Patent Publication Number: US-7909172-B2

Title: Composite screen with integral inflatable seal

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application, pursuant to 35 U.S.C. §119(e), claims priority to U.S. Provisional Application Ser. No. 60/827,598, filed Sep. 29, 2006. That application is incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     The invention relates generally to oilfield shale shakers. More particularly, embodiments disclosed herein relate to seals for screen frames for oilfield shale shakers. 
     2. Background Art 
     Oilfield drilling fluid, often called “mud,” serves multiple purposes in the industry. Among its many functions, the drilling mud acts as a lubricant to cool rotary drill bits and facilitate faster cutting rates. Typically, the mud is mixed at the surface and pumped downhole at high pressure to the drill bit through a bore of the drillstring. Once the mud reaches the drill bit, it exits through various nozzles and ports where it lubricates and cools the drill bit. After exiting through the nozzles, the “spent” fluid returns to the surface through an annulus formed between the drillstring and the drilled wellbore. 
     Furthermore, drilling mud provides a column of hydrostatic pressure, or head, to prevent “blow out” of the well being drilled. This hydrostatic pressure offsets formation pressures thereby preventing fluids from blowing out if pressurized deposits in the formation are breeched. Two factors contributing to the hydrostatic pressure of the drilling mud column are the height (or depth) of the column (i.e., the vertical distance from the surface to the bottom of the wellbore) itself and the density (or its inverse, specific gravity) of the fluid used. Depending on the type and construction of the formation to be drilled, various weighting and lubrication agents are mixed into the drilling mud to obtain the right mixture. Typically, drilling mud weight is reported in “pounds,” short for pounds per gallon. Generally, increasing the amount of weighting agent solute dissolved in the mud base will create a heavier drilling mud. Drilling mud that is too light may not protect the formation from blow outs, and drilling mud that is too heavy may over invade the formation. Therefore, much time and consideration is spent to ensure the mud mixture is optimal. Because the mud evaluation and mixture process is time consuming and expensive, drillers and service companies prefer to reclaim the returned drilling mud and recycle it for continued use. 
     Another significant purpose of the drilling mud is to carry the cuttings away from the drill bit at the bottom of the borehole to the surface. As a drill bit pulverizes or scrapes the rock formation at the bottom of the borehole, small pieces of solid material are left behind. The drilling fluid exiting the nozzles at the bit acts to stir-up and carry the solid particles of rock and formation to the surface within the annulus between the drillstring and the borehole. Therefore, the fluid exiting the borehole from the annulus is a slurry of formation cuttings in drilling mud. Before the mud can be recycled and re-pumped down through nozzles of the drill bit, the cutting particulates must be removed. 
     Apparatus in use today to remove cuttings and other solid particulates from drilling fluid are commonly referred to in the industry as “shale shakers.” A shale shaker, also known as a vibratory separator, is a vibrating sieve-like table upon which returning solids laden drilling fluid is deposited and through which clean drilling fluid emerges. Typically, the shale shaker is an angled table with a generally perforated filter screen bottom. Returning drilling fluid is deposited at the feed end of the shale shaker. As the drilling fluid travels down length of the vibrating table, the fluid falls through the perforations to a reservoir below leaving the solid particulate material behind. The vibrating action of the shale shaker table conveys solid particles left behind until they fall off the discharge end of the shaker table. The above described apparatus is illustrative of one type of shale shaker known to those of ordinary skill in the art. In alternate shale shakers, the top edge of the shaker may be relatively closer to the ground than the lower end. In such shale shakers, the angle of inclination may require the movement of particulates in a generally upward direction. In still other shale shakers, the table may not be angled, thus the vibrating action of the shaker alone may enable particle/fluid separation. Regardless, table inclination and/or design variations of existing shale shakers should not be considered a limitation of the present disclosure. 
     Preferably, the amount of vibration and the angle of inclination of the shale shaker table are adjustable to accommodate various drilling fluid flow rates and particulate percentages in the drilling fluid. After the fluid passes through the perforated bottom of the shale shaker, it can either return to service in the borehole immediately, be stored for measurement and evaluation, or pass through an additional piece of equipment (e.g., a drying shaker, centrifuge, or a smaller sized shale shaker) to further remove smaller cuttings. 
