Apparatus and method for separating solids from a solids laden drilling fluid.

(54) Title: APPARATUS AND METHOD FOR SEPARATION OF SOLIDS FROM A SOLID DRILLED FLUID.

(54) Title: APPARATUS AND METHOD FOR SEPARATING SOLIDS FROM A SOLIDS LADEN DRILLING FLUID.

(57) Summary

The present invention relates to a vibrating screen to separate solids from the solids-laden drilling fluid, the vibrating screen comprises a basket (100) having a first screen assembly (122a, 122b) in an upper screen cover (112 ) and a second screen assembly (125a, 125b) in a lower screen cover (113), the basket (100) further comprises a flow tray (121) for feeding the solids-laden drilling fluid to a first conduit (107A-D) and a second conduit (108A-D), the first conduit (107A-D) to feed the solids-laden drilling fluid to the first screen assembly (122a, 122b) and the second conduit (108A-D) that feeds the solid-laden drilling fluid to the second screen assembly (126a, 125b) characterized in that the second conduit (108A-D) comprises a plurality of second openings in the conduit (103AD) to divide the supply of the solid-laden drilling fluid and at least one discharge opening (110B, 110D) to distribute the fluid drilling rig loaded with solids on the second screen assembly (122a, 122b; 125a, 125b).

(57) Abstract

A shale shaker for separating solids from solids laden drilling fluid, said shale shaker comprising a basket (100) having a first screen assembly (122a, 122b) in an upper screen deck (112) and a second screen assembly (125a, 125b) in a lower screen deck (113), the basket (100) further comprising a flow tray (121) for feeding solids laden drilling fluid to a first duct (107A-D) and a second duct (108A-D), the first duct (107A-D) for feeding solids laden drilling fluid to the first screen assembly (122a, 122b) and the second duct (108A-D) feeding solids laden drilling fluid to the second screen assembly (125a, 125b) characterized in that the second duct (108A-D) comprises a plurality of second duct openings (103A-D) for dividing the feed of solids laden drilling fluid and at least one discharge opening (110B, 110D) for dispersing said solids laden drilling fluid on to the second screen assembly (122a, 122b; 125a, 125b).

PATENT TITLE NO. 338439

I KNOW

BíKBOMB

Institute

Mexican Property

Industrial

<img file="MX338439B_D0001.tif" />

Owner (s): NATIONAL OILWELL VARCO, LP

Address: 7909 Parkwood Circle Drive, Houston, Texas, 77036, USA

Name: APPARATUS AND METHOD FOR SEPARATION OF SOLIDS FROM A DRILLING FLUID LOADED WITH SOLIDS.

Classification:

lnt.CI.8: B07B1 / 46

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«Íí

EORQfe ALEXAN0ER feURNETT; THOMAS REQUEST

LARSON

International filing date:

April 2011

PRIORITY

Country:

US i

^ Validity: Veterans i

Come &lt;amienfl&gt; Date:

Date:

April 2010

12 / 771,201 .a reference patent n · grants foundation in loó

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action V, 6th fraction lll, and 59 of the Industrial Property Law.

In accordance with art Tontada from the fecj Jerechos.

Duien subscribes to the Preser 'Industrial Property (Dial ilo 23 of pre day:

Title the Official &lt;8/01/2006, s Law of the Industrial Property the present paternal has a twenty-year history inadón of the intafflscional request and guara iimH * to the payment of the tnnfa to maintain '* Ύ * lace based on what dispuesttfffcr artfeutos 6 ° fractions lll and 7 ° bis 2 of the Federation (DOF) 06/27/1991, amended on 08/02/1994, 10/25/1996, 12/26/1997

---------------—, ------—--- irrigable, before the

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iw, cotwtcutu, crrorrcy, ι,,,, ιο ^. „ιι v subsection a), 4th and 12th sections I and lll of the Regulations of the Mexican Institute of Industrial Property (DOF 14/12/1999, amended on 07/01/2002, 07/15/2004, 07/28/2004 and 09/07/2007); Articles 1, 3, 4, 5, section V, Section a), 16 sections I and III 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, 08/04/2004 and 09/13/2007); 1, 3 and 5 subsection a) of the Agreement that delegates powers to the Deputy Directors General, Coordinator, Divisional Directors, Heads of Regional Offices, Divisional Deputy Directors, Departmental Coordinators and other subordinates of the Mexican Property Institute DOF 15 / 12/1999, amended on 02/04/2000, 07/29/2004, 08/04/2004 and 09/13/2007).

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Issue Date: April 18, 2016

THE DIVISIONAL DIRECTOR OF PATENTS

NAHANNY CANAL REYES

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Sand! No. 550. Floor 1

Co!. Pueblo Santa María Tepepan,

XachirrilbO, CP 15020,

Mexico City

Tei. (55) 53 34 07 00 www.impiqob.mx

ΜΧ / 201ΘΖ30176

i. · i

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APPARATUS AND METHOD FOR SEPARATION OF SOLIDS OF'WTJMJfó &amp; Ü'g)

INDUSTRIAL

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SOLID DRILLED DRILLING

Description of the Invention

The invention relates to a method and apparatus for separating solids from a solids-laden drilling fluid, and particularly, but not exclusively, to a method and apparatus for separating solids from a solids-laden drilling mud. The invention also relates to a vibrating screen and screen assemblies therefor.

In drilling a borehole in the construction of an oil or gas well, an auger is placed over the end of the chain of drill pipes, which is rotated to drill the borehole through a training. A drilling fluid known as drilling mud is pumped through the drill pipe chain to the bit to lubricate the bit. Drilling mud is also used to bring drill materials and other solids from the cut to the surface through an angle formed between the drill pipe chain and the drill hole. The density of the drilling mud is closely controlled to prevent the drill hole from collapsing and to ensure that drilling is carried out

REP.236338

IMPI

MEXICAN INSTITUTE Z OE IA PROPERTY Λ

INDUSTRIAL '**.

