WO2020180315A1

WO2020180315A1 - Coated shaker screen wire for use in oil and gas operations

Info

Publication number: WO2020180315A1
Application number: PCT/US2019/020954
Authority: WO
Inventors: Dale E. Jamison; William Walter SHUMWAY
Original assignee: Halliburton Energy Services, Inc.
Priority date: 2019-03-06
Filing date: 2019-03-06
Publication date: 2020-09-10
Also published as: WO2020180315A8

Abstract

Methods and systems for shaker screens having a hardened coating for use in shale shakers are provided. In some embodiments, shaker is provided that includes: a basket having one or more side walls and one or more ends; a screen assembly mounted in the basket, wherein the screen assembly includes a screen having a coating disposed on at least a portion of the surface of the screen; and a vibrator coupled to the basket.

Description

COATED SHAKER SCREEN WIRE FOR USE IN OIL AND GAS OPERATIONS

BACKGROUND

The present disclosure relates to methods and systems for shaker screens used in oil and gas operations.

When drilling a well (e.g., for oil or gas), a drill bit may be attached to the end of a drill string. The drill bit drills a hole through the subsurface to access the oil or gas reservoir. Drilling fluid is often used during drilling operations. Drilling fluid may comprise, for example, a finely ground clay base material to which various chemicals and water may be added to form a viscous fluid designed to meet specific physical properties appropriate for the subsurface conditions anticipated. This drilling fluid may be pumped down the hollow drill pipe, through the drill bit and returned to the surface in the annular space between the drill pipe and the well bore.

The drilling fluid may serve at least the following goals. First, it may aid in cooling and/or lubricating the drill bit, thereby increasing its useful life. Second, the drilling fluid may flush the cuttings or“solids” from the well bore and return them to the surface for processing by a solid control system. Third, the drilling fluid may leave a thin layer of the finely ground clay base material along the well bore walls which helps prevent caving in of the well bore wall. Although often referred to simply as“drilling mud” or“mud,” the drilling fluid may be a complex composition which must be carefully engineered and tailored to each individual well and drilling operation. The drilling fluid may be costly and, thus, may be cleaned and reused in a closed loop system that may include a solids control system that includes a shaker.

A screen separator may be part of a solids control system used in oil and gas operations to separate the solid material (“solids”) that become suspended in a drilling fluid during a drilling operation from the drilling fluid. These screen separators may be vibratory separators or shakers, often referred to as a“shale shaker.” For the drilling fluid to be used and reused, it may be processed after returning from the well bore to remove the solids and maintain its proper density, often expressed as pounds per gallon or“mud weight”, i.e., 10 lb./gal. mud or“10 lb. mud”. The first step in processing the returned drilling fluid may be to pass it through a shaker. The returned drilling fluid from the flow line may flow into a container mounted at one end of the shaker and then over one or more screens. A shaker may include a support frame on which the shaker screen is mounted. One or more motors in the shaker may cause the screen assemblies to vibrate or oscillate, depending on the type of motors utilized. The vibrating action of the screens over which the mud passes may remove larger particle size solids while allowing the drilling fluid and smaller particle size solids to pass through the screen. Solids, which may be discarded from the top of the shaker screen, may discharge into a pit or onto a conveyor for further treatment or disposal while the underflow drilling fluid flows into a tank below.

BRIEF DESCRIPTION OF THE DRAWINGS

These drawings illustrate certain aspects of some of the embodiments of the present disclosure and should not be used to limit or define the claims.

Figure 1 is a schematic representation of a side view of an example of a shale shaker that may be used in accordance with certain embodiments if the present disclosure.

Figure 2 is a schematic representation of a top view of an example of a shale shaker that may be used in accordance with certain embodiments if the present disclosure.

Figure 3 is a schematic representation of an end view of an example of a shale shaker that may be used in accordance with certain embodiments if the present disclosure.

Figure 4 is a schematic representation of a perspective view of an example of a shale shaker that may be used in accordance with certain embodiments if the present disclosure.

Figure 5 is a schematic representation of a side view of an example of a shale shaker that may be used in accordance with certain embodiments if the present disclosure.

Figure 6 is a schematic representation of a side view of an example of a screen separator that may be used in accordance with certain embodiments if the present disclosure.