     Because shale shakers are typically in continuous use, any repair operations and associated downtimes are to be minimized as much as possible. Often, the filter screens of shale shakers, through which the solids are separated from the drilling mud, wear out over time and need replacement. Therefore, shale shaker filter screens are typically constructed to be quickly and easily removed and replaced. Generally, through the loosening of only a few bolts, the filter screen can be lifted out of the shaker assembly and replaced within a matter of minutes. While there are numerous styles and sizes of filter screens, they generally follow similar design. Typically, filter screens include a perforated plate base upon which a wire mesh, or other perforated filter overlay, is positioned. The perforated plate base generally provides structural support and allows the passage of fluids therethrough, while the wire mesh overlay defines the largest solid particle capable of passing therethrough. While many perforated plate bases are generally flat or slightly curved in shape, it should be understood that perforated plate bases having a plurality of corrugated channels extending thereacross may be used instead. In theory, the corrugated channels provide additional surface area for the fluid-solid separation process to take place, and act to guide solids along their length toward the end of the shale shaker from where they are disposed. 
     A typical shale shaker filter screen includes a plurality of hold-down apertures at opposite ends of the filter screen. These apertures, preferably located at the ends of the filter screen that will abut walls of the shale shaker, allow hold down retainers of the shale shaker to grip and secure the filter screens in place. However, because of their proximity to the working surface of the filter screen, the hold-down apertures must be covered to prevent solids in the returning drilling fluid from bypassing the filter mesh through the hold-down apertures. To prevent such bypass, an end cap assembly is placed over each end of the filter screen to cover the hold-down apertures. Presently, these caps are constructed by extending a metal cover over the hold down apertures and attaching a wiper seal thereto to contact an adjacent wall of the shale shaker. Furthermore, epoxy plugs are set in each end of the end cap to prevent fluids from communicating with the hold-down apertures through the sides of the end cap. 
     Typically, screens used with shale shakers are emplaced in a generally horizontal fashion on a generally horizontal bed or support within a basket in the shaker. The screens themselves may be flat or nearly flat, corrugated, depressed, or contain raised surfaces. The basket in which the screens are mounted may be inclined towards a discharge end of the shale shaker. The shale shaker imparts a rapidly reciprocating motion to the basket and hence the screens. Material from which particles are to be separated is poured onto a back end of the vibrating screen. The material generally flows toward the discharge end of the basket. Large particles that are unable to move through the screen remain on top of the screen and move toward the discharge end of the basket where they are collected. The smaller particles and fluid flow through the screen and collect in a bed, receptacle, or pan beneath the screen. 
     In some shale shakers a fine screen cloth is used with the vibrating screen. The screen may have two or more overlying layers of screen cloth or mesh. Layers of cloth or mesh may be bonded together and placed over a support, supports, or a perforated or apertured plate. The frame of the vibrating screen is resiliently suspended or mounted upon a support and is caused to vibrate by a vibrating mechanism (e.g., an unbalanced weight on a rotating shaft connected to the frame). Each screen may be vibrated by vibratory equipment to create a flow of trapped solids on top surfaces of the screen for removal and disposal of solids. The fineness or coarseness of the mesh of a screen may vary depending upon mud flow rate and the size of the solids to be removed. 
     Currently, in many shale shakers, the seal between the screen and the shaker basket is formed by a gasket disposed along the inner perimeter of the shaker basket. In addition to the gasket, a steel rigid support member is often affixed along longitudinal and lateral support members disposed on a bottom or inner surface of the shaker basket upon which the steel frame of the shaker screen rests. The weight of the screen and the disposition of a wedge member between the shaker basket and the screen compresses the gasket between the shaker basket and the frame of the screen. In such an assembly, the compression of the gasket is limited by the thickness of the steel rigid support member. Thus, a relatively thin steel rigid support member will result in greater gasket compression and less space between the screen and the shaker basket. Correspondingly, a relatively thick steel rigid support member will result in less gasket compression and more space between the screen and the shaker basket. 
     In shale shakers using a steel rigid support member to define the compression between the gasket and the shaker basket, an overly compressed gasket may cause the wedge to loosen and the screen to become loose. When a gasket is overly compressed, the vibrations of the shale shaker may cause the screen to move vertically relative to the shale shaker. When such vertical screen movement occurs, drilling fluid and/or cuttings may pass between the screen and the shaker basket, therein bypassing the screen. The bypassing of such drilling fluid and/or cuttings may decrease the efficiency of the shaking process, as well as allowing cutting matter to settle between the gasket and the shaker basket, thereby resulting in the loss of additional drilling fluid. 
     When drill cuttings and/or fluid is allowed constant contact with the sealing element of a shale shaker, the sealing element may wear out relatively quickly. In such systems wherein the sealing element is disposed and/or attached to the inner diameter of the shaker basket, replacing the sealing element can be a time consuming process that requires shutting down the shaker system, thus decreasing the efficiency of the process. 
     Accordingly, there exists a need for a screen frame assembly that may be securely positioned within a shale shaker while effectively reducing the amount of cutting particulates that may bypass the screen. Further, there exists a need for forming a seal against a wall of the shaker and neighboring screens, thereby minimizing the passage of unfiltered drilling mud therethrough. 
     SUMMARY OF INVENTION 
     In one aspect, embodiments disclosed herein relate to a shaker screen including a screen frame and an inflatable sealing element integrally formed with the screen frame. 
     In another aspect, embodiments disclosed herein relate to a screen sealing system including a plurality of shaker screens, each shaker screen having a screen frame and an inflatable sealing element integrally formed with the screen frame, wherein the inflatable sealing elements of each shaker screen are in fluid communication. 
     In another aspect, embodiments disclosed herein relate to a method of sealing a composite screen including assembling at least one shaker screen within a shale shaker and inflating at least one inflatable sealing element disposed along at least a portion of a perimeter of the screen frame, the portions selected from a group consisting of a top surface, a bottom surface, and an outer surface. 
     Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is perspective view of a vibratory shaker in accordance with embodiments disclosed herein. 
         FIGS. 2A-2C  show partial cross-sectional views of shaker screens in accordance with embodiments disclosed herein. 
         FIGS. 3A-3C  show partial side views of shaker screens in accordance with embodiments disclosed herein. 
         FIGS. 4A-4B  show perspective views of shaker screens in accordance with embodiments disclosed herein. 
         FIG. 5  shows a perspective view of shaker screens in accordance with embodiments disclosed herein. 
         FIG. 6  shows a perspective view of a shaker screen in accordance with embodiments disclosed herein. 
         FIG. 7  shows a perspective view of a fitting in accordance with embodiments disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     Generally, embodiments disclosed herein relate to apparatuses and methods for efficiently sealing shaker screens. More specifically, embodiments disclosed herein relate to shaker screens for inflatably sealing screen frames. Additionally, embodiments disclosed herein relate to inflatable screen sealing systems for shale shakers. 
     Referring to  FIG. 1 , a vibratory shaker  100  is shown. As shown, a screen  102  is detachably secured to vibratory shaker  100 . With the screen or a plurality of screens secured in place, a tray is formed with the opposed, parallel sidewalls  103  of shaker  100 . Drilling mud, along with drill cuttings and debris, is deposited on top of screen  102  at one side. Screen  102  is vibrated at a high frequency or oscillation by a motor or motors for the purpose of screening or separating the drilling mud on screen  102 . The liquid and fine particles will pass through screen  102  by force of gravity and be recovered underneath. Solid particles above a certain size migrate and vibrate across screen  102  where they are discharged. Screen  102  may include filtering elements attached to a screen frame (not shown). The filtering elements may further define the largest solid particle capable of passing therethrough. 
     In one embodiment, a screen frame may be formed from any material known in the art, for example, stainless steel, metal alloys, plastics, etc. In a preferred embodiment, the screen frame may be formed from a composite material. In this embodiment, the composite material may include high-strength plastic and glass, reinforced with steel rods. Composite screen frames may allow for more consistent manufacturing of the frame and may more evenly distribute mechanical stresses throughout the screen frame during operation. In another embodiment, screen frame may include composite material formed around a steel or wire frame. Additionally, the screen frame may be formed by injection molding. U.S. Pat. No. 6,759,000 discloses a method of forming a screen frame by injection molding, and is herein incorporated by reference in its entirety. For example, in one embodiment, a screen frame having a wