunden la energía acústica dentro del rango de frecuencias seleccionado con un estándar.
- 18Un método como el expuesto en la reivindicación 17, en el cual el estándar es una muestra de tamaño de partícula conocido.
- 19Un método como el expuesto en la reivindicación 17, en el cual el estándar es un modelo de tamaño de partícula basado en la teoría de la difusión.
- 20Un método como el expuesto en la reivindicación 1, en el cual el petróleo que contiene los asfaltenos se encuentra en una corriente de flujo del proceso y la señal de energía acústica se aplica al petróleo en la corriente del flujo de proceso.
- 21Un método como el expuesto en la reivindicación 1 que comprende las etapas de:a. remoción de una muestra del petróleo y sin diluirlo;b. aplicación al petróleo dicha señal de energía acústica, difundiendo de este modo al menos una parte de la energía;c. detección de la magnitud de la energía acústica difundida sobre un rango de frecuencias seleccionado;d. resolución de la magnitud de la energía acústica difundida detectada a incrementos seleccionados dentro del rango de frecuencias seleccionado;e. derivación de tal resolución una distribución del tamaño relativo de partículas de asfalteno que difunden la energía acústica dentro del rango de frecuencias seleccionado;y f. determinación del estado de aglomeración de las partículas de asfalteno.
- 22Un método como el expuesto en la reivindicación 21, que presenta la etapa adicional de retornar la muestra de petróleo no diluida.
- 23Un método como el expuesto en la reivindicación 21, en el cual el método se lleva a cabo en un dispositivo a pequeña escala.
- 24Un método para controlar la aglomeración de los asfaltenos en petróleo, el cual comprende la realización del método de la reivindicación 1, comparando la energía resuelta difundida detectada con un estándar, y actuar de manera que se controle el número de partículas que tiene un tamaño de partículas correspondiente a las frecuencias incrementales seleccionadas.
- 25Un método como el expuesto en la reivindicación 24, en el cual el rango de frecuencias seleccionado para detectar la energía acústica difundida se limita a un rango de frecuencias de energía acústica difundida por las partículas de asfalteno aglomeradas características del petróleo.
- 26Un método como el expuesto en la reivindicación 24, en el cual el rango de frecuencias seleccionado es de 14 MHz a 20 MHz.
Independent claims26
119 paragraphs in 8 sections, as filed
ES 2 272 011 T3
DESCRIPTION
Measurement and control of asphalt agglomeration in liquid hydrocarbons.
Background of the invention (1) Field of the invention
The present invention relates to the measurement and / or control of the agglomeration of asphaltenes in liquid hydrocarbons.
(2) Description to related art
Asphaltenes are organic heterocyclic macromolecules found in crude oil. Under normal reservoir conditions, asphaltenes are usually stabilized in the crude oil dispersion by maltenes and resins that are chemically compatible with asphaltenes, but have a much lower molecular weight. The polar regions of the maltenes and resins surround the asphaltenes while the non-polar regions are attracted to the oil phase. In this way, these molecules act as surfactants and lead to the stabilization of asphaltenes in crude oil. However, changes in pressure, temperature, or concentration of crude oil can alter dispersion stability and increase the tendency of asphaltenes to agglomerate into larger particles. As these asphaltene agglomerates grow, their tendency to precipitate also increases.
Precipitation of asphaltenes in crude oil or in process oil streams is economically costly due to the loss of productivity and the maintenance required to remove blockages caused by solid materials.
Various methods have been devised to minimize asphaltene precipitation. For example, pressure and temperature conditions can be maintained, chemical stabilizers added to mimic and increase the stabilizing effect of natural resins and maltenes, or devices such as the magnetic flux assemblies described in US Patent No. 5,453,188 can be used. . While methods that minimize asphaltene precipitation can lead to significant savings, they have been hampered by the lack of a method to measure and track the agglomeration state of asphaltenes in a particular stream, at a particular time. Without knowing the agglomeration state of the asphaltenes in the stream, it is unclear when or in what amount the liquids should be treated to prevent asphaltene precipitation.
Conventional methods for determining the size and concentration of asphaltene particles in hydrocarbons, such as those described in US Patent No. 4,238,451 or Standard Method IP 143/84, require sampling, transport to a laboratory, and precipitation tests. and filtration, centrifugation, titration with a destabilizing solvent or other lengthy techniques concerned. Thus, these methods are time consuming and destructive of used samples when used on a small scale or in laboratory setups and are not suitable for tracking agglomeration in real time or online.
Although methods for analyzing particle size and concentration in optimally clear streams have been modified and applied to hydrocarbons, many have been much less successful in crude oil and other in-process oil streams due to contamination and opacity. . For example, the optical system of Yamazoe, et al., US Pat. Do not. 4,843,247, measures the asphaltene content, but provides a flushing means to remove the sample solution from the optical probes each time a sample measurement is performed. Such washing requires more comprehensive measurement devices and infers that contamination can hamper the accuracy of the optical measurement over time.
Direct centrifugation of crude oil measures the total amount of asphaltene present, but does not provide information on the size and degree of agglomeration of the particles or their tendency to remain in a stable dispersion.
Recently non-optical tests have shown promise in measuring particle characteristics. Anfindesen et al., Pat. No. 5,420,040 correlated the precipitation of asphaltenes in oil with changes in conductance or capacitance. However, this method requires transferring a sample of the liquid to be measured to a measuring cell and is not performed online. Furthermore, the process is staggered and cannot be performed substantially instantaneously as a delay is required to allow precipitation of the asphaltenes to occur. Behrman and Larson, MBAA Technical Quarterly, 24, 72-76 (1987) describe online tracking of particles larger than 0.8 microns in brewery streams using an ultrasonic monitoring device. They use a piezoelectric transducer to generate an acoustic signal and to detect the acoustic energy that is derived from the dispersion of particles in liquid streams. The device allowed the measurement of the concentration of the particles in line and in real time, but not the measurement of the sizes of particles nor of the distribution of the size of particles.
