WO2018071614A1

WO2018071614A1 - Screen pulse system pressure differential generating device

Info

Publication number: WO2018071614A1
Application number: PCT/US2017/056245
Authority: WO
Inventors: Evan FRAZIER; Richard Bingham
Original assignee: M-I L.L.C.
Priority date: 2016-10-12
Filing date: 2017-10-12
Publication date: 2018-04-19

Abstract

Systems and methods for generating a pressure differential below a screen in a vibratory separator to urge a substance being separated to pass through the screen of the vibratory separator are disclosed. Pressurized fluid is supplied to a pressure differential generator to generate a pressure differential across a screen of the vibratory separator. A securement assembly secures a tray to the vibratory separator. The tray has a drain separate from a pressure differential generator. An interior of the drain and an interior passage of the pressure differential generator can connect at a location in which pressurized fluid entering the pressure differential generator does not cause detrimental effects to the substance being separated.

Description

SCREEN PULSE SYSTEM PRESSURE DIFFERENTIAL GENERATING DEVICE

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U .S. Provisional Patent Application No. 62/407,437 entitled "SCREEN PU LSE SYSTEM PRESSURE DI FFERENTIAL GEN ERATI NG DEVICE" filed on October 16, 2016 which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] Various industries, such as oil and gas, mining, agriculture, and the like utilize equipment and/or methods to separate fluid from materials. For example, in the oil and gas industry, oilfield drilling fluid, often called m ud, drilling mud, or drilling fluid, serves multiple purposes. Among its many functions, the drilling mud acts as a lubricant for a drilling bit and increases the rate of penetration of the drilling bit. Drilling fluid may also cool the drill bit and provide support for a wellbore during the drilling process. Drilling fluid is pumped through a bore of the drill string to the drill bit where the drilling fluid exits through various nozzles a nd ports, lubricating the drill bit.

[0003] Another purpose of the drilling fluid is to carry the cuttings away from the drill bit to the surface. After exiting through the nozzles, the spent fluid returns to the surface through an annulus formed between the drill string and the drilled wellbore. The returned drilling mud is processed for continued use. The drilling fluid exiting the borehole from the annulus is a slurry of formation cuttings in drilling fluid, and the cutting particulates must be removed before the drilling fluid is reused.

[0004] I n order to remove solid particulates, such as cuttings, from the drilling fluid, many in the oil and gas industry use what is known as a shaker. A shaker may also be called a shale shaker, a vibratory separator, or a gyratory sifter. A vibratory separator may be a vibrating, sieve-like table upon which returning, used drilling fluid is deposited and through which substantially cleaner drilling fluid emerges. A vibratory separator is an angled table with a generally perforated filter screen bottom. Returning drilling fluid may be deposited at the top or inlet end of the shaker. As the slurry moves toward a discharge end, which is higher than the inlet end, the fluid may fall through the perforations to a reservoir below, thereby separating the solid particulate material that is unable to pass through the filter screen.

[0005] Screens used with shakers are placed in a horizontal fashion on a horizontal support within a basket or tray in the shaker. The shaker imparts a rapidly reciprocating motion to the basket and screens. Material from which particles are to be separated is poured onto a back end of the vibrating screen and are conveyed along the shaker toward the discharge end of the basket.

[0006] In some shakers, a fine screen cloth is used with the vibrating screen. The screen has two or more overlaying layers of screen cloth and/or mesh. Layers of cloth and/or mesh are bonded together and placed over a support. The frame of the vibrating screen is suspended and/or mounted on a support and vibrates by a vibrating mechanism to create a flow of trapped solids on top surfaces of the screen for removal and disposal of solids.