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optimally. The density of the drilling mud made it ugly. auger penetration speed. By adjusting the density of the drilling mud, the penetration rate possibly changes to the detriment of the drill hole collapse. Drilling mud can also carry lost circulation materials to seal the porous sections of the borehole. The acidity of the drilling mud can also be adjusted according to the type of formation strata through which the drilling is made. Drilling mud contains inter alia expensive synthetic oil-based lubricants and therefore it is normal to recover and reuse the used drilling mud, but this requires inter alia that the solids be removed from the drilling mud. This is accomplished by processing the drilling mud. The first part of the process is to separate the solids from the solids-laden drilling mud. This is accomplished at least partially with a vibratory separator, such as the vibrating screens described in US 5,265,730, WO 96/33792 and WO 98/16328. Additional processing equipment such as centrifugal machines and hydrocyclones can be used to further clean the sludge from solids. Solids are covered in contaminated materials and waste. It is not common to have 30 to

100 m³ of circulating drilling fluid in a borehole.

<img file="MX338439B_D0010.tif" />

The resulting solids, known here ..... as the perforation cut materials are processed to remove substantially all of the residues and contaminating materials from the solids. The solids can then be disposed of at an open-dump site or by dumping into the sea into the environment from which the solids come. Alternatively, solids can be used as a material in the construction industry or can have other industrial uses.

Vibrating screens generally comprise an open bottom basket that has an open discharge end and a solid walled feed end. A number of rectangular sieves are placed on the open bottom of the basket. Sieves can be substantially flat or can have a light crown. The basket is placed on springs above a receiver to receive the recovered drilling mud. A tub or channel is provided below the open discharge end of the basket. A motor is attached to the basket, which has a drive rotor provided with a weight of the centering mass. In use, the motor rotates the rotor and the weight of the mass off-center, causing the basket and the sieves attached to it to shake. The sludge loaded with solids is introduced into the feeding end of the basket on the sieves. The stirring motion induces

<img file="MX338439B_D0011.tif" />

IMPI

INSTITUTO MEXICANO OE LA PROPERTY INDUSTRIAL the separation of the drilling mud from the τόΐ-Ηηπ, no drilling passes through the sieves and the solids above the sieves. The stirring motion also induces the solids to move along the sieves towards the open discharge end. The recovered drilling mud is received at the receiver for further processing of the basket in the channel or tank.

Rectangular screens can be placed at an angle to the horizontal, such as about seven degrees inclined from the feed end to the discharge end of the vibrating screen. The angle can be adjustable. Sieves are generally attached to the basket and the basket is adjustable to adjust the angle of the sieves relative to the horizontal. The flow of the solids-laden drilling fluid can puddle on the inclined screens. The action of the vibrating mechanism induces the solids to climb on the inclined sieves to the discharge end of the screen and towards the channel or tank.

Generally, a vibrating mechanism that induces circular vibration will tend to push solids from the screen into the air in random directions. A vibratory mechanism that induces elliptical motion will induce solids to move in one direction of the longest chord in the ellipse. A vibrating screen that

INSTITUTO MEXICANO DE LA} 'ROI'IEF, Ar&gt; INDUSTRIAL has a vibratory mechanism that induces a — the very thin ipse is already known as a linear vibrating screen and induces rapid movement of solids along the sieve, although the sieve it tends to undergo rapid degradation due to the sudden deceleration of the solids when they are in the sieve.

Sieves are generally of one of two types: hook-pull, · and pre-tensioned.

The hook-and-pull type of the screen comprises several rectangular layers of the mesh in a sandwich, usually comprising one or two layers of a fine grade mesh and a support mesh having larger mesh holes and a gauge wire. heavier. The mesh layers are attached at each side edge by a strip that is in the shape of an elongated hook. In use, the elongated hook is hooked onto a tensioning device placed along each side of a vibrating screen. The vibrating screen further comprises a crowned set of support elements, which extend along the length of the screen basket, on which the mesh layers are tensioned. An example of this type of mesh is described in GB-A-1,526,663. The support mesh can

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be provided with, or replaced by, a panel that_ has openings in it.

The pre-tensioned type of the mesh comprises several rectangular layers of the mesh, usually comprising one or two layers of fine grade mesh and a support mesh having larger mesh holes and heavier gauge wire. The layers of the mesh are pre-tensioned on a rigid support that comprises an iron frame with rectangular angles and adhered to it. The mesh is then inserted into the C-channel rails placed in a vibrating screen basket. An example of this type of mesh is described in GB-A-1,578,948 and an example of a vibrating screen suitable for receiving pre-tensioned type sieves is described in GB-A2,176,424.

A problem associated with vibrating screens is that the sieves used here tend to clog, especially when the solids are rubbery, such as clay, or close to the mesh size of the sieve. This last type of plugging is known as a close-particle plugging. A number of solutions have been proposed to solve this problem, as described in GB-A-1,526,663 in which an assembly of sieves using two layers of a sieved material in a sandwich and allowing

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MEXICAN INSTITUTE OF LA ÍTOPIEDA »INDUSTRIAL

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the layers of the screened material move independently to dislodge any close-sized particles lodged in one of the screens.

It is advantageous to use fine mesh filters to filter very small particles, for example of a size in the range of 50-200 μ or greater, without the filter device being clogged with the small particles. However, it is the fine mesh filters in particular that are prone to such undesirable plugging.

It is also advantageous to have a reliable separator to inhibit downtime for maintenance and repair.

It is preferable in certain circumstances to retain the particles, for example of a particle size in the range of 50-60 µ or larger, by means of a filter.

In drilling an oil or gas well, there may be fractures in the wall of the borehole. Such fractures can spread, which could cause structural problems in the borehole wall and / or allow drilling fluids to leak through them into the formation. Also, if substantial amounts of the drilling fluids are lost, the pressure in the drilling fluid in the drill hole can be reduced, which could cause the well to collapse.

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INSTITUTO MFXICAUO, * - · «· ΓΕ THE PROPERTY C '.&gt;

INuUSTkl, \ L probing. Consequently, reinforcing materials from the drill hole can be added to the circulated drilling fluid. The borehole reinforcement materials comprise sized particles. When the drilling fluid is circulated around the borehole wall with fractures therein, the sized particles wedge themselves into the fractures, reducing the likelihood of fractures spreading. It is beneficial to recover these sized particles and reuse them in the circulated drilling mud. The vibrating screens have thus been modified to dimension the solids in the solid laden drilling fluid. Such a vibrating screen is described in USSN 12 / 490,492. A size range of solids can be extracted using such a vibrating screen and recycled as a drill hole reinforcing material in the fresh drilling fluid. It is desirable to retain some small particles such as barites that are frequently found in drilling muds, and therefore fine screens are preferably not too fine to screen bars from drilling mud.