More recently, Lin, et al., "Neutron Scattering Characterization of Asphaltene Particles," presented at the ACS National Meeting, San Francisco, CA, April 1997, reported the use of small-angle neutron diffusion
ES 2 272 011 T3 (SANS) to determine the size and concentration of asphaltene particles in a solution diluted in 1-methylnaphthalene-D10. The study concentrated on small “basic” asphaltene particles and reported that the larger particles, which may be important for macroscopic properties, could not be measured by today's small angle diffusion equipment and would be very difficult. If not impossible, measure them with light diffusion methods.
De Boer, et al., SPE Production & Facilities, pp. 5-61, February (1995), reported research on asphalt precipitation in oils and described the use of back-diffused energy from an acoustic probe to detect asphaltene particles. A multichannel analyzer was used to classify the signals into two amplitude classes corresponding to large and small particle sizes.
The acoustic detection procedure was used to monitor the relative number of large and small particles during the titration of petroleum heptane to induce asphalt precipitation. Since the method required the addition of significant amounts of n-heptane to the oil, it would not be practical to apply the test to an in-process or real-time stream. Furthermore, the titration procedure required a significant time to finish each sample and did not lend itself to a quick and easy measurement of the agglomeration state of asphaltenes in a laboratory. The publication did not disclose a method for interpreting diffused acoustic energy measurements without the addition of n-heptane to initiate precipitation and did not provide any reason to do so.
Later, a group from the same laboratory reported the use of the same ultrasonic particle analyzer in the laboratory to study the usefulness of asphaltene inhibitors. (Bouts, et al., J. Petr. Tech, 782-787, September, 1995). The method included a test cell attached to a sonic probe that acts, as previously described, to measure the diffused energy of the particles in the liquid. A multichannel analyzer counted the particles and classified the detected diffused energy into thirteen amplitude classes. The two channels that measure the smallest particles and the remaining 11 channels that measure the largest particles were grouped respectively to track “small” and “large” particles versus time when the sample was titrated with n-heptane to destabilize the particles. asphaltenes. The purpose of the method was to test various inhibitors by monitoring the formation of the asphaltene agglomerates as a function of the added heptane and the content of the inhibitor. The study did not reveal how to interpret or use the particle size distribution data for more than two particle size ranges or without the addition of heptane. Furthermore, the article did not reveal how the state of agglomeration of asphaltene particles in a liquid hydrocarbon could be determined in real time, without dilution or without removing a sample of the liquid from the stream or tank in which it is contained.
From US 5,121,629 a method is known for determining the size distribution and concentration of particles in suspensions using ultrasonic excitation at selected discrete frequencies over a selected frequency range, wherein the attenuation of the ultrasonic waves passing through the suspension is measured for each of the selected discrete frequencies to obtain from this a spectrum of the measured attenuation for the suspension over the selected frequency range. Then, a set of attenuation spectra for the ultrasonic waves passing through the suspension over the selected frequency range is calculated using a set of original particle size distribution and concentration values. A comparison is then made between the measured attenuation spectrum and the calculated attenuation spectra to derive an approximate combination between at least one of the calculated spectra and the measured spectrum.
Also known is the characterization of grain size using the backscattered signals of "The quantitative evaluation of grain size using ultrasonic backscattered echoes", J. Saniie, NM Bilgutay, The Journal of the Acoustical Society of America, US, American Institute of Physics, New York, Vol. 80, No. 6, December 01, 1986, pages 1816 to 1824. In this document a heuristic model is investigated that relates the statistical characteristics of the measured signal to the mean ultrasonic small wave and the attenuation coefficient. Losses in the backscattered signal are examined using a time average, a correlation, and a probability distribution functions of the segmented data. In addition, this method uses homomorphic processing to estimate the average ultrasonic small wave propagating through the sample and the frequency-dependent attenuation.
US 4,509,360 discloses a method for the measurement of particle agglomeration or dispersion in fluid mixtures, where a repeating broadband ultrasonic wave is produced by a transducer and sent to the lenses, which also serves to isolate the transducer mix. Since the intensity of the wave is large in the interrogation zone, small changes in the impedance of the fluid in this zone, caused by the passage of the agglomerates, will cause large fluctuations in the intensity of the back-diffused wave, which is controlled by the transducer between pulses and displayed by appropriate electronic elements. In this way, large agglomerates can be determined in the fluid, for example, greater than 10 microns in diameter.
In general, other systems for the ultrasonic measurement of particles in liquids are described in US 4,412,451 and US 4,706,509.
Thus, and despite the progress of promising techniques in related areas, an appropriate method is not available to measure the agglomeration state of asphaltenes in oil, such as crude oil or any other optically opaque liquid hydrocarbon, quickly. and without dilution of the sample in a laboratory, or in real time and without diluting or removing a sample from the process stream. The lack of such a method has also limited the ability to control agglomeration of asphaltenes in such oils.
ES 2 272 011 T3
Brief description of the drawings
Figure 1 is a block diagram of the components of a system that can be used to practice one embodiment of the present invention;
Figure 2 depicts a diagram of a focused acoustic probe mounted on a distribution pipe in which the direction of the liquid fluid is indicated by the arrow and the focal region of the acoustic signal is indicated by the intersection of the dashed lines.
Figure 3 shows a diagram of a system that can be used in applications in the field of the present invention where the acoustic probe is shown mounted in a retractable system;
Figure 4 is a block diagram of a system that can be used in the present invention to acquire and transform the broadcast acoustic signal into a magnitude vs. frequency format.
Figure 5 is a magnitude vs. frequency graph of the back-diffused acoustic energy detected in undiluted and untreated crude oil within a frequency range of approximately 0.01 MHz to 20 MHz;
Figure 6 is a magnitude vs. frequency plot of the back-diffused acoustic energy detected within a frequency range of approximately 0.01 MHz to approximately 20 MHz in undiluted crude oil that has been treated to suppress the formation of asphaltene particles. ;
Figure 7 is a magnitude vs. frequency plot of the data in Figure 5 and Figure 6 illustrating a method for comparing the magnitude vs. frequency data for a liquid oil or hydrocarbon against a standard.