Figure 7 is a schematic representation of a top view of an example of a screen mesh that may be used in accordance with certain embodiments if the present disclosure.

Figure 8 is a schematic representation of a cross-sectional view of an example of a screen mesh that may be used in accordance with certain embodiments if the present disclosure.

Figure 9 is a schematic representation of a perspective view of an example of a screen mesh that may be used in accordance with certain embodiments if the present disclosure.

While embodiments of this disclosure have been depicted, such embodiments do not imply a limitation on the disclosure, and no such limitation should be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.

DESCRIPTION OF CERTAIN EMBODIMENTS

The present disclosure relates to methods and systems for shaker screens used in oil and gas operations. More particularly, the present disclosure relates to shaker screens having a hardened coating for use in shale shakers.

A wide variety of screen separators may be used in various industries to separate components of material fed to the screen separator. Some screen separators may be vibratory separators or oscillatory separators, commonly referred to as“shale shakers” in the oil and gas industry. Other screen separators may be vacuum separators. In some embodiments of the present disclosure, the screen separators may combine features of both vibratory separators and vacuum separators. Often the material is a slurry which includes liquid and solids entrained therein. It may be desirable to separate some, the majority of, or all of the solids from the liquid. One or more screens may be mounted on a screen separator and the material to be treated may be introduced onto the screen(s). Liquid, and perhaps some smaller solids, may flow through the screen and may be collected while larger solids that do not flow through the screen move off the top of the screen. In other words, solids of one size may flow through the screen(s) and solids of another size may flow off the top of the screen.

Solids control may be needed for drilling fluid used in hydrocarbon well drilling. Drilling fluid may comprise, for example, a finely ground clay base material to which various chemicals and water are added to form a viscous fluid designed to have certain physical properties or meet certain specifications appropriate for the subsurface conditions anticipated. This drilling fluid may be pumped down a hollow drill pipe, through the drill bit and returned to the surface in the annular space between the drill pipe and the well bore. At the top of the well, the solids-laden fluid may be discharged over a shale shaker or other screen separator, a device which may comprise a series of screens arranged in tiered or flat disposition with respect to each other. The screens may catch and remove solids from the fluid as the fluid passes through them. If drilled solids are not removed from the fluid used during the drilling operation, in some cases, recirculation of the drilled solids may create weight, viscosity, and gel problems in the fluid, as well as increasing wear on mud pumps and other mechanical equipment used for drilling. In one or more embodiments of the present disclosure, the drilling fluid may then be recycled through the hollow drill pipe for reuse in the drilling operations.

In some shale shakers a fine screen mesh is used to create the screens for use in the shale shakers. In certain embodiments, the screens of the present disclosure may include a screen mesh that may be part of a screen assembly designed to give structural support to the screen mesh. In some embodiments, the screens of the present disclosure may be or comprise a single layer of screen mesh. In other embodiments, the screens of the present disclosure may have one or more overlying layers of screen mesh. In certain embodiments, these layers may be bonded together. In one or more embodiments, these screen mesh layers may be installed on top of one or more supports or a perforated or apertured plate to provide structural stability. In certain embodiments, the frame of the screen may be suspended or mounted upon a support or basket. In some embodiments, the screen, or the corresponding support or basket, may be coupled to a separation enhancer. A person of skill in the art would understand that separation enhancers may aid in the separation of the drilling fluids and solids that are fed to the screen. For example, in some embodiments, separation enhancers may cause the drilling fluid to pass through the screen at a higher rate. In other embodiments, separation enhancers may cause the solids to exit the screen at a higher rate. In still other embodiments, separation enhancers may aid in the separation of the drilling fluids and solids using a combination of the these, and other, mechanisms. In some embodiments, the separation enhancer may cause the screen to vibrate using a vibrator coupled to the screen, or the corresponding support or basket, e.g. an unbalanced weight on a rotating shaft, connected to the frame. Each screen may be vibrated by one or more vibrators or other vibrating mechanisms to create a flow of trapped solids on top surfaces of the screen for removal and disposal of solids. In other embodiments, the separation enhancer may be a vacuum or vacuum pump fluidically coupled to the screen. The vacuum may create a pressure differential across the screen to“pull” the drilling fluid through the screen at a higher rate.