[0007] Shakers include one or more sets of screens in a series or parallel configuration between the inlet and the discharge end. Shakers may include a system of eccentric weights. For example, a gyratory sifter may include a top weight and a bottom weight. The top weight is coupled to a motor, causing the top weight to rotate in a plane that is close to the center of the mass of assembly. This causes vibration and movement of the screens in the horizontal plane, which causes material input to the screen surface to spread across the screen from the middle to the periphery of the screen. Such movement encourages material too large to pass through the screen to be output and thus removed from the screen surface. A bottom eccentric weight rotates below the center of mass and create a tilt on the screen surface. The imposition of a tilt on the screen surface causes vibration in a vertical and tangential plane. Such movement induces particles smaller than the mesh size to pass through the screen surface at a more rapid pace and encourages particles only slightly smaller than the mesh size to find the correct alignment for passing through the screen, thus increasing turnover. Horizontal or vertical motion is amplified through spring assemblies.

BRIEF DESCRIPTION OF THE FIGURES

[0008] Figures la and lb are a top perspective views of a shaker configured to support a pressure differential system according to embodiments of the present disclosure. [0009] Figure 2 shows a perspective view of an embodiment of a tray and support unit with the swing brackets in a folded configuration according to embodiments of the present disclosure.

[0010] Figure 3 shows a perspective view of an embodiment of a tray and support unit with the swing brackets in a standing configuration according to embodiments of the present disclosure.

[0011] Figure 4 is a perspective view of the shaker and the support unit showing how the support unit is inserted into the shaker according to embodiments of the present disclosure.

[0012] Figure 5 is a perspective view of the shaker and support unit after raising the swing brackets according to embodiments of the present disclosure.

[0013] Figure 6 is an illustration according to embodiments of the present disclosure of a tray including a pressure differential generating system mounted to the tray.

[0014] Figure 7 is a perspective view of a pressure differential system according to embodiments of the present disclosure.

[0015] Figure 8 is a perspective view of a pressure differential system according to embodiments of the present disclosure.

[0016] Figure 9 is a side cutaway view conduit, tray, and drain according to embodiments of the present disclosure.

DETAILED DESCRIPTION

[0017] In the following detailed description, reference is made to the accompanying drawings in which similar symbols typically identify similar components unless context dictates otherwise. The illustrative embodiments described herein are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure as generally described herein and illustrated in the Figures may be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

[0018] Figure la is a top perspective view of a basket 22 of a vibratory separator 20 configured to support a pressure differential system according to embodiments of the present disclosure. Figure lb is a perspective view of the vibratory separator 20 with a screen 25 installed. The vibratory separator 20 can be used to separate a first substance from a second substance, such as a fluid or solid particulate from a mixture or a slurry. The vibratory separator 20 may generate force or motion to aid in the separation of the first substance from the second substance, such as by use of vibrational motion in a linear, elliptical, circular or other motion shape. In an embodiment, the vibratory separator 20 may be a shale shaker used to separate drill cuttings from a slurry of drilling fluid and drilling cuttings as appreciated by those having ordinary skill in the oil and gas industry. In many configurations, the basket 22 is separable and movable with respect to a skid 32 as shown in Fig. lb. The screen 25, as shown in Figure lb, can be inserted in the vibratory separator 20 and can be secured to a bed of the basket 22 of the vibratory separator 20. The screen 25 may have apertures that permit the first substance to be separated from the second substance. In the case of drilling fluid and drill cuttings, the apertures may be sized to prevent drill cuttings from passing therethrough and to permit drilling fluid and other weighting or solid particulates to pass therethrough. The first substance, for example, can be prevented from passing through the screen 25 and discharged off an end of the vibratory separator 20. The second substance can be conveyed or moved through the apertures of the screen 25. The first substance and/or the second substance can be captured for further processing and/or re-use. The screen 25 can be secured to the vibratory separator 20 using force applied by a compression system, tension system, pneumatic clamping system, mechanical clamping system, such as by use of wedges, or other mechanism for securing the screen 25 to the vibratory separator 20.