In accordance with the present invention, a vibrating screen is provided to separate the solids from the solid laden drilling fluid, the vibrating screen comprises a basket having a first assembly of

MSXfCANr INSTITUTE. of the property

INDUSTRIAL sieves in a sieve rack superior 7¹ uu · -second__ screen assembly in a lower screen cover, the basket further comprises a flow tray for feeding the solids-laden drilling fluid to a first line and to a second line, the first line to feed the loaded drilling fluid of solids to the first sieve assembly and the second conduit feeding the solids-laden drilling fluid to the second sieve assembly, characterized in that the second conduit comprises a plurality of second conduit openings for dividing the feed of the solid laden drilling fluid and at least one discharge opening for dispersing the solid laden drilling fluid over a second screen assembly.

The VSM MultiSizer and PCT Publication No. WO 2010/150020 shows an overflow weir as a method of inducing parallel flow through the screen. The publication GB No. 2 055 597 shows as a method to increase the yield, the distribution of the flow over two sieve covers on different levels to make simultaneous processing possible.

Vibrating screens work to remove solids from the fluid that it processes and tests, they have shown that due to these solids the previous method of flow separation can lead to different properties

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of the fluid that is processed at any level. This then leads to different processing efficiencies and consequently to different yields.

Preferably, the first conduit has a first conduit opening positioned between the plurality of openings in the second conduit of the second conduit. Advantageously, the vibrating screen further comprises a first additional conduit opening, the first conduit opening and further a first conduit opening interspersed with the plurality of second conduit openings of the second conduit. Advantageously, the vibrating screen further comprises a multiplicity of first conduits each having a conduit opening where the multiplicity of the first conduit openings are interspersed with the plurality of the second conduit openings of the second conduit.

Preferably, the solid laden drilling fluid flows along the flow tray in one flow direction, the flow tray has a width of the flow tray substantially transverse to the flow direction, at least a first duct opening placed through a first portion of the width of the flow tray and the second duct opening placed through a second portion of the width of the flow tray, the first portion is not

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overlap with the second portion. ____ ______

Advantageously, at least a first conduit opening is a plurality of first conduit openings, and at least the second conduit opening is a plurality of second conduit openings. Preferably, the solid laden drilling fluid flows along the flow tray in a flow direction, the plurality of the first conduit openings interspersed with the plurality of the second conduit openings, the plurality of first and second openings of the duct positioned substantially perpendicular to the flow direction.

Advantageously, the flow tray has a feed end and a discharge end, the first and second conduit openings positioned at the discharge end of the flow tray. Preferably, the flow tray has a floor and at least one of the first and second conduit openings is flat with respect to the floor of the flow tray. Advantageously, the other of the first and second conduits has a flat conduit opening relative to the floor of the flow tray. The solid laden drilling fluid therefore does not pass over a landfill and the solid laden drilling fluid is divided through the first and second screen covers with a uniform consistency. An overflow from a

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX338439B_D0016.tif" />

landfill tends to contain more fluid and solid &amp; e-uia_dejiaÍda¿. low and the fluid left under the landfill tends to contain high-density solids, which tend to be sharp and aggressive, which wear away the sieved material quickly. It is advantageous for screen assemblies to wear evenly, so that all screens can be changed at one time, reducing downtime of the vibrating screen. Preferably, the conduit opening is in the form of a flat opening in the floor of the flow tray. Advantageously, the duct opening is perpendicular to the floor of the flow tray, the duct opening defined by a perimeter. Preferably, at least a portion of the perimeter is flat with the floor of the flow tray, so that all of the solid laden drilling fluid passes through the conduit openings and is not trapped on the flow tray.

Advantageously, the flow tray further comprises a valve for directing the solids-laden drilling fluid to one of at least a first screen cover and at least the first and second conduit openings. Preferably, the flow tray has at least one gate opening therein and the valve is a gate valve comprising a gate tray slideable from the closed position that closes fully

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S &lt;:?; · The gate opening to a closing position - La. gate opening.

Preferably, the basket further comprises a pre-removal separation screen cover to receive a pre-removal separation screen to remove large solids from the solid-laden drilling fluid, such that in use the solid-laden drilling fluid flows from the Even on the flow tray and the large solids pass over the preliminary elimination screen. Preferably, the basket further comprises a fourth sieve cover, which may extend in parallel with either or both of the upper and lower sieve cover, or may be used with a sieve having a finer cut-off point for auxiliary graduation of solids in the solid-laden drilling fluid. Advantageously, the large solids pass over the preliminary screen to one of: a tank; and a channel. Preferably, the channel comprises a screw conveyor that moves the solids into a cooper of a solids transport apparatus, such as a positive pressure pneumatic transport apparatus.

Preferably, at least a first sieve cover has a flow pan for the sieved fluid below it to collect and guide the fluid from

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL sieving drilling. Advantageously, at least one sieve-covered year has a sieve fluid flow tray underneath it for collecting and guiding the sieved drilling fluid. Preferably, the basket further comprises a discharge conduit for directing the screened drilling fluid from the screened fluid flow tray to a sludge collector positioned below the basket.

Preferably, at least a first 10 sieve cover is an upper sieve cover and at least a second sieve cover is a lower sieve cover, the lower sieve cover is at least a part of which is placed under the cover. of superior sieves. Advantageously, at least a first sieve cover is an upper sieve cover and at least a second sieve cover is a lower sieve cover, the lower sieve cover is placed completely below the upper sieve cover. Advantageously, a vibrating screen, as claimed in any preceding claim, wherein the lower sieve cover has an imprint or area of ​​the lower sieve cover and the upper sieve cover has an imprint or area of ​​the upper sieve cover, the footprint or area of ​​the lower sieve cover placed entirely below the footprint or area of

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<img file="MX338439B_D0020.tif" />

the top sieve cover. Preferably such that both of them fit within the same basket and cover substantially the same area as each of the others.

Preferably, the basket further comprises a trough, wherein at least a first screen cover has a solids discharge end and the trough is placed under it to receive the solids. Preferably, the trough is made of a composite material, although it can be made of metal foil or other metal or a plastic material. Preferably, the vibrating screen further comprises a sludge collector placed under the basket, the trough positioned to feed the solids into the sludge collector.

Advantageously, the basket further comprises a jet application nozzle positioned to apply a jet of the sieved drilling fluid to the tundish to facilitate the flow of solids therethrough. Preferably, the basket further comprises a flexible conduit, the solids flowing through the trough to the flexible conduit and to the sludge collector. The flexible conduit preferably leads from a side wall of the basket to a sludge collector placed underneath it, the flexible conduit allows the basket to isolate the basket from the base to prevent

-λ rHVf »» £ í&gt; AD ί 'NODSTJiiAt vibrations pass to the base.

Preferably, the basket further comprises a trough and a divider plate, wherein at least a first screen cover has a solids discharge end and the trough is placed below it, the divider plate to guide the solids to the trough. Advantageously, the basket further comprises a trough and a divider cover, where at least a first sieve cover has a discharge end for the solids and the trough is placed under it, the divider cover to inhibit the flow of the solids towards the trough. Preferably, the vibrating screen further comprises one of a tub and a channel, where the dividing cap guides the solids into one of the channel and the tub.

Preferably, at least a first screen cover comprises a left-hand screen cover and a right-hand screen cover. Advantageously, at least a second screen cover comprises a left-hand screen cover and a right-hand screen cover.

Advantageously, the basket has a feed end and a solids discharge end, at least a first screen cover positioned at an uphill angle from the horizontal of the basket feed end to the solids discharge end.

IMPI

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY

<img file="MX338439B_D0021.tif" />

Preferably, the first and second decks are placed at an uphill angle of between three and twelve degrees and even more preferably seven degrees. Advantageously, the angle of the basket can be adjusted to alter the angle of at least the first and second sieve covers. Alternatively, at least the first and second sieve covers are positioned to be horizontal.

Preferably, the vibrating screen further comprises at least a first screen assembly in at least a first screen cover and at least a second screen assembly in the second screen cover. Advantageously, the first sieve assembly has a sieved material thereon and the second sieve assembly has a sieved material thereon, wherein the sieved material of the first sieve assembly is the same as the sieved material of the second sieve assembly to provide the same cut point. The vibrating screen is more likely to operate in a parallel mode with this arrangement. Parallel mode tends to be used when large volumes of drilling fluid are required in a drilling operation, such as when drilling a large diameter hole, which normally occurs when drilling the first upper portion of the wellbore.

Alternatively, the first sieve assembly

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX338439B_D0022.tif" />

it has a sieved material thereon and the second sieve assembly has a sieved material thereon, where the sieved material of the second sieve assembly is finer than the sieved material of the first sieve assembly to provide the different cut points . The vibrating screen is most likely operating in a serial mode with this arrangement.

Preferably, the vibrating screen further comprises a fixed base, the basket suspended from the base on at least one spring, the basket further comprises a vibrating apparatus for vibrating the basket and at least the first and second sieve covers placed therein. .

In the prior art, the use of a landfill initiates a separation function with respect to solids. By and large, the largest and heaviest solids go to the bottom immediately while on the top deck and only the smallest and lightest solids are carried by the flow upstream of the weir onto the bottom deck. Depending on the quantities of these dimensioned solids, an uneven flow regime can occur. If most of the solids are large and heavy then the top sieve level will process most of the solids and suffer from inefficient screening, reduced performance, and increased wear.

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Alternatively, if the volume of the smaller, lighter solids is large, then the load on the bottom cover can be substantially increased again leading to inefficient screening, reduced performance, and increased wear.

Preferably, the divided flow could be 50:50 with respect to any level of the cover and the fluid surfaces could remain similar so that the efficiencies of the sieves are equalized, the present invention offers this facility and a means to derive it when requires serial / serial screening.

The use of a divider gate is again proposed to facilitate switching modes between parallel and series operations. By retracting the gate in the flow tray below the preliminary separation cover, the drilling fluid loaded with the preliminarily separated solids flows from the preliminary separation tray to the upper primary cover consequently inducing only serial operations. By inserting the divider gate the drilling fluid loaded with the preliminarily separated solids is guided into the posterior sieves of the screen which is divided into a number of spatially spaced cavities. The cavities alternate between the fluid guide to the

<img file="MX338439B_D0023.tif" />

main upper cover and finiHn guide up-to the secondary lower cover. Eight cavities are shown but the number of cavities can be varied, reducing the number could make the separation function less efficient while increasing the number could be a more exact division in volume. The divider gate is configured such that the fluid and solids that are carried are able to flow across the full width of the screen thus leading to a 50:50 probability of being introduced into either a primary feed cavity or a secondary feed cavity.

The inventors have observed that a vibrating screen works to remove solids from the fluid it processes and testing in the prior art methods of flow division can lead to different properties of the fluid being processed at any level.

This then leads to different processing efficiencies and consequently to different yields.

In accordance with the present invention, the height of the weir within the rear working duct will be located such that overflow from the top deck is eliminated and all excess flow will be guided to the bottom deck such that the operator you just need to focus on flow rate control based on zero fluid discharge from the

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DC LA TT.Oe'ÍSIJaD industrial bottom cover. The height of the overflow weir is set to ensure that excess flow is directed to a bottom screen rather than completely flooding the screen and losing fluid from the screen discharge, typically the weir is set at a height corresponding to an area length of about 300 mm.

The present invention also provides a method of controlling a vibrating screen comprising a base, a basket isolated from the base, the basket comprising a preliminary separation cover having a preliminary separation screen, an upper cover having a sieve assembly. and a bottom cover that has a fine sieve assembly, the top cover is fed with the pre-separated solids-loaded drilling fluid from a feed tray, the top sieve cover has a feed end and a solids discharge end, characterized in that the upper cover comprises a first conduit to feed the drilling mud loaded with the solids preliminarily separated to the upper cover and a second conduit to feed the separation fluid loaded with the solids preliminarily separated to the lower cover and a weir located in the feed end, the method comprises the steps of forming a lake of the

MEXICAN INSTITUTE OF THE industrial PKLWEOAD

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drilling loaded with separated solids -p^ra1 -im-i n = »- rm ^ ni-A over the top deck sieve assembly and the drilling fluid loaded with the preliminarily separated solids, in excess, passing over the weir to the feed end of the fine sieves from the bottom sieve cover. Preferably, this allows an operator to control the screen simply by looking at the bottom deck and to control the acceleration of the screen, the vibrating screen, or other controllable attributes, such as a deck angle in response to observing the solids and / or to the drilling fluid that is discharged from the lower deck.

Preferably, the weir is formed by a plurality of conduits. Advantageously, the plurality of conduits are formed of at least a first perforation fluid feeding conduit loaded with the solids preliminarily separated to the upper cover and at least a second conduit to feed the drilling fluid loaded with the solids preliminarily separated to the bottom cover, the method comprises the steps of passing the drilling fluid loaded with the preliminary separated solids, in excess, above at least a first conduit to the second conduit.

Preferably, the drilling fluid loaded with the preliminarily separated solids passes below the

<img file="MX338439B_D0025.tif" />

<img file="MX338439B_D0026.tif" />

flow tray or at the same level as the flow tray or slightly above the flow tray.

The present invention also provides a vibrating screen comprising a base, a basket isolated from the base, the basket comprising a preliminary separation cover having a preliminary separation screen, an upper cover having a fine sieve assembly and a lower cover. having a finer sieve assembly, the upper sieve cover has a feed end and a solids discharge end, a flow tray to feed the solids-laden drilling fluid to a first conduit and a second conduit, the first conduit to feed the solids-laden drilling fluid to the fine screen assembly, and the second conduit to feed the solids fluid drilling loaded with solids to finer screen assembly, characterized in that a weir is located between the first conduit and the second conduit such that in use when a puddle of drilling fluid loaded with the previously separated solids is formed on the fine screen assembly of the top cover, Drilling fluid loaded with the previously separated solids passes from the first conduit above the weir to the second conduit and over the feed end of the finer sieve assembly in the

<img file="MX338439B_D0027.tif" />

lower sieve cover. -Preferably, the first conduit has a first conduit opening and the second conduit has a second conduit opening, the first and second conduit openings are substantially flat with the flow tray. Alternatively, the first and second duct openings are below the plane of the flow tray. Preferably, the height of the weir is set to allow an area length of between 100mm and 500mm, and even more preferably 300mm above the discharge end of the top sieves. Advantageously, the height of the weir is adjustable, preferably to allow an area length of between 0mm and 1mm and even more preferably between 200mm and 500mm.

Advantageously, the weir is also substantially flat with the flow tray. Preferably, the weir is below the level of the flow tray.

This aspect of the present invention may have some or all of the other features and / or steps in the methods as described in any statement of the invention described herein.

The present invention also provides a method of separating solids from the solids-loaded drilling fluid using a vibrating screen that comprises a Mexican institute.

DE LA PROPIEDAD V industrial S, 's covered with sieves, the method comprises the steps of flowing the solids laden drilling fluid over the flow tray, through at least the first and second conduit openings at least into the first and second conduits, at least a first conduit that directs the solid laden drilling fluid to at least a first screen cover and at least a second conduit that directs the solid laden drilling fluid to the second screen cover.

The present invention also provides a vibrating screen to separate solids from the solids-laden drilling fluid, the vibrating screen comprises a basket having a preliminary separation screen cover, at least a first screen cover and at least a second cover of screens, wherein the basket further comprises a flow tray placed between the preliminary separation screen cover and at least a first screen cover, and a plurality of first conduits and a plurality of second conduits, the first plurality of first conduits for directing the solids-laden drilling fluid to at least a first screen cover and the second plurality of conduits for directing the

<img file="MX338439B_D0028.tif" />

solid-laden drilling fluid — a — l · * —eegimda.

sieves cover.

Preferably, the flow tray has at least one gate opening therein of a gate valve comprising a gate tray slidable from a closed position that completely closes the gate opening to an open position that opens the gate opening. the gate allowing solids-laden drilling mud to flow through it. Preferably, the gate opening is positioned upstream of the plurality of first and second conduits, such that none or only a small amount of the solid-laden drilling fluid could reach the plurality of the first and second conduits.

Advantageously, the basket further comprises a screened fluid flow tray positioned below at least a first screen cover, the screened fluid flow tray has a selector opening therein and a selector gate valve for opening and selectively closing the selector opening to selectively allow the sieved drilling fluid to flow therethrough on at least a second screen cover.

The present invention also provides a vibrating screen to separate solids from drilling fluid.

<img file="MX338439B_D0029.tif" />

laden with solids, the vibrating screen comprises — a hass. a basket isolated from the base, the basket comprises a preliminary separation cover, at least a first cover and at least a second cover, at least a first cover having a feed end and a solids discharge end, a trough placed in the basket at the discharge end of at least a first cover and a divider plate to selectively inhibit and allow solids to be discharged from the discharge end of at least a first cover into the trough.

Preferably, the vibrating screen further comprises a flexible conduit leading from the tundish to a sludge collector placed under the basket to collect the sieved drilling fluid.

The present invention also provides a method of separating the solid laden drilling fluid with a vibrating screen, the vibrating screen comprises a base, a basket isolated from the base, the basket comprises a preliminary separation cover having a preliminary separation screen , at least a first cover having a sieve assembly and at least a second cover having a fine sieve assembly, at least a first cover has a feed end and a solids discharge end, a trough placed in the

IMPI r, ¿3

INSTITUTO MEXICANO OE LA PROPIEDAD industrial basket at the discharge end of at least a first cover and a divider plate, the method comprises the steps of making the solid-loaded drilling mud flow on the preliminary separation screen, large solids pass over the preliminary separation screen and the solids-laden drilling fluid passes through the preliminary separation cover to the screen assembly of at least a first screen cover, the dimensioned solids pass over the screen assembly towards the trough guided by the dividing plate towards the trough.

Preferably, the method further comprises the step of flowing the sized solids from the trough to a sludge collector below the basket, the sludge collector also collects the drilling fluid sieved by the fine mesh sieves, from at least a second sieves cover. Advantageously, the flow of the dimensioned solids is facilitated by a jet of the drilling fluid.

This aspect of the present invention may have some or all of the other features and / or steps in the methods as described in any statement of the invention described herein.

For a better understanding of. the present invention, reference will now be made, by way of example, to the attached figures, in which:

MEXICAN INSTITUTE Ί? Ζ · 6

DF THE PROPERTY CV.

INDUSTRIAL Figure 1 shows a perspective view of an apparatus for separating solids from solids-laden drilling mud;

Figure 2A is a schematic cross-sectional view of an apparatus for separating and sizing solids from solids-laden drilling mud, the apparatus comprising a base and a basket;

Figure 2B is an end view of the basket shown in Figure 2A with the sieve assemblies therein;

Figure 3 is a sectional side view of a basket of a vibrating screen according to the present invention;

Figure 3A is an enlarged view of a part of the basket shown in Figure 3, with the parts in a first mode of operation;

Figure 3B is an enlarged view of a part of the basket shown in Figure 3, with the parts in a second mode of operation;

Figure 3C is an end view of the basket shown in Figure 3 with the sieve assemblies therein;

Figure 4 is a perspective view of a part of the basket shown in Figure 3A with the hidden parts shown, in the first mode of operation.

MEXICAN INSTITUTE EU PROPERTY

INDUSTRIAL indicating the direction of flow from the solids-laden drilling mud to a top primary screen deck;

Figure 5 is a perspective view of a part of the basket shown in Figure 3A, with the hidden parts shown, in the first mode of operation indicating the direction of flow of the solid loaded drilling mud to a primary screen cover inferior;

Figure 6A is an enlarged cross-sectional view of a basket solids dividing apparatus shown in Figure 3, in the first mode of operation;

Figure 6B is an enlarged cross-sectional view of a basket solids dividing apparatus shown in Figure 3, in the second mode of operation;

Figure 7 is a sectional end view of a vibrating screen comprising the basket shown in Figure 3, showing the details of a solids dividing apparatus; and Figure 8 is a side view of the vibrating screen shown in Figure 7 placed on a sludge collector, with some hidden parts shown.

Figure 1 shows an apparatus for separating the

<img file="MX338439B_D0030.tif" />

solids from a loaded dp nólidog drilling mud, - generally referred to as a vibrating screen and identified here by reference H. The vibrating screen H comprises a base D having an open bottom R positioned above a collection receptacle (not shown) to receive the sieved drilling mud. A basket B is placed on the springs C on the base D. A vibrating apparatus E is placed on top of the basket B. The vibrating apparatus E comprises an electric or hydraulic motor M that rotates the weights of the off-center masses hidden within the liner S, which induce movement in the basket D. Some upper, intermediate upper, lower intermediate and lower sieve assemblies Al A2, A3, A4 are placed in basket D and fixed to it on rails (not shown) so that the movement induced in the basket is transferred ¹ to Al, A2, A3, A4 sieve assemblies. The solid laden drilling fluid is fed to the screen assemblies A1-A4 from a feed chamber F at a feed end of the apparatus. The induced movement in the A1-A4 screen assemblies facilitates the separation of the solids from the drilling mud. The screened drilling mud passes through the screen assemblies into the collection receptacle (not shown) and solids creep along

IMPI

INSTITUTO MEXICANO DE LA PROPERTY INDUSTRIAL the A1-A4 screen assemblies with respect to a discharge end P of the vibrating screen and to a tub, channel and other cutting material transfer devices (not shown).

Figures 2A and 2B show a vibrating screen 10 having a base 20 of a basket 30 placed thereon on springs (not shown). The basket 30 comprises a preliminary separation cover 11, an upper primary cover 12 and a lower primary cover 13. The upper primary cover 12 has a left-hand side 12a and a right-hand side 12b. The lower primary cover has a left hand side 13a and a right hand side 13b. The solid-laden drilling fluid is fed to a feed end of the vibrating screen 14 from a feeder (not shown) on a preliminary separation screen 15 placed in the C16-shaped channels of the preliminary separation cover 11. A Expandable pneumatic chamber 17 is placed on top of the C-shaped channels 16 to secure the preliminary separation screen 15 therein. Alternatively, a wedge can be used to secure the preliminary separation screen 15 in the C-shaped channels 16. The preliminary separation screen 15 comprises a screen 18 having relatively large openings to inhibit large particles from passing through it. until

<img file="MX338439B_D0031.tif" />

IMPI

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY

<img file="MX338439B_D0032.tif" />

primary covers but allows something dS '' luy ¹ súlidus — and drilling mud pass through them. The preliminary separation cover 11 and the screen 15 thereon are positioned at an upward slope of approximately one degree from the horizontal, although the preliminary separation screen 15 and the preliminary separation cover 11 can be placed horizontally, slightly downhill or at a slightly larger uphill angle. Vibrating apparatuses 16a attached to basket 30 induce movement therein. The movement facilitates the separation of the large solids from the solid laden drilling mud and induces movement in the large solids along the preliminary separation screen 15 from the feed end 14 to the discharge end 19 of the vibrating screen. Large solids can be captured in a channel or on transport media and further processed or used in other operations. The solids-laden drilling fluid passing through the preliminary separation screen 15 falls onto the flow tray 21 that directs the solids-laden drilling fluid to the feed end 14 of the sieve assemblies 22a and 22b on the primary cover top 12. A weir 23 is placed at the feed end of the primary cover 12 to retain the solid laden drilling fluid. If he

IMPI

MEXICAN INSTITUTE OF INDUSTRIAL RROPIEDAP

<img file="MX338439B_D0033.tif" />

The level of the solid laden drilling fluid rises beyond the height of the weir 23, the solid laden drilling fluid passes above it into a conduit 23 and up to the screen assemblies 25a and 25b in the lower primary screen cover 13. The screen assemblies 22a, 22b and 25a and 25b are preferably of the same type and have the same screen mesh thereon.