In one or more embodiments of the present disclosure, the screens may be formed as a woven mesh of wires in both the wrap and the weft directions of a plurality of wires. In some embodiments, the wrap and weft wires may comprise a generally circular, or cylindrical, shape. In other embodiments, the wrap and weft wires may comprise an elliptical, or oval, shape having a cross section whose height is greater than its width and exhibiting a rounded upper and lower surface. In still other embodiments, the wrap and weft wires may comprise a generally flat shape. A person of skill in the art would understand that the shape and size of the wrap and weft may be selected based on the needs of a particular shaker screen operation. In some embodiments, the wrap and weft wires may share the same, or substantially similar, shape and size. In other embodiments, the wrap and weft wires may have different shapes and/or sizes. The spacing of the wrap and weft wires, at least in part determines the size of mesh opening. The fineness or coarseness of the mesh of a screen may vary depending upon fluid flow rate and the size of the solids to be removed. In some embodiments, the size of mesh opening may correspond to an API Screen standard size. In some embodiments, the screen mesh may comprise a screen with openings having a size in the range of API 20 TO API 400. In other embodiments, the screen mesh may comprise a screen with openings having a size in the range of API 40 to API 325. In still other embodiments, the screen mesh may comprise a screen with openings having a size in the range of API 70 to API 270. Table 1 below shows the mesh separation sizes of common API Screen Numbers that may be suitable for the screens of the present disclosure.

Table 1. API Screen Sizes

API Screen No. D100 Separation (Microns)

API 20 780.0-925.0

API 25 655.0-780.0

API 30 550.0-655.0

API 35 462.5 - 550.0

API 40 390.0-462.5

API 45 327.5-390.0

API 50 275.0-327.5

API 60 231.0-275.0

API 70 196.0-231.0

API 80 165.0-196.0

API 100 137.5- 165.0 API 120 116.5-137.5 API 140 98.0-116.5 API 170 82.5-98.0 API 200 69.0 - 82.5 API 230 58.0-69.0 API 270 49.0-58.0 API 325 41.5-49.0 API 400 35.0-41.5

In certain embodiments, the screens of the present disclosure may have a mesh opening that is generally square in shape. However, in other embodiments, mesh openings may be rectangular in form. In one or more embodiments, the wrap wires and the weft wires may be identical in cross section and are crimped identically to form a series of upwardly projecting knuckles and downwardly facing knuckles. In some embodiments, only the wrap or weft wires may be crimped to form the upwardly projecting knuckles and downwardly facing knuckles while the other wires may be substantially straight without upper or lower knuckles. In other embodiments, both the wrap and weft wires may be crimped to form the upwardly projecting knuckles and downwardly facing knuckles. In some embodiments, the knuckles of the weft wires may be nested with the corresponding knuckles of the wrap wires.

In certain embodiments, the screens of the present disclosure may comprise a dirty side and a clean side. In some embodiments, dirty side may be exposed to a fluid comprising a higher percentage of solids for separation by the screen than the fluid exposed or passed to the clean side. The fluid may pass through screen from dirty side to clean side, leaving behind solid particles that are too large to pass through the mesh openings in the screen. In one or more embodiments, a coating may be applied to one or more sides of screen. In some embodiments, the coating may be applied to the entirety of the wires before assembly of the screen. In other embodiments, the coating may be applied to one or more sides of the screen after assembly. In some embodiments, the coating may be applied only to the dirty side of the screen. A person of skill in the art would understand that the dirty side of the screen may receive more contact with solid particulate than the clean side, and therefore would be most likely to benefit from a coating. In other embodiments, the coating may be applied to both the dirty side and the clean side of the screen.