[0019] The vibratory separator 20 can have a frame 30 which supports the screen 25 and/or multiple screens 25. A tray 1 may be secured to the frame 30. The tray 1 can be connected to the frame 30 to draw additional fluid through the screen 25. A device or system for generating a pressure differential across the screen 25 may be connected to and/or in fluid communication with the tray 1. A portion of the substance that may be drawn through the screen 25 can be collected in the tray 1. The frame 30 can have various components such as side walls 32, support bars 6, and cross-support bars 7. There can be any number of cross bars and support bars which can extend in a generally horizontal direction to create a generally flat supporting surface which can support the screen. The fluid that passes through the screen can pass through the support bars 6 and the cross-support bars 7. [0020] A securement assembly 60 permits the tray 1 to secure to the frame 30. In an embodiment, the securement assembly 60 may secure the tray 1 such that the top of the frame 30 is capable of supporting the screen 25. For example, the securement assembly 22 may permit the tray 1 to be positioned below the frame 30. The tray 1 may be positioned under the frame 30 and contact a ledge or lip 50 on the basket 22. The securement assembly 22 can secure the tray 1 to the basket 22 such that movement of the tray 1 with respect to the basket 22 is prevented or limited. Due to motion of the vibratory separator 20, it may be advantageous to prevent movement of the tray 1 against and/or with respect to the basket 22. The securement assembly 60 can be modified to secure to different vibratory separators 20, having different sized and shaped frames.

[0021] The securement assembly 60 may apply a force against the frame 30 of the vibratory separator 20 to secure the tray 1 against the basket 22. In an embodiment shown in Figs. 2-5, the securement assembly 60 has a bracket 2, retention bar 3, and fasteners 4 to secure the tray 1 to the frame 30. The retention bar 3 may move from a first position horizontal to the tray 1 to a second position vertical and perpendicular to the tray 1. As shown in Fig. 4, the tray 1 may be inserted below the frame 30 with the retention bar 3 in the first position. If the tray 1 is inserted below the frame 30 into a predetermined desired location, the retention bar 3 may be moved via the brackets 2 to the second position. In the second position, the retention bar 3 may contact the frame 30 and apply a force against the frame 30. The force may cause the tray 1 to secure to the ledge or lip 50 of the basket 22 of the vibratory separator 20. The fasteners 4 may be extended, forcing the retention bar 3 against the support bars 6 of the vibratory separator 20. The fasteners 4 can be used to secure the retention bar 3 in the second position and/or to adjust the position of the retention bar 3 with respect to the frame 30. The fasteners 4 may, in one or more embodiment, be extendable pints, detents or other types of fasteners, pins or devices as will be appreciated by a person having ordinary skill in the art.

[0022] The tray 1 may be shaped to collect the substance passing through the screen 25. In one or more embodiments, the tray 1 may be shaped to fit within and/or to correspond to the shape of the vibratory separator 20 or its components. The tray 1 may include a gasket 5 for sealing and/or preventing damage to the vibratory separator 20. The gasket 5 may dampen and/or prevent movement of the tray 1 with respect to the lip or ledge 50 of the vibratory separator 20. The gasket 5 may comprise one or more portions about the perimeter of the tray 1. The gasket 5 may provide a fluid seal between the tray 1 and the lip or ledge 50 of the vibratory separator 20 to prevent fluid from moving between the tray 1 and the lip or ledge 50 of the vibratory separator 20. Moving the retention bar 3 to the second position and/or extending the drive bolts 4 the tray 1 can force the gasket 5 against the vibratory separators 20 that may, in one or more embodiments, compress at least partially to form a seal.

[0023] Fig. 6 illustrates a pressure differential generating system 24 connected and/or secured to the tray 1. The tray 1 has a port 12 that can be connected to a fluid source, such as a pressurized fluid source 23. The port 12 may be connected to an inlet 18 of a pressure differential generator 14. The inlet 18 extends from a side of the pressure differential generator 14 into the interior of the body of the pressure differential generator 14. The pressurized fluid source 23 may comprise a gas, such as air, a fluid, such as water or drilling fluid, or a mixture of any liquid or gas or other substance capable of causing the pressure differential across the screen 25 if provided to the pressure differential generator 14. The pressurized fluid source 23 may be provided from the port 12 to the inlet 18 by way of a conduit 80 as shown in Fig. 9.