A gate valve 26 in the form of a sliding pan is in a closed position to extend over the vibrating screen in a parallel manner. The screened drilling mud falls through the screen assemblies 22a and 22b in the top screen cover to a flow pan 27 and above the closed gate valve 26. And into a conduit 28 that runs parallel to the conduit 24 . However, conduit 28 leads to the bottom of the basket and directly into the collection receptacle (not shown) below it. The solids fall out of the discharge end 31 of the upper sieve cover 12 and the discharge end 32 of the lower sieve cover 13 and into a tub or other conveying apparatus to transport the solids for further processing or reuse.

Gate valve 26 can be retracted to allow drilling mud to be screened by llVIJr 1

INSTITU: O MEXICANO pf. the pkokide i&gt; O »» ~; zS

INDUSTRIAL - »» sieve assemblies 22a and 22b in the e-uteierfca, ..... of · upper sieves 12 are additionally sieved by the assemblies of sieves 25a and 25b on the lower sieve cover 13. The vibrating screen It thus extends in a serial mode. In this situation, it is preferable to use a finer screen mesh in screen assemblies 25a and 25b than the screen mesh used in screen assemblies 22a and 22b. Drilling mud sifted by the screen assemblies 22a and 22b in the top screen cover 12 flows into the flow pan 27 and into a conduit 29, which directs the screened drilling mud onto the feed end of the filter assemblies. sieves 25a and 25b in the lower sieve cover 13. The sized solids fall out of the discharge end 31 of the top screen cover 12 into a conveyor apparatus (not shown) to be transported and mixed in a fresh batch of the drilling mud for recycling. These dimensioned solids are used to block fractures in the formation as described here above. The solids discharges from the discharge end 32 of the lower sieve cover 13 are transported in a separate conveyor apparatus or added to a tub for further processing or to be used for other purposes.

With reference to Figures 3, 3A, 3C, 4 and 5 there

IMPI

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY shows a basket 100 of a vitoratoriá sieve. The basket 100 comprises a preliminary separation cover 111, an upper primary cover 112 and a lower primary cover 113. The upper primary cover 112 has a left-hand side 112a and a right-hand side 112b. The lower primary cover 113 has a left hand side 113a and a right hand side 113b. The solid laden drilling fluid is fed to a feed end of the vibrating screen 114 from a feeder (not shown) to a preliminary separation screen 115 placed in the C-shaped channels 116 of the preliminary separation cover lli. An expandable pneumatic chamber 117 is placed in an upper part of the C-shaped channels 116 to secure the preliminary separation screen 115 therein. Alternatively, a wedge can be used to secure the preliminary separation screen 115 in the C-shaped channels 116. The preliminary separation screen 115 comprises at least one layer of the screen material 118, such as a wire mesh having relatively large openings to prevent large particles from passing through it to the upper and lower primary covers 112 and 113 , but allowing some of the solids and drilling mud to pass through it. The preliminary separation cover 111 and the separation screen

<img file="MX338439B_D0034.tif" />

IMPI

INSTITUTO MEXICANO E&gt; £ LA PROP / tOAL · 'INDUSTRIAL preliminary 115 on it are placed - at · an uphill slope of approximately one degree from horizontal, although the preliminary separation screen 115 and the preliminary separation cover 111 they can be placed horizontally, slightly downhill or at a slightly larger uphill angle. Vibrating apparatus 116a attached to basket 100 induces movement therein. Movement facilitates separation of large solids from the solids-laden drilling mud and induces movement of the large solids along the preliminary separation screen 115 from the feed end 114 to the discharge end 119 of the vibrating screen. . Large solids can be captured in a tank, channel or on a transport medium (not shown) and further processed or used in other operations. The solids laden drilling fluid passing through the preliminary separation screen 115 falls onto a flow tray 121 which directs the solids laden drilling fluid onto a closed distribution gate valve in the form of a discharge gate tray. sliding tray distribution 101, and as shown in Figures 4 and 5, through eight openings 102a, 102b, 102c, 102d and 103a, 103b, 103c and 103d of the conduit of a collector 104 placed between the side walls 105 and 106 of the basket 100. Preferably, the

IMPI · * - * - ^T -S. -ii. Hee Mexican Institute of Industrial Property

<img file="MX338439B_D0035.tif" />

eight openings 102a, 102b, 102c, 102d and 103a, TÜ3B, 103c-y

The conduit 103d are located at the same level as or slightly below the flow tray 121 and the distribution gate tray 101. The openings 102a, 102b,

102c, 102d, and 103a, 103b, 103c, and 103d can be positioned vertically on manifold 104, with openings 102a, 102b, 102c, 102d, and 103a, 103b, 103c, and 103d each having a substantially level bottom edge with, or slightly below the distribution gate tray 101. Solids laden drilling fluid flows in approximately equal amounts through conduit openings 102a through 102d into conduits 107a through 107d and through openings 103a through 103d into conduits 108a through 108d. Approximately one eighth of the flow of the solid laden drilling fluid passes to each opening 102a to 102d and 103a to 103d. The conduits 107a and 107b lead to the respective discharge outlet 109a and 109b, discharging the solid laden drilling fluid onto a feed end of the sieves 122a of the upper primary cover 112. The conduits 107c and 107d lead to the outlets of the discharge respective 109c and 109d, discharging the solid laden drilling fluid onto a feed end of the sieves 122b of the upper primary cover 112. Ducts 108a and 108b merge into the tacra.

<img file="MX338439B_D0036.tif" />

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX338439B_D0037.tif" />

conduit 110a and conduits 108c and 108d fuse into conduit 110c, discharging the solid laden drilling fluid through the discharge opening HOd over the feed ends of the screens 125a and 125b respectively of the lower primary cover 113.

Drilling mud sifted through screens 122a and 122b falls through screens 122a and 122b onto a flow pan 127 and flows down along the selector gate trays 126a and 126b, respectively, and into the fluid discharge 124a, 124b and 124c. Ξ1 sieved drilling fluid passes through openings 124a and 124b into fluid discharge duct 124d and is directed to a sludge catcher 157 (see Figure 8), sieved drilling fluid also passes through opening 124c and into a fluid discharge conduit 124e which also directs the sieved drilling fluid to the sludge catcher 157 (see Figure 8) positioned below the

<td colspan="2">basket 100.</td><td rowspan="2">fluid of</td><td rowspan="2">drilling loaded with</td><td rowspan="2">solids</td>

<td></td><td>The</td>

<td>sieving</td><td>by</td><td>the sieves</td><td>125a and 125b falls through</td><td>of the</td>

<td>sieves</td><td>125a</td><td colspan="2">and 125b on a flow tray</td><td>128 that</td>

discharges the sieved drilling fluid through opening 129 into the sludge collector (not shown) or the collection receptacle (not shown).