In accordance with one or more embodiments of the present disclosure, the screen meshes may be manufactured from any material suitable in typical oil and gas drilling operations. In some embodiments, the screen meshes may be manufactured out of materials including, but not necessarily limited to, copper, nickel, chromium, iron, titanium, alloys thereof, or any combination comprising at least one of the foregoing. In other embodiments, the screen meshes may be manufactured out of steel, nickel-chromium based alloys such as INCONEL® alloys, commercially available from Special Metals Corporation, headquartered in New Hartford, NY 13413, or nickel-copper based alloys such as MONEL® alloys, commercially available from Special Metals Corporation in New Hartford, NY. The steel can be a stainless steel containing about 10% to about 20% of chromium. The stainless steel can also contain about 8% to about 18% of nickel. Nickel-chromium based alloys may contain about 40-75% of nickel and about 10-35% of chromium. The nickel-chromium based alloys can also contain about 1 to about 15% of iron. Small amounts of molybdenum, niobium, cobalt, manganese, copper, aluminum, titanium, silicon, carbon, sulfur, phosphorus, boron, or a combination comprising at least two of the foregoing can also be included in the nickel-chromium based alloys. Nickel-copper based alloys may be primarily composed of nickel (up to about 67%) and copper. The nickel-copper based alloys may also contain small amounts of iron, manganese, carbon, and silicon. As used herein, the term “metal-based alloy” means a metal alloy wherein the weight percentage of the specified metal in the alloy is greater than the weight percentage of any other component of the alloy, based on the total weight of the alloy. In some embodiments, the screen may be manufactured from carbon composite materials. In other embodiments, the screen may be manufactured from one or more polymers, including, but not limited to, epoxies, aramids, polyethylene terephthalate, Spectra™, commercially available from Honeywell International Inc. in Charlotte, NC, and Micro Dyneema™, commercially available from DSM Dyneema, B.Y. in Greenville, NC. In still other embodiments, the screens may be manufactured from natural fibers, including, but not limited to, silk and hemp.

In accordance with one or more embodiments of the present disclosure, a coating may be disposed on at least a portion of a surface of the screen mesh. In certain embodiments, the coating is designed to protect the screen mesh, thereby allowing the screen mesh to maintain its integrity and functionality for longer periods of time or during exposure to more abrasive materials as compared to an uncoated screen mesh. Additionally, in some embodiments, the coating may increase the performance of the screen mesh as compared to an uncoated screen mesh. Without intending to be limited to any particular theory or mechanism, it is believed that performance may be improved by allowing the screen mesh to de-water more efficiently (i.e., the screen may allow liquid to pass through the openings in the screen mesh quicker). In some embodiments, the coating may be applied to the screen mesh after the screen has been assembled. In other embodiments, the coating may be applied to the wires before the screen mesh is formed. In some embodiments, similar methods of applying the coating to the wires may be used regardless of whether the coating is applied to the wires before or after the screen mesh is formed.

In one or more embodiments, the coatings may impart an increased hardness to the screen mesh. For example, in some embodiments, the coating may have a hardness of greater than about 9 on a Mohs hardness scale. In other embodiments, the coating may have a hardness of greater than or equal to about 10 on a Mohs hardness scale.

The coating may be comprised of any suitable material in the art. In certain embodiments, the coating may be selected from the group consisting of composite diamond, electroless nickel with boron nitride, electroless nickel coating such as those commercially available from Endura® Coatings in Sterling Heights, MI, ceramics, and hardened chromium plating. In one or more embodiments, the coating may include an amorphous diamond-like carbon doped with about 10 to about 30 atomic percent of silicon, about 10 to about 20 atomic percent of oxygen, or a combination comprising at least two of the foregoing dopants. In some embodiments, the amorphous diamond-like carbon may further comprise 15 to 25 atomic percent of hydrogen atoms. Dopants such as fluorine and hydrogen may also be included. In certain embodiments, the amorphous diamond-like carbon may comprise 60 to 90 atomic percent of sp2 bonded carbon and 10 to 40 atomic percent of sp3 bonded carbon. As used herein,“sp2 bonded carbon” refers to carbon atoms bonded to neighboring carbon atoms in a crystal structure substantially corresponding to the graphite isotope of carbon.“Sp3 bonded carbon” refers to carbon atoms bonded to neighboring carbon atoms in a crystal structure substantially corresponding to the diamond isotope of carbon. In certain embodiments, the dopants may be uniformly distributed in the coating. Alternatively, in other embodiments, the dopants may be present in a gradient. For example, in some embodiments, an atomic concentration of silicon, oxygen, fluorine, or a combination comprising at least two of the foregoing in the coating may decrease in a direction towards the surface of the screen mesh. In other embodiments, an atomic concentration of silicon, oxygen, fluorine, or a combination comprising at least two of the foregoing in the coating may decrease in a direction towards the outer surface of the coating. In one or more embodiments, depending on the composition of the screen mesh, a layer of silicon, chromium, titanium, zirconium or their alloys may be used between the screen mesh and the doped diamond-like carbon coating to facilitate better adhesion between the mesh and the coating.