[0024] The port 12 may be connected to the pressurized fluid source 23 on a side of the tray 1 opposite to the conduit 80. For example, one side of the tray 1 may have a first surface adjacent the frame 30 having the port 12 with the conduit 80, and the other side of the tray 1 may comprise a second surface adjacent an underside of the vibratory separator 20, which in the embodiments shown in Figs. 7 and 8 may have a further conduit or other device (not shown) providing fluid communication to the port 12.

[0025] The pressure differential generator 14 may be any device capable of causing a pressure change across the tray 1 and/or the screen 25. As a non-limiting example, the pressure differential generator 14 may be a conveyor or amplifier, such as described in U.S. Patent No. 5,402,938, which is hereby incorporated by reference. The pressure differential generator 14 may cause the pressurized fluid to pass through the pressure differential generator 14 in such a manner that the substance on the screen 25 and/or any substances, such as air, above the screen 25 may be drawn through the screen 25 at a higher rate, volume or amount than would have been without the pressure differential generator 14. The pressure differential generator 14 may cause additional separation of the first substance from the second substance than without its use. The pressure differential generator 14 may direct the pressurized fluid at an increased velocity, volume, efficiency or rate through its body, such as around an external perimeter of the device. In turn, the movement of the pressurized fluid through the pressure differential generator 14 can draw air and/or the substance through the screen 25.

[0026] The pressure differential generator 14 can be secured to the tray 1 and have an opening or interior passage 16 extending through a body of the pressure differential generator 14. The interior passage 16 can transport the pressurized fluid and/or the substance conveyed through the screen into an area below the tray 1. A hose (not shown) or other conduit may be connected to an exit of the passage 16 of the pressure differential generator 14, such as at an end of the passage 16 opposite the retention bar 3. The interior passage 16 can extend through the pressure differential generator 14 and extend through the tray 1 to a collection unit (not shown), such as below the tray 1. In one or more embodiments, if secured to the vibratory separator 20, the interior passage 16 extends between the tray 1 and the frame 30.

[0027] Depending on the application of the vibrator separator 20, it may be disadvantageous for the substance on the screen 25 to move into the interior passage 16 and interact with the pressurized fluid being supplied to the pressure differential generator 14. For example, the pressurized fluid may atomize or pressurize the substance separated from the screen 25 creating collection problems, composition problems or other undesirable effects. These disadvantages may be most significant if the substance moves into the interior passage 16 at or above the inlet 18. Other reasons for limiting the substance from moving into a top of the pressure differential generator 14 will be apparent to a person having ordinary skill in the art depending on the application.

[0028] The pressure differential generator 14 can extend above the tray 1 to prevent, to substantially prevent or to at least minimize the substance separated from the screen 25 from entering the interior passage 16 of the pressure differential generator 14. The substance separated from the screen 25 may collect on the tray 1 and move into a drain 62. The tray 1 may have the drain 62 positioned adjacent the pressure differential generator 14. The tray 1 may be sloped toward or otherwise shaped to encourage substance moving through the screen 25 to flow into and through the drain 62.

[0029] The drain 62 may have an interior 8 extending into the interior passage 16. In the embodiment shown in Fig. 9, the interior 8 of the drain 62 can connect to the interior passage 16 of the pressure differential generator 14. The pressurized fluid supplied to the inlet 18 via the conduit 80 can move through the pressure differential generator 14 away from the screen 25 and toward the interior 8 of the drain 62. Movement of the pressurized fluid into the pressure differential generator 14 can draw the substance through the screen 25 and further draw the substance through the drain 62. Advantageously, the substance may mix or interact with the pressurized fluid at a distance from the inlet 18 that may minimize or limit atomizing or other undesired effects as previously discussed. The substance falling or conveyed through the screen 25 can collect on the tray 1 without reaching the interior passage 16 of the pressure differential generator 16 or at least the amount of the substance can be drastically minimized.