Figure 8 is a block diagram of a system that can be used to implement an embodiment of the present invention in which the measurement of the agglomeration state of asphaltenes in a liquid hydrocarbon initiates an action to control the agglomeration;
Figure 9 is a side view of a measuring cell having an adapted transducer, in order to be used on a small scale or in the laboratory to practice an embodiment of the present invention;
Figure 10 is a plan view of a metering cell having two transducers adapted for use on a small scale or in the laboratory to practice one embodiment of the present invention; Y
Figure 11 is a diagram of a system that can be used in sustained applications of the present invention where two acoustic probes are shown in a cross-sectional view of a pipe in which each acoustic probe is mounted through the wall. of the tubing in a retractable system.
The characters of the corresponding reference indicate fully corresponding parts in the various views of the drawings.
Summary of the invention
The present invention, therefore, is directed to an improved method for measuring the agglomeration state of asphaltenes in an asphaltene-containing oil, which comprises applying an acoustic energy signal to the oil, thereby diffusing at least a part of the energy, the detection of acoustic energy diffused over a selected frequency range, the resolution of the magnitude of the diffused acoustic energy detected at selected frequencies within the selected frequency range and the determination of the agglomeration state of the asphaltenes by comparing the magnitude vs frequency data with a standard. This method can be used to measure the agglomeration state of oil in a process flow stream or in a small sample that has been removed from the oil body.
An additional embodiment of the present invention is a method for determining the agglomeration state of asphaltenes in an oil containing asphaltenes, which comprises the removal of a sample of the oil and without diluting it, applying an acoustic energy signal to it, by which at least a part of the energy is diffused, detecting the magnitude of the acoustic energy diffused over a selected frequency range; the resolution of the magnitude of the diffused acoustic energy detected at selected increments within the selected frequency range, deriving from said resolution a distribution of the relative size of the asphaltene particles that diffuse the acoustic energy within the selected frequency range, and the determination of the agglomeration state of the asphaltene particles. Optionally, the sample can be returned to the oil mass. A further embodiment provides a method of controlling the agglomeration of asphaltenes in oil comprising applying an acoustic energy signal to the oil, thus diffusing at least a part of the energy, detecting the energy diffused over a range of frequencies selected, the resolution of the magnitude of the diffused energy detected at selected increments within the selected frequency range, the comparison of the detected diffused resolved energy with a standard, acting in such a way as to control the number of particles having a particle size corresponding to that of the selected incremental frequencies.
ES 2 272 011 T3
Among the various advantages of this invention can be noted the provision of a method for determining the state of agglomeration of asphaltenes in a petroleum, such as a crude oil or a process stream of a liquid hydrocarbon, in real time, the provision of such a method that can be performed either online, without removing a sample from the process stream or with a sample of oil that has been removed from the oil body; the provision of a method that does not require dilution of the oil or the addition of another material thereto, and the provision of such a method that facilitates the control of agglomeration of asphaltenes in the oils.
Detailed description of the preferred modalities
In accordance with the present invention, it has been discovered that the concentration and distribution of the relative particle sizes of asphaltene in oil can be measured in real time by applying an acoustic energy signal to the oil, thereby causing at least some part of the signal is distributed when it encounters the asphaltene particles within the oil and detects the acoustic energy diffused over a selected frequency range. The magnitude of the detected diffused acoustic energy can be resolved at selected frequencies within the selected frequency range. If desired, a relative size distribution of the asphaltene particles that diffuse acoustic energy within the selected frequency range can be calculated from the magnitude vs. frequency data, by correlating the measured data with a known standard or model. Whether or not the magnitude vs frequency data correlate with the particle size distribution, the state of agglomeration of the asphaltene particles in oil can be determined by comparing the magnitude vs frequency data, or the particle size distribution with a standard for the differences between the two to indicate the state of agglomeration of the asphaltene particles in the oil. As used herein, the term "agglomeration state" means the relative particle size distribution and is meant to include data that, under correlation to a known standard or model, will produce such a relative particle size distribution.
Actions to control agglomeration of asphaltene in oil can then be based on such a measure. Furthermore, in one embodiment of the invention, the use of, for example, an oscilloscope and a computer to rapidly resolve the detected diffused energy in magnitude at each of the selected frequencies from a large number and to derive a relative size distribution of particle allows measurement to be performed in real time. Also, because the determination of the agglomeration state of the asphaltene can be carried out without titration, or other modification or dilution of the liquid being tested, the method can be used online and without dilution, or else they will be contaminated. , the process flow stream or any samples that may be taken.
In the present application, the term "oil" means crude oil and any other liquid hydrocarbon. While the method of the present invention can be used on any petroleum, it is most advantageously used on an asphaltene-containing petroleum, but the most advantageous way of all is when it is used on oils that are optically opaque.
A system that can be used to practice the present invention is shown in the block diagram of Figure 1. In general, a pulse generator, or push button 30, generates an electrical signal that is transmitted to an acoustic probe 10 that transduces the electrical signal into an acoustic signal that is transmitted to the oil to be analyzed. The same probe, or optionally, a separate sensor 20, detects an "echo" of the acoustic signal that is produced by the diffusion of the signal when it encounters asphaltene particles in the oil. An amplifier 40 amplifies the detected diffused signal and transmits the amplified signal to an oscilloscope 50 which converts the analog signal to digital, selects that part of the detected diffused signal that results from the diffusion in the focal region of the probe (whose selection step it is called “gate circuit activation”), and it transforms the amplitude vs. time signal into a magnitude vs. frequency distribution. The distribution is transmitted to a computer 60 which compares the distribution to a standard and determines the agglomeration state of the asphaltenes in the oil.
As would be readily recognized by a person of ordinary skill in the ultrasonic measurement craft, the system described above could easily be modified while still performing the same functions. For example, the electrical signal to be transmitted to probe 10 could be generated by oscilloscope 50, or a combined pulser / amplifier, as well as by pulser 30. Alternatively, the oscilloscope 50 could provide an amplification of the detected signal and replace the separate amplifier 40. Likewise, if desired, the computer 60 could fulfill the calculation functions attributed above to the oscilloscope 50.
The various parts of a system for practicing the present invention and their operation are described as follows.
The acoustic probe 10 may be a targeting ultrasonic transducer that applies an acoustic energy signal to the oil. The probe generally includes a piezoelectric crystal capable of transforming electrical signals into physical pulses. If the crystal is in contact with a fluid, such physical pulses are transferred to the fluid and initiate waves that have a frequency that is controlled by the frequency of the electronic signal. Preferably, probe 10 also contains a lens to focus the signal as illustrated by the broken lines in Figure 2. The focal length of probe 10 is the distance from the end of the probe to the point where the wave patterns converge. . The point where wave patterns converge is sometimes referred to as the "focal region." While the focal length is not critical, it is preferable for the focal length that it is less than the distance from the lens of probe 10 to any opposite conduit or tank wall, or opposite wall of a metering cell; that is, the focal region should be
ES 2 272 011 T3 within the fluid of interest. A probe 10 having a focal length of approximately 100 mm is suitable for the present invention as long as no wall, pipe or other structure of the process equipment intervenes between the probe 10 and the focal region.
As used herein, the terms "probe", "sensor" and "transducer" mean the same thing and are sometimes used interchangeably. Often the word "probe" is used to describe a transducer when it is primarily used to transmit a signal and "sensor" is used when the transducer is primarily used to receive or detect a signal.
The acoustic probe 10 should be capable of sending an acoustic signal having a duration, amplitude, and frequency range appropriate to the invention. Such a signal can be a pulse or a "tone burst".
If the signal is a pulse, it can be transmitted to probe 10 as a short-lived, high-voltage transient voltage spike, typically repeated many times per second. For example, a 5 MHz probe that can transmit a 300 volt signal in 10 nanoseconds (ns) is appropriate for some applications of this invention. However, a 10 MHz probe is preferred, while a 100 MHz probe is more preferred and a 200 MHz probe is the most preferred of all.
If the signal is a burst of tones, it can be directed to the oil instead of the transient voltage spike, or pulse, just described. The tone burst sweeps the frequency spectrum selected for use and each frequency is detected and analyzed separately. The tone burst will preferably have a duration of between 4 and 8 cycles. The actual time of the duration will depend on the period (T) of the tone. If there are (n) cycles in the tone, then the duration will be nT.
The typical operation of an acoustic probe and ultrasonic systems similar to those suitable for use in the present invention is described, for example, by Urick, RJ, J. Appl. Phys, 18, 983-987 (1947); McClements, DJ, et al., J. Phys. D: Appl. Phys, 22, 38-47 (1989); Holmes, AK, et al., J. Coll. Int. Sci, 156, 261-268 (1993); McClements, DJ, Adv. Coll. Int. Sci, 37, 33-72 (1991); McClements, DJ, J. Acoust. Soc. Am, 91, 849-853 (1992); Pinfield, V. J., et al., J. Coll. Int. Sci, 166, 363-374 (1994) and McClements, DJ, The use of ultrasonics for the characterization of oils and emulsions, Ph.D. thesis, Department of Food Sciences, University of Leeds, UK (1988) ; each of which is incorporated herein by reference.
The probe should be capable of withstanding a temperature up to 200 ° C, preferably up to 300 ° C, and most preferably up to 500 ° C. The probe should also be capable of withstanding a pressure of up to about 10 Pa and preferably up to about 250 Pa and more preferably up to about 500 Pa. Furthermore, the probe should preferably be capable of resisting chemical corrosion and physical erosion caused by the oils in the ones that will be employed.
Appropriate probes can be obtained commercially or manufactured. One type of commercially available acoustic probe for use in the present system is a 10 MHz barium titinate ceramic probe with a Balteau-Sonatest UFD-1 ultrasonic meter.
In one embodiment, the acoustic probe 10 can also be used as a sensor to detect the acoustic energy diffused by the particles in the oil. Only one transducer is required for this arrangement and the same transducer serves as the signal input probe and sensor. Alternatively, an input probe 10 can be used with one or more separate sensors 20. Referring to Figures 1, 10 and 11, if a separate sensor 20 is used, it can be positioned anywhere in the fluid relative to probe 10, but close enough to receive the diffused energy from the focal region. However, probe 10 and sensor 20 cannot touch each other. In Figure 10, the separate probe 10 and sensor 20 are depicted as mounted in a sample meter cell, as would be used on a small scale or in the laboratory. In Figure 11, separate probe 10 and sensor 20 are depicted as they would mount on retractable probes which might be appropriate for in-line mounting in a pipeline conducting a process flow stream. Although a separate sensor 20, if used, can be positioned almost anywhere in the fluid relative to the probe 10, it is preferred that the sensor be positioned close to the probe, but mounted in such a way that the direction of the probe signal intersects the direction of the sensor signal at or near the focal region of each other at an angle less than about 90 °. When the sensor is said to be located “close” to the probe, this means that the sensor is positioned so that it is capable of detecting the back-scattered energy produced by the probe's input signal. Preferably the sensor is positioned within about two meters of the probe, more preferably within about one meter and even more preferably within about 0.25 meters of the probe.