In certain embodiments, the coating may be deposited on a surface of the screen mesh by vapor deposition. A“vapor deposition” process refers to a process of depositing materials on a substrate through the vapor phase. Vapor deposition processes include physical vapor deposition, chemical vapor deposition, and plasma-assisted vapor deposition. Different variations of physical deposition, chemical deposition, and plasma-assisted vapor deposition can be used. In some embodiments, the deposition processes can include plasma assisted chemical vapor deposition, sputtering, ion beam deposition, laser ablation, or thermal evaporation. In one or more embodiments, the coating may be deposited by plasma ion immersion implantation and deposition. In certain embodiments, the thickness of the coating may vary depending on the gauge of the screen (opening gap between the screen and the base pipe) as well as the materials used for the coating. When the coating comprises the doped amorphous diamond-like carbon, it may have a thickness of about 0.5 microns to about 5 microns or about 0.5 to about 3 microns.

FIGS. 1 to 3 illustrate a shale shaker 10 that may be used in accordance with certain embodiments of the shaker screens of the present disclosure. In one or more embodiments of the present disclosure, shale shaker 10 may be positioned or located at a surface location proximate to a well bore. A drilling fluid may be stored in a mud pit or other suitable vessel at the well bore and pumped down a hollow drill pipe, through the drill bit and returned to the surface in the annular space between the drill pipe and the well bore. At the top of the well, the solids-laden drilling fluid may be discharged over the shale shaker to remove the solids from the drilling fluid. The drilling fluid may then be re-circulated into the mud pit and/or well bore using the hollow drill pipe. The solids may be collected from shale shaker 10 for storage and/or disposal.

Shale shaker 10 may have a screen-mounting basket 12 and a bridge 14 on which one or more separation enhancers 20 may be mounted. Basket 12 may comprise a generally rectangular box having side walls 12a, 12b and ends 12c, 12d. A person of skill in the art would understand that separation enhancers 20 may aid in the separation of the drilling fluids and solids that are fed to the screen. For example, in some embodiments, separation enhancers 20 may cause the drilling fluid to pass through the screen at a higher rate. In other embodiments, separation enhancers 20 may cause the solids to exit the screen at a higher rate. In still other embodiments, separation enhancers 20 may aid in the separation of the drilling fluids and solids using a combination of the these, and other, mechanisms. As depicted in FIGS. 1 to 3, separation enhancers 20 are shown as vibrators. The basket 12 may have bracket 16 to which helical springs 18 may be secured. Each spring 18 may be secured to a base member 22. As shown in FIG. 3, in certain embodiments housing 24 may be used on sides of and beneath the shale shaker 10. One or more sensors 29 may be coupled to housing 24, but may, in accordance with the present disclosure, be within any suitable member or part of a shale shaker; and, optionally, such sensors 29 may have a container or housing that may be made of composite material and/or may be encased within or coated with composite material. A person of ordinary skill in the art would understand that any number of sensors may suitable for use in monitoring and tracking the operations of shale shaker 10 may be used. For example, in some embodiments, sensor 29 may be used to measure the degree or amount of vibrations of shale shaker 10. In other embodiments, sensor 29 may be used to measure the rate of fluid flow through shale shaker 10. In still other embodiments, sensor 29 may be used to measure the rate of solids collection of shale shaker 10.

In some embodiments, the brackets 16, base members 22, and housing 24 may be manufactured using any suitable material, including one or more composite materials. In other embodiments, the brackets 16, base members 22, and housing 24 may be manufactured using iron, steel, stainless steel, alloys, or any other material that has sufficient strength and mechanical properties. In some embodiments, the basket 12, including side walls 12a, 12b and ends 12c, 12d, may also be manufactured using one or more composite materials. In other embodiments, the basket 12, including side walls 12a, 12b and ends 12c, 12d, may also be manufactured using iron, steel, stainless steel, alloys, or any other material that has sufficient strength and mechanical properties. In still other embodiments, one, some, or all of these components may be made of steel encased in composite materials or steel coated with composite materials. A coating of composite materials on any of these components may have the thickness of, for example, a layer of paint or of two, three, four or more layers of paint.