IMPI

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY

The solids sieved by the sieves 122a and 122b and the sieves 125a and 125b are discharged over the discharge end of the solids 13 0 and 131 respectively and into a channel, tank or other apparatus for transporting or collecting the solids.

In this parallel mode of operation, both upper and lower screen covers are used to screen the same solid-laden drilling fluid, which simply had large solids removed by the preliminary separation screen 115. Therefore in this parallel mode, sieve assemblies 122a, 122b and 125a and 125b are preferably of the same type and have the same sieve mesh thereon.

With reference to Figure 3B, a serial mode of operation is shown. The distribution gate tray 101 and selector gate trays 126a and 126b are retracted. The distribution gate tray 101 is placed on a rail 132. Distribution gate tray 101 is retracted along rail 132 by activation of an actuator (not shown), which may be pneumatic, hydraulic, electrical, or mechanical, and may be activated by a switch (not shown) on the vibrating screen or by remote control from a control installation. Trays 126a and 126b of

<img file="MX338439B_D0038.tif" />

<img file="MX338439B_D0039.tif" />

the selector gate are installed r7V Iuj crnj^{, 1Q1t}Respective TF of lanes 133a and 133b. Selector gate trays 126a and 126b are simultaneously retracted along track assemblies 133a and 133b by activation of an actuator (not shown), which may be pneumatic, hydraulic, electrical, or mechanical and may be activated by a switch (not shown) on the vibrating screen or by the remote control from a control installation.

In this serial mode, the distribution gate tray 101 and selector gate trays 126a and 126b are retracted revealing an opening 134. The solid laden drilling fluid flows through opening 134 onto a divider tray on top 135 and on a feeding end of sieves 122a and 122b on top sieve cover 112. The sieved drilling fluid flowing through the sieves 122a and 122b flows over the flow tray 127 and through an opening 13 6 revealed by the retracted selector gate trays 126a and 126b, above a lower divider tray 137 to a feeding end of the screens 125a and 125b on the cover of the lower screens 113.

In this serial mode of operation, screens 122a and 122b on top screen cover 112 are

<img file="MX338439B_D0040.tif" />

<img file="MX338439B_D0041.tif" />

used to first cut to remove large solid wood and sieves 125a and 125b on the lower sieve cover 113 are used to make a finer cut. Thus, in series mode, screens 125a and 125b will be of a finer mesh size than screens 122a and 122b. The solids removed by the sieves 122a and 122b are therefore dimensioned solids, which can be reused in the sieved drilling mud. Sized solids are useful, inter alia, as drill hole reinforcing materials to block or fill fractures in the borehole walls when the drilling mud is circulated.

In use, a puddle of solids-laden drilling fluid, preliminarily separated, may form on the sieves 122a and 122b of the upper primary sieve cover 112. It should be noted that the upper part of the solids-laden drilling fluid, separated preliminarily, it will move up to the conduits 107A-D substantially in line with the top of the puddle on the top primary screen 112. Preliminary separated solids-laden drilling fluid will pass over weirs 200A to 200G from conduits 107A-D into the conduits

108A-D and therefore the preliminary separated solids-laden drilling fluid will flow from

<img file="MX338439B_D0042.tif" />

IMPI

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY the same on one end of the imfintac-ion gives the lower primary cover 113.

Figure 6A shows in cross section the solids discharge end of basket 100, taken through one side 112a. The solids are transported uphill along the upper surface of the screens 122a and 122b by a vibratory motion induced in the screens 122a and 122b by the vibrating apparatus 116. Solids fall from sieves 122a and 122b onto respective, parallel divider plates 150 (only one side plate 112a is shown) fitted on a trough 151 and a trough 151a. The parallel divider plate 150 is angled at approximately twenty-five degrees from the horizontal to directly facilitate the removal of the solids from the basket into a tub, channel, or some means of transporting the solids. Parallel divider plate 150 is equipped on trough 151 preferably when the vibrating screen is in the parallel mode of operation.

Figure 6B shows the divider plate 150 removed and replaced with the 152 and 152a series divider plates installed at the end of the basket 100. The 152 and 152a series divider plates are equipped at the discharge end of the basket 100 to direct the solids from sieves 122a and 122b towards troughs 151 and 151a. Solids flow through troughs 151 and 151a, which

<img file="MX338439B_D0043.tif" />

they have a floor 153, 153a that slopes towards the respective openings 154 and 154a on the sides 105 and 106. The flexible conduit connectors 155 and 155a lead from the openings 154 and 154a respectively to the channels 156 and 156a of the sludge collector in a base 158. Basket 100 is isolated from base 158 on four springs 159 and 159a (only two are shown). The sludge collector channels 156 and 156a lead to the sludge collector 157 under the basket 100. The generally smaller solids that are discharged from the discharge end 131 of the lower sieve cover 113 fall into the tank, channel, or other apparatus for transporting the solids for further disposal or processing for industrial or construction use. . Accordingly, the sized solids between the preliminary separation cover and the upper primary screen are returned to the screened drilling mud in the sludge catcher 157 for recycling to a borehole. The flow of the solids through the troughs 151 and 151a is facilitated by the fully screened drilling fluid that is applied as a jet through the jetting nozzles 16 0 and 160a, respectively. The jet application nozzles are connected to drill mud supply hoses (not shown) and a pump (not shown). 1162 nozzles for application of a

<img file="MX338439B_D0044.tif" />

INDUSTRIAL blasting are also provided in the channels 1156 of the sludge collector after coupling 11156 of the flexible conduit to facilitate the flow of solids to the sludge collector 1157.

It is noted that in relation to this date, the best method known by the applicant to put the aforementioned invention into practice is the one that is clear from the present description of the invention.