As used herein, the term "signal direction" is expressed to mean the perpendicular and far direction of the face of a transducer, the direction of which extends along a line passing from the center of the face. active transducer across the focal region for that transducer, as shown, for example, in Figure 2. The active face of a transducer is that part through which acoustic signals are exchanged with the fluid with which the transducer is in contact. An advantage of using a separate probe and sensor is that the probe and sensor can be located so that the input signal generated by the probe does not interfere with the backscatter energy detected by the sensor. Since the backscattered energy is often significantly lower in strength than the input signal, the removal of the interference from the input signal
ES 2 272 011 T3 input allows a clearer and more sensitive reception of the energy back-diffused by the sensor. Furthermore, the lack of interference caused by the input signal allows handling of the signal and simplifies the interpretation process, as will be discussed later. It is preferred that the probe and sensor are located so that the direction of the probe signal intersects the direction of the sensor signal at an angle less than about 90 °, more preferably at an angle less than about 60 °, but the Most preferred option is at an angle less than about 45 °. By way of example, and assuming that the probes and sensors shown in the figures are in the same plane, the direction of the signal from probe 10 shown in figure 1 apparently intersects the direction of the signal from sensor 20 at an angle of 180<sup>°</sup> while the directions of the sensor signal and the probe of figure 10 shown in figure 1, apparently intersect at an angle of 60<sup>°</sup> approximately and the directions of the sensor signal and the probe in Figure 11 intersect at an angle of 28<sup>°</sup> about. It should be noted that the actual intersection of the probe and sensor signal directions is not required for the invention to be operable. Rather, only such description is used to indicate the preferred location of the probe and sensor.
The sensor, if it corresponds to the probe 10, or to a separate sensor 20, converts the acoustic waves from the diffused acoustic energy that collides with the piezoelectric crystal to an electrical signal. The operation of an acoustic energy sensor is generally described by the references given earlier in the section describing the probe 10.
It is preferable that the sensor of the subject system has the appropriate sensitivity to detect backscattered energy at frequencies up to 20 MHz, but a probe that can detect backscattered energy up to 100 MHz is more preferable but a probe that can measure is most preferable. back-diffused energy with frequencies up to 200 MHz.
The acoustic probe 10 may be mounted in a retractable mount, as shown in Figure 3 and Figure 11, for controlled insertion of the probe into a pipeline or reservoir. The retractable mounting allows the probe 10 to be easily removed from contact with the liquid for maintenance or replacement purposes without disassembling the reservoir or tubing. The retractable mount can be manually activated or can be powered by a motor. The design of the mounting that is used for the probe 10 is not critical and any technician of ordinary skill in the art might be able to design an appropriate mounting.
A push button 30 provides the necessary input signal to drive the probe 10 transducer. As mentioned above, the oscilloscope 50 can also be used to generate the input signal.
An amplifier 40 amplifies the detected broadcast signal before it is transmitted to oscilloscope 50. Push button 30 and amplifier 40 may be separate components or they may be combined into a single component. For example, a UTEX UTP320, from UTEX Scientific Instruments, Inc, provides the functions of pushbutton 30 and amplifier 40 in a combined component.
The oscilloscope 50 of the present system should be able to activate the gate circuit of the diffused acoustic signal, carrying out an analog to digital conversion and, preferably, transforming the signal from an amplitude vs. time format to a magnitude vs. frequency format. The activation function of the gate circuit limits the signal to the detected energy diffused by the particles within the focal region (region "B" in Figure 4). Thus, it eliminates that part of the signal due to the input pulse (region "A" in figure 4), any reflection due to an opposite pipe wall, and all other portions of the signal except for diffusion due to the particles in the focal region. When a separate probe 10 and sensor 20 are used in a preferred configuration as described above, sensor 20 does not detect any part of the signal due to the input pulse. Thus, gate circuit activation is not required for a system that has a separate probe and sensor that are located in a preferred configuration.
Oscilloscopes that are suitable to be used in the present system are for example a LeCroy Model 9450 and a Lecroy Model 9320. Such oscilloscopes should be complemented with appropriate software for waveform processing, such as for example Waveform. Processing Packages One and Two, available from LeCroy. The data from the oscilloscope is transferred to a computer 60 using, for example, a National Instruments IEEE Plug and Play adapter.
A computer 60 is used in the present system to receive the signal from the oscilloscope 50 and to store the waveforms for future reference and also to compare the waveforms against reference scanners and other standards, to run the size models of particulate matter and analysis, to determine the agglomeration state of the asphaltenes in the oil and to initialize any desired alarm or control action.
As long as the type and computational speed of the computer are not critical, it is preferred that a personal computer with a Pentium 7 processor, or its equivalent, and with spreadsheet software such as Microsoft Excel 7, is the used in the present system.
The various components of a system suitable for practicing the present invention should be interconnected as indicated in Figure 1 and to other necessary electrical resources or components to allow the proper and intended operation of each component. In general, the probe 10 should be connected so as to receive an input electrical signal from the pushbutton 30 and to transmit a detected diffused acoustic signal to the amplifier.
ES 2 272 011 T3
40. The amplifier 40 should be connected to transmit an amplified diffused acoustic signal to the oscilloscope 50. The oscilloscope 50 is connected to the computer 60 so that after performing the necessary triggers of the gate circuit and transformation stages, it can transmit data to the computer 60 for further calculations. which lead to the determination of the agglomeration state of the asphaltenes and the activation of any desired alarm or control functions.
The present method for measuring the agglomeration state of asphaltenes in asphaltene-containing oil is carried out by applying an acoustic or ultrasonic energy signal to the oil. The present method is capable of determining the agglomeration state of asphaltenes in almost any oil containing asphaltenes, but is especially useful for crude oil, other optically opaque streams, or streams and samples where other detection methods are online or in-line. real time cannot be operational due to high pressures or high temperatures.
In one embodiment, the method of the present invention can be applied to an oil in a process flow stream under real-time conditions. In this application, the acoustic signal is preferably applied to an oil for which the state of agglomeration is to be determined prior to any dilution thereof that may be involved in the processing to which the oil is subjected (e.g. refining), and without dilution or adulteration of the oil during the application of the signal. The sounder 10 is most preferably installed in the reactor, vessel, exchanger, pipeline, tank, or other container or conduit in which the oil is stored, transferred, or processed so that the signal can be applied to the oil in the flow stream. without removing it from such process flow stream, thus avoiding disruption or interference with the storage, transfer or process to which the oil is subjected.
The term "process flow stream" as used herein, means any stream or mass of oil that does not correspond to a small sample and is intended to include oils in pipelines, reactors, heat exchangers, tanks, pumps, conduits. , pipes, or any other container or conduit in which oil is stored, handled, processed, transported, or transferred in a conventional manner, from or during processing or storage, but it does not mean including small oil samples that, for testing purposes, have been removed or separated from the oil mass from which the agglomeration state of the asphaltenes is to be measured or controlled.
When a test, probe, or instrument is said to be applied "in-line," this means that the test, probe, or instrument of interest is applied directly to the process flow stream, rather than to a sample from such stream.
The acoustic signal should be applied to the liquid as a pulse or a continuous series of pulses, or as a burst of tones. The frequency range of the acoustic signals of most interest in the present method is around 0.1 MHz to approximately 200 MHz.
Acoustic waves are reflected when they hit an interface between the liquid and a discontinuity, such as a particle. When the acoustic signal propagates through the liquid, it finds any particles that are in its path. When using a focused echo sounder, the acoustic signal converges on a focal region creating a particularly strong signal at that point. When the signal encounters a particle, a part of the acoustic energy is diffused. Different sized particles cause energy to be diffused at different frequencies. Additionally, the more particles that are present in the signal path, the greater the amount of acoustic energy that is diffused. Therefore, a particular particle size and number distribution in a liquid results in a diffused acoustic energy characteristic for both particle size and number. Since crude oils and other in-process oils are largely free of microscopic particles other than asphaltene agglomerates, the particle size distributions obtained from the acoustic diffusion technique correspond to the distribution of asphaltene particles.
The diffused acoustic energy is detected by a sensor or detector as described above. While the probe 10 can also act as a sensor for the back-scattered energy, separate sensors 20 can be positioned in reference to the signal probe, as previously described to detect subsequent diffusions, or the energy diffused at any other angle. For some embodiments, the detection of backscattered energy is preferred for adaptation to an online device, since, for example, a probe can act as both a signal probe and a sensor.
When asphaltenes agglomerate to form particles, the first particles can be relatively small, comprising perhaps only a few molecules of asphaltenes. However, if the conditions that favor agglomeration persist, the asphaltene particles will grow. It is important, therefore, that the diffused acoustic energy be detected in a range of frequencies that includes the characteristic frequencies for the energy diffused by the particular asphaltene particles in the oil. The inventors have discovered that this characteristic frequency range can vary with the type of oil and the type of process it is subjected to. If the energy diffused over the wrong frequency range is measured, any of the asphaltene agglomerates that form can be totally lost. Thus, a characteristic frequency range may have to be calibrated and optimized for each system installation. As long as one is aware of the need to determine an appropriate frequency range, this can easily be done by a person skilled in the art and not without due experimentation.
ES 2 272 011 T3
Detection of diffused acoustic energy over a frequency range from approximately 0.1 MHz to approximately 20 MHz is appropriate for determining the agglomeration state of asphaltenes in ordinary petroleum, but in order to ensure detection of a wider range of particle sizes, detection is most preferable over a frequency range of about 0.1 MHz to about 100 MHz but detection over a frequency range of about 0.1 MHz to about 200 MHz is the most preferred of all. However, once the characteristic of the frequency range has been determined for the energy diffused by the particular asphaltene particles in a particular oil, it may be useful to detect the energy diffused only over, or within this more limited range.
If a transient voltage spike, or pulse, or input signal is used; the echo, or broadcast signal, is detected as a plot of amplitude vs. time that results from each of such input pulses, as illustrated in the figure
Four. This graph of the amplitude of the diffused signal received from each pulse vs time shows the signal detected as a transient voltage peak at time = 0, indicative of the input pulse itself, and from there, the sensor detects the acoustic energy diffused by the material in the path of the acoustic wave. The distance along the "time" axis corresponds to the distance from the end of the probe because the time required for a wave to hit a particle and reflect it back into the probe is controlled by the speed of sound in the probe. oil and the distance of the particle from the end of the probe.
The amplitude of the detected energy is proportional to the concentration of the particles in the signal path. A particularly strong response is received from the focal region due to the convergence of the input signal at that point.
The signal received by the sensor is amplified using a narrow band amplifier and tuned until the fundamental frequency of the transducer fits. If a simple probe is used, the signal is driven to the gate circuit to focus on the diffusion of the focal region and can then be converted to a digital signal by an analog / digital converter. If separate probes are used to generate the input signal and to detect the backscattered energy, the gate circuit triggering step can be avoided when the probe and sensor are located in a preferred configuration, as previously described.
The converted, amplified signal is then resolved into a magnitude vs. frequency format so that the relative particle size distribution can be correlated and the agglomeration state of the asphaltenes can be determined. Methods for accomplishing this resolution are described by McClements, DJ, et al., Ultrasonics, 31, 433-437 (1993); McClements, DJ, et al., J. Coll. Int. Sci., 160, 293-297 (1993); Dickenson, E., et al., J. Coll. Int. Sci., 142, 103-110 (1991); and McClements, DJ, and MJW Povey, Ultrasonics, 30, 383-388 (1992); the references of which are incorporated herein by reference.
The amplified signal, activated with the gate circuit (if necessary) and converted, is transformed from an amplitude vs. time format into a magnitude (decibels, dB) vs. frequency (MHz) format, by Fourier transformation. The magnitude vs frequency data is then averaged, preferably above approximately 200 pulses, and exported either to the oscilloscope or to the computer screen to be presented as a magnitude vs frequency graph, as indicated in Figures 5 and 6, or to the computer for storage and subsequent computations.
Once the detected signal is resolved into magnitude vs. frequency data, a relative size distribution of asphaltene particles that diffuse acoustic energy within the selected frequency range can be derived if desired. This derivation can be made by correlating the frequency, at any specific frequency within the frequency range of interest, with a particular known particle size. This can be done by obtaining the frequency response data for standard mixtures containing particles of known sizes, or by predicting a frequency vs. particle size correlation model based on diffusion theory. Comparison against a known standard has been described by Povey, MJW, and MG Scanlon, J. Coll. Int. Sci., 93 (2), 565-566 (1983), which is hereby incorporated by reference. The correlation of particle size with frequency by comparison with a diffusion theory model has been described by Pinfield, VJ, et al., Ultrasonics, 33 (3), 243-251 (1995). This model can be improved with corrections for thermal distribution effects as described by Pinfield, VJ and MJW Povey, J. Phys. Chem. B, 101, 1110-1112 (1997), each of these references is incorporated by reference .
Alternatively, the relative particle size distribution can be obtained from amplitude and phase vs frequency data, as well as amplitude vs time data.
An advantage of the present invention over the preceding methods is that it provides a method for resolving a particle size distribution at almost any number of discrete particle sizes within the range of particles that are detected within the selected frequency range. This is done by selecting the number of discrete frequencies within the selected frequency range in which the relative particle size is correlated. It is preferred that the relative particle size is determined at at least three different frequencies within the selected frequency range. It is more preferred that the relative particle size is determined at at least 15 different frequencies within the selected frequency range and even more preferred, that the relative particle size is determined at least 30 different frequencies within the selected frequency range.
ES 2 272 011 T3
The next step is to compare the magnitude vs. frequency data, or the particle size distribution, with some standards and determine the agglomeration state of the asphaltenes.
The magnitude vs. frequency data represent a relative particle size distribution, rather than absolute particle sizes, and either relative or absolute particle size distributions can be used as a measure of the agglomeration state of the particles in oil. The distribution as measured in the oil is compared to a standard having a known agglomeration state and the differences between the measured distribution and the standard indicate the agglomeration state of the measured oil. For example, the baseline at a magnitude of 0 dB as shown in Figure 5 could serve as the standard by comparing it to the measured distribution of crude oil. The utility of such a simple standard is illustrated by the similarly flat distribution shown in Figure 6 of crude oil treated with a caking inhibitor and having no particulates. The transient voltage spike signal in Figure 5 between about 14 MHz and 20 MHz is attributed to asphaltene particles in crude oil.
The use of a standard of a crude oil treated with a caking inhibitor is shown in Figure 7, where the magnitude vs. frequency distribution of the standard is superimposed on the same data for a crude oil. As noted above, the differences of the two signals in the frequency range between approximately 14 MHz and approximately 20 MHz indicate the presence of agglomerates in the crude.
Since the operation of the acoustic and electronic stages of the present invention are performed very quickly and as neither stage requires waiting for a change in the liquid to occur (as in the methods disclosed by Bouts, de Boer and Anfindsen), or requires the titration or addition of any material to the liquid (as in Bouts and deBoer), the determination of the agglomeration state is carried out substantially instantaneously and can be advantageously applied in real time in the processing of vapors and the like. In the present case, "substantially instantaneous" means that the measurement can be carried out in less than about a second. It is understood, however, that the system applying the present method can take such measurements continuously and, if desired, can average the results of various measurements taken over any desired period of time.
The use of the present invention in a small scale device or in the laboratory is a further embodiment of the present invention. In an appropriate method for this application, a liquid sample can be removed or taken from the container where the oil is in which the agglomeration state of the asphaltenes is to be determined. The same stages of application of acoustic energy, detection of diffused energy, and resolution, derivation and determination of the agglomeration state of the asphaltenes is carried out on the undiluted oil as described above, except that the application and the Detection is done in a flow cell, or measurement cell, rather than in a process or tank. Examples of such measurement cells are shown, for example in Figure 9 and Figure 10. After such measurements are completed, the sample of the undiluted and unadulterated oil can be returned or disposed of as desired. An advantage of returning the undiluted and uncontaminated oil to the oil body is that no additional expense or effort is required to dispose of the hydrocarbon samples.
A further embodiment of the present invention is a method of controlling agglomeration of asphaltenes in petroleum. A system such as the one shown in Figure 8 can be used for such a control function. The method involves the steps of applying an acoustic energy signal to the oil and detecting the energy diffused on a selected frequency as described above. The sensed energy is then resolved in magnitude at selected increments within the selected frequency range. The magnitude of the detected diffused energy is related to the number of particles of a certain size and for control purposes, it is not necessary to derive the distribution of the relative particle sizes, but only to compare the magnitude of the signal detected in one or more more frequencies selected with a standard, in order to make the decision to act to control the number of particles that correspond to the particular frequency or frequencies.
As an application of the present invention is calibrated and tuned for a particular application, it may be desirable to limit the range of frequencies selected for detection of diffused acoustic energy in the frequency range diffused by the agglomerated asphaltene particles characteristic of petroleum. Preferably, the frequency range selected to detect diffused acoustic energy is from about 14 MHz to about 20 MHz.
The action to control the number of particles can take any number of forms. For example, the device can cause a change in process conditions such as flow rate, temperature, or pressure, or it can cause the addition of a caking inhibitor, surfactant, or other chemical additives. Alternatively, the control can be to divert a current, or to slow, speed up, or stop a process.
Figure 8 shows the use of the method to measure the state of agglomeration in a control loop. The control loop may include the computer 60 and a control actuator 70, with the feedback data provided by a system applying the method for measuring agglomeration status of the present invention.
Several particularly useful characteristics are provided by the method of measuring the state of agglomeration of asphaltenes in a petroleum. The measurement can be carried out in real time since there are no titrations or other additions to the oil and thus, no waiting caused by the changes induced by such additions. The App10
ES 2 272 011 T3 tion, detection and resolution of the acoustic signal is executed very quickly. Even if the detected diffused energy signal is averaged over 100 separate pulses, the relative particle size distribution can be derived and the agglomeration state of the asphaltenes determined in a time well below one second.
The acoustic probe can be installed directly in a tank or pipe containing the oil mass and the measurement can be done online. No sampling is necessary. As the test does not require dilution, if a sample is taken, it can be returned, if desired, to the oil mass without dilution or adulteration.
Additionally, due to the simple and rugged nature and materials of the sounder, the method can be used in streams and under conditions where other methods could fail due to temperature, pressure, or the corrosive quality of the oil.