FIG. 4 shows a shale shaker 30 that may be used in accordance with certain embodiments of the shaker screens of the present disclosure, which has screen 33 mounted in a basket 32 Although the embodiment of the shale shaker 30 depicted in FIG. 3 is shown with a single screen 33, a person of skill in the art would understand that in certain embodiments, any number of screens may be used. In one or more embodiments, springs 34 may be mounted between basket mount members 37 and mount members 35 on a frame 36. In some embodiments, springs 34 may be used for isolating vibration of the shale shaker 30 from frame 36. In certain embodiments, vibrator 38 may be coupled to basket 32 and may vibrate the basket 32 to vibrate the screen 33. In some embodiments, elevator apparatus 31 provides for raising and lowering of the basket end 40. In one or more embodiments, posts 39 may be secured to the basket 32 and may extend through corresponding holes in the mount members 37. In accordance with certain embodiments of the present disclosure, the basket 32, mount members 35, frame 36, mount members 37, and posts 39 may be manufactured using one or more composite materials. In other embodiments, the basket 32, mount members 35, frame 36, mount members 37, and posts 39 may be manufactured using iron, steel, stainless steel, alloys, or any other material that has sufficient strength and mechanical properties.

FIG. 5 shows a shale shaker 40 that may be used in accordance with certain embodiments of the shaker screens of the present disclosure, which has a lower base frame 41. In certain embodiments, screen bed support frame 42 may be mounted on lower base frame 41. In one or more embodiments, mount members 45a may be connected to the support frame 42 and mount members 45b may be connected to the base frame 41. In some embodiments, air springs 44 may be positioned between mount members 45a and mount members 45b. Mount members 45a and mount members 45b may provide resilient support for the support frame 42. In certain embodiments, vibrator 47 may be connected to the support frame 42. Vibrator 47 may vibrate the support frame 42 and therefore vibrate one or more screens mounted on the support frame 42. In one or more embodiments, a vertical strut 45 may provide support for the vibrator 47. In some embodiments, each air spring 44 may comprise a body 44a. The support frame 42 may have sufficient height or depth to form a basket around the edges of the screen to inhibit larger particles falling off the sides or end of the screens and to guide the larger particles into a conveyor ditch, skip or hopper for further processing and to guide contain liquid before it passes through the screen. In certain embodiments, the base frame 41, bodies 44a, strut 45, mount members 45a, and/or mount members 45b may be manufactured using one or more composite materials or of steel encased in or coated with composite material. In other embodiments, the base frame 41, bodies 44a, strut 45, mount members 45a, and/or mount members 45b may be manufactured using iron, steel, stainless steel, alloys, or any other material that has sufficient strength and mechanical properties

FIG. 6 shows a shale shaker 60 that may be used in accordance with certain embodiments of the shaker screens of the present disclosure which has a stationary base 61. In one or more embodiments, stationary base 61 may be coupled to a moving frame 62. In some embodiments, moving frame 62 may be moved by apparatus 64 connected to the moving frame 62. In one or more embodiments, intervening resilient members 63 may be positioned between brackets 69 of the moving frame 62 and posts 67 of the stationary base 61. Screens 65 and 66 may be mounted on corresponding decks 65a and 66a, respectively. Although the embodiment of the shale shaker 60 depicted in FIG. 6 is shown with two screens 65 and 66, a person of skill in the art would understand that in certain embodiments, any number of screens may be used. It is also to be understood that although only one side of the separator 60 is shown in FIG. 6, the other side has a structure substantially similar to the side that is shown (as is true for the apparatus of FIGS. 4 and 5 also). In accordance with the present invention, the base 61, resilient members 63, brackets 69, posts 67, and/or decks 65a, 66a may be manufactured using one or more composite materials or steel encased in or coated with composite material. In other embodiments, the base 61, resilient members 63, brackets 69, posts 67, and/or decks 65a, 66a may be manufactured using iron, steel, stainless steel, alloys, or any other material that has sufficient strength and mechanical properties.

FIG. 7 shows a depiction of a screen 70 in accordance with one or more embodiments of the present disclosure. Screen 70 may be formed as a woven mesh of wires in both the wrap and the weft directions of wires 71 and 72. In FIG. 7, the wrap wires are designated by the reference characters 71 and the weft wires are designated by the reference characters 72. In some embodiments, wires 71 and 72 may comprise a generally circular, or cylindrical, shape. In other embodiments, wires 71 and 72 may comprise an elliptical, or oval, shape having a cross section whose height is greater than its width and exhibiting a rounded upper and lower surface. In still other embodiments, wires 71 and 72 may comprise a generally flat shape. A person of skill in the art would understand that the shape of wires 71 and 72 may be selected based on the needs of a particular shaker screen operation. The spacing of wires 71 and 72, at least in part determines the size of mesh opening 73.

As shown in FIG. 7, one or more embodiments of the present disclosure may have a mesh opening 73 that is generally square in shape. However, in other embodiments, mesh openings may be rectangular in form. In the screen 70 depicted in FIG. 7, the wrap wires 71 and the weft wires 72 are identical in cross section and are crimped identically as shown in FIG. 8 as wrap wires 81a, 81b and weft wires 82 to form a series of upwardly projecting knuckles 83 and downwardly facing knuckles 84. In FIG. 8, the knuckles 83 and 84 are shown in the wrap wires 81a, 81b, but it is apparent that in some embodiments, the weft wires 82 may comprise corresponding knuckles, the upper knuckles of the weft wires being nested with the lower knuckles 84 of the wrap wires 81a, 81b and the lower knuckles of the weft wires nested with the upper knuckles 83 of the wrap wires 81 a, 81 b. In other embodiments, weft wires 82 may be substantially straight without upper or lower knuckles.

FIG. 9 depicts a side-angle view of a screen 90 in accordance with one or more embodiments of the present disclosure. Screen 90 may comprise dirty side 91 and clean side 92. In some embodiments, dirty side 91 may be exposed to a fluid comprising a higher percentage of solids for separation by screen 90 than the fluid exposed or passed to the clean side 92. The fluid may pass through screen 90 from dirty side 91 to clean side 92, leaving behind solid particles 93 that are too large to pass through the mesh openings 94 in screen 90. In one or more embodiments, a coating 95 may be applied to one or more sides of screen 90. In some embodiments, coating 95 may be applied to the entirety of the wires before assembly of screen 90. In other embodiments, coating 95 may be applied to one or more sides of screen 90 after assembly. In some embodiments, coating 95 may be applied only to dirty side 91 of screen 90. A person of skill in the art would understand that dirty side 91 of screen 90 may receive the most contact with solid particulate, and therefore would be most likely to benefit from coating 95. In other embodiments, coating 95 may be applied to both dirty side 91 and clean side 92 of screen 90.

An embodiment of the present disclosure is a basket having one or more side walls and one or more ends; a screen assembly mounted in the basket, wherein the screen assembly includes a screen having a coating disposed on at least a portion of the surface of the screen; and a vibrator coupled to the basket.

In one or more embodiments described in the preceding paragraph, the coating is selected from the group consisting of a composite diamond coating, an electroless nickel with boron nitride coating, an electroless nickel coating, a ceramic coating, a hardened chromium plating, and any combination thereof. In one or more embodiments described above, the coating is a composite diamond coating. In one or more embodiments described above, the composite diamond coating is applied using a vapor deposition technique. In one or more embodiments described above, the coating includes a hardness rating of greater than about 9 on a Mohs scale. In one or more embodiments described above, the screen includes a dirty side and a clean side. In one or more embodiments described above, the coating is disposed on at least a portion of the dirty side and at least a portion of the clean side. In one or more embodiments described above, the coating is disposed on at least a portion of the dirty side and is not disposed on at least a portion of the clean side. In one or more embodiments described above, the screen includes a woven mesh of wires comprising one or more wrap wires and one or more weft wires. In one or more embodiments described above, the screen includes an opening gage of less than about 925 microns.

Another embodiment of the present disclosure is a screen including a woven mesh of one or more wrap wires and one or more weft wires, wherein the woven mesh further includes one or more upper knuckles and one or more lower knuckles; and a coating disposed on the one or more wrap wires and the one or more weft wires.

In one or more embodiments described in the preceding paragraph, the screen further includes a dirty side and a clean side. In one or more embodiments described above, the coating is disposed on at least a portion of the dirty side and at least a portion of the clean side. In one or more embodiments described above, the coating is disposed on at least a portion of the dirty side and is not disposed on at least a portion of the clean side. In one or more embodiments described above, the coating is selected from the group consisting of a composite diamond coating, an electroless nickel with boron nitride coating, an electroless nickel coating, a ceramic coating, a hardened chromium plating, and any combination thereof. In one or more embodiments described above, the coating includes a hardness rating of greater than about 9 on a Mohs scale.