[0030] Figure 9 is a side cutaway view of the pressure differential generator 14 and the drain 62 according to embodiments of the present disclosure. Connecting the interior 8 of the drain 62 to the interior passage 16 of the pressure differential generator 14 can be advantageous. For example, it can permit the substance from the screen 25 to flow through a bottom of the pressure differential generator 14 and advantageously limit or eliminate misting, atomization or other undesired effects of having the substance pass through the pressure differential generator 14 at the inlet 18 of the pressurized fluid. The pressurized fluid in the pressure differential generator 14 may be travelling at a significantly lower velocity adjacent the drain 62 than at the inlet 18.

[0031] In an embodiment where the vibratory separator 20 is used to separate drilling fluid from drill cuttings, the drill cuttings may convey across the screen 25 to a discharge end of the vibratory separator 25 and at least a portion of the drilling fluid may be separated and move through apertures in the screen 25. The pressure differential generator 14 can draw additional drilling fluid through the screen 25. Increasing the amount of drilling fluid that passes through screen 25 before being discharged from the vibratory separator 20 may present several advantages. For example, by recovering more drilling fluid, the total amount of drilling fluid required for drilling may be reduced, as costly, recovered drilling fluid may be processed for reuse. As another example, increasing the amount of fluid passing through the screen 25 necessarily decreases the amount of drilling fluid remaining on the drill cuttings. This can decrease the mass of waste, further driving down costs, and may yield significant reductions in disposal costs.

[0032] When a liquid, such as drilling fluid, enters the mouth of the pressure differential generator 14, some of the liquid may be atomized into a fine mist. This atomization or misting of the liquid may make recapture of the liquid difficult. Additionally, liquid that is present in extremely fine droplets may more readily evaporate or otherwise be carried into the surrounding environment which may impact the amount of recoverable drilling fluid as well as necessary safety and environmental precautions.

[0033] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting.

Claims

1. A system, comprising:

a screen configured to separate drilling fluid from drill cuttings;

a tray positioned below the screen to collect a portion of the drilling fluid that passes through the screen;

a pressure differential generator positioned at least partially between the screen and the tray, the pressure differential generator having an interior passage in which pressurized fluid moves within to generate a pressure differential across the screen; a drain positioned to receive at least a portion of the drilling fluid moving through the screen, the drain having an interior connecting to the interior passage of pressure differential generator.

2. The system of claim 1 further comprising a vibratory separator having a frame supporting the screen, and a securement assembly for securing the tray to the frame of the vibratory separator.

3. The system of claim 2 wherein the securement assembly comprises a retention bar moving from a first position adjacent to the tray to a second position away from the tray, and further wherein at the second position the retention bar contacts the frame and applies a force against the frame to secure to the tray against the vibratory separator.

4. The system of claim 3 wherein the tray is force away from the frame and against a portion of the vibratory separator to prevent the tray from moving with respect to the vibratory separator.

5. The system of claim 1 wherein at least a portion of the pressure differential generator is positioned above the tray such that the portion is between the tray and the screen.

6. The system of claim 1, wherein at least a portion of pressure differential generator is positioned below the tray such that the tray is positioned between the portion and the screen.

7. The system of claim 1 further comprising an inlet to the pressure differential generator, the inlet positioned closer to the screen than a location where the interior of the drain and the interior of the passage of the pressure differential generator connect.

8. The system of claim 1 wherein the pressurized fluid moves through the interior passage of the pressure differential generator and pulls a portion of the drilling fluid through the screen that would not have moved through the screen without the pressure differential applied across the screen.

9. The system of claim 8 wherein the pressurized fluid moves through the interior passage of the pressure differential generator and toward the location where the interior of the drain and the interior of the passage of the pressure differential generator connect to fluid into and through the drain.

10. The system of claim 1 wherein the pressurized fluid moves through the pressure differential generator at a higher velocity at the inlet than at the location where the interior of the drain and the interior of the passage of the pressure differential generator connect.