Because of the characteristics described above, the method for controlling the agglomeration of asphaltenes in oil has the useful characteristic of constituting a real-time control technique. A signal from the measurement system substantially reflects the state of the oil in a process flow stream at a given time. Based on this information, actions can be taken to control the agglomeration of asphaltenes and the results of these actions can be controlled without an unacceptable time lag. A feedback control loop that has a constant time lag within normal practice is then possible. This allows the use of conventional industrial control equipment to effect process changes required by the controller (in this case the personal computer).
Industrial application
The measurement and control systems of the present invention can be used for any application in line, in a tank or in process that requires the measurement or control of the agglomeration state of asphaltenes in petroleum. The same measurement and control systems can also be used in a device designed for laboratory or small-scale operation.
One potentially useful application is during production at the wellhead, or in the hole, where changes in temperature and pressure often lead to precipitation of asphaltenes from crude oil. This results in the connection of pipes and equipment and requires periodic shutdowns and maintenance to remove the solids from the asphaltene. The installation of a measurement and control device based on the present invention would allow the addition of, for example, asphaltene precipitation inhibitors according to the required amount in order to minimize asphaltene agglomeration. This represents an improvement over adding such expensive chemicals on an ongoing basis because, in general, the less inhibitor used over time and preventing connections allows longer periods of operation.
The methods of the invention can also be applied to in-process streams, such as face-breaking streams, where hot and opaque liquids preclude most conventional particle sensors.
The following example describes a preferred embodiment of the invention. Other embodiments within the scope of the claims present herein will be apparent to the person skilled in the art from a study of the specification or practice of the invention as disclosed herein.
Example 1.
Measurement of the agglomeration state of asphaltenes in crude oil by an eco pulse technique
A system including a UTEX UTP 320 pulser / amplifier was employed to provide a pulsed electrical signal to a 10 MHz focusing ultrasonic probe. The probe tip was immersed in a sample of undiluted crude oil. The pulse signal used in this example had the following characteristics:
Voltage = 1 kV (1000 volts)
Duration = 3 nanoseconds Impedance = 70 Ohms Acoustic Power = 14285.7 Watts
Efficiency = 0.1
Acoustic power = 1428.57 watts
Transient voltage spike frequency = 1000 Hz
On / off ratio = 3 x 10-6
ES 2 272 011 T3
Average electrical power = 0.04286 watts Average acoustic power = 0.00429 watts
The probe also acted as a sensor to detect the back-diffused energy. The UTEX push button / amplifier amplified the detected signal and transmitted it to a LeCroy Model 9320 oscilloscope. The oscilloscope performed an analog-to-digital conversion of the signal and activated the signal gate circuit for back-diffusion by the particles in the focal region. The width of the gate circuit was approximately twice the duration of the backscattered signal (i.e., 2 //.S; corresponding to a focal region with a spatial measurement of approximately 3 mm in oil). The oscilloscope then performed a Fourier transform of the signal to convert it from an amplitude vs. time format to a magnitude vs. frequency format. The magnitude vs frequency data was averaged over 200 scanners before being exported to a personal computer for filing and additional computations in an Excel program spreadsheet. <sup>®</sup>. A graph of the resulting magnitude vs. frequency data is shown in Figure 5 over a frequency range of approximately 0.1 - 20 MHz. A solid line showing an average value for these data points is also included in the graph.
The same type of measurement as the one used above was carried out on a sample of the same oil, but to which a chemical inhibitor had been added to prevent agglomeration of the asphaltene. The magnitude vs. frequency graph for this inhibited sample is shown in Figure 6.
The computer compared the oil data (as shown in figure 5), with the standard (as shown in figure 6), superimposing one on the other as shown in figure 7. Alternatively, the graph in Figure 5 could simply be compared to an arbitrary baseline, such as the "magnitude 0" baseline shown in Figure 5, or to a model, or any other standard against which the state could be determined. of agglomeration of the substance not known.
In figure 7, the traces of asphaltene particles diffused primarily in the region of 14 MHz - 20 MHz can be contrasted with the lack of such diffusion in the inhibited sample of the same oil. This difference represents the degree of agglomeration of asphaltene in crude oil.
Contents8
10 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10
12 members in 6 offices
Priority claims5
| Document | Office | Kind | Date |
|---|---|---|---|
| 19970947821 | United States of America | – | |
| 94782197 | United States of America | A | |
| 94782197 | United States of America | A | |
| 98952180947821 | – | – | – |
| US19970947821 | – | – | – |
Members12
| Document | Office | Kind | |
|---|---|---|---|
| WO9919723A1 | World Intellectual Property Organization (WIPO) | A1 | |
| AU9793998A | Australia | A | |
| US5969237A | United States of America | A | |
| EP1021710A1 | European Patent Office (EPO) | A1 | |
| EP1021710A4 | European Patent Office (EPO) | A4 | |
| US6945096B1 | United States of America | B1 | |
| US2006156820A1 | United States of America | A1 | |
| EP1021710B1 | European Patent Office (EPO) | B1 | |
| DE69835826D1 | Germany | D1 | |
| ES2272011T3This record | Spain | T3 | |
| DE69835826T2 | Germany | T2 | |
| US7360403B2 | United States of America | B2 |
Numbers
- Publication
- 2272011
- Publication, DOCDB
- 2272011
- Publication, EPODOC
- ES2272011T
- Application
- 98952180
- Application, DOCDB
- 98952180
- Application, EPODOC
- ES19980952180T
Titles2
- Spanish
- MEDIDA Y CONTROL DE LA AGLOMERACION DE ASFALTENOS EN HIDROCARBUROS LIQUIDOS.
- English
- MEASUREMENT AND CONTROL OF ASPHALTEN AGLOMERATION IN LIQUID HYDROCARBONS.
Classification
- CPC, 10
- G01N15/02
- G01N29/032
- G01N29/341
- G01N29/348
- G01N29/42
- G01N33/2823
- G01N2015/0061
- G01N2015/0092
- G01N2291/02416
- G01N2291/0251
- IPC, 6
- G01N29 02
- G01N15 02
- G01N29 032
- G01N29 34
- G01N29 42
- G01N33 28