Another embodiment of the present disclosure is a method that includes: providing a separator including: a basket; a screen assembly mounted in the basket, wherein the screen assembly includes a screen having a coating disposed on at least a portion of the surface of the screen; and a separation enhancer coupled to the basket; passing a drilling fluid through the screen; and removing one or more solid particulates from the drilling fluid using the screen assembly.

In one or more embodiments described in the preceding paragraph, the separation enhancer comprises a vibrator, a vacuum, or both. In one or more embodiments described above, the method further includes drilling at least a portion of a well bore penetrating a subterranean formation using the drilling fluid. In one or more embodiments described above, the method further includes recycling the drilling fluid by using the drilling fluid to drill at least a second portion of the well bore after passing the drilling fluid through the screen.

Therefore, the present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. While numerous changes may be made by those skilled in the art, such changes are encompassed within the spirit of the subject matter defined by the appended claims. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present disclosure. In particular, every range of values ( e.g .,“from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently,“from approximately a-b”) disclosed herein is to be understood as referring to the power set (the set of all subsets) of the respective range of values. The terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.

Claims

What is claimed is:

1. A shaker comprising:

a basket having one or more side walls and one or more ends;

a screen assembly mounted in the basket, wherein the screen assembly comprises a screen having a coating disposed on at least a portion of the surface of the screen; and

a vibrator coupled to the basket.

2. The shaker of claim 1, wherein the coating is selected from the group consisting of a composite diamond coating, an electroless nickel with boron nitride coating, an electroless nickel coating, a ceramic coating, a hardened chromium plating, and any combination thereof.

3. The shaker of claim 1, wherein the coating is a composite diamond coating.

4. The shaker of claim 3, wherein the composite diamond coating is applied using a vapor deposition technique.

5. The shaker of claim 1, wherein the coating comprises a hardness rating of greater than about 9 on a Mohs scale.

6. The shaker of claim 1, wherein the screen comprises a dirty side and a clean side.

7. The shaker of claim 6, wherein the coating is disposed on at least a portion of the dirty side and at least a portion of the clean side.

8. The shaker of claim 6, wherein the coating is disposed on at least a portion of the dirty side and is not disposed on at least a portion of the clean side.

9. The shaker of claim 1, wherein the screen comprises a woven mesh of wires comprising one or more wrap wires and one or more weft wires.

10. The shaker of claim 1, wherein the screen comprises an opening gage of less than about 925 microns.

1 1. A screen comprising:

a woven mesh of one or more wrap wires and one or more weft wires, wherein the woven mesh further comprises one or more upper knuckles and one or more lower knuckles; and

a coating disposed on the one or more wrap wires and the one or more weft wires.

12. The screen of claim 11 further comprising a dirty side and a clean side.

13. The screen of claim 12, wherein the coating is disposed on at least a portion of the dirty side and at least a portion of the clean side.

14. The screen of claim 12, wherein the coating is disposed on at least a portion of the dirty side and is not disposed on at least a portion of the clean side.

15. The screen of claim 11, wherein the coating is selected from the group consisting of a composite diamond coating, an electroless nickel with boron nitride coating, an electroless nickel coating, a ceramic coating, a hardened chromium plating, and any combination thereof.

16. The screen of claim 1, wherein the coating comprises a hardness rating of greater than about 9 on a Mohs scale.

17. A method comprising:

providing a separator comprising:

a basket;

a screen assembly mounted in the basket, wherein the screen assembly comprises a screen having a coating disposed on at least a portion of the surface of the screen; and a separation enhancer coupled to the basket;

passing a drilling fluid through the screen; and

removing one or more solid particulates from the drilling fluid using the screen assembly.

18. The method of claim 17, wherein the separation enhancer comprises a vibrator, a vacuum, or both.

19. The method of claim 17 further comprising drilling at least a portion of a well bore penetrating a subterranean formation using the drilling fluid.

20. The method of claim 19 further comprising recycling the drilling fluid by using the drilling fluid to drill at least a second portion of the well bore after passing the drilling fluid through the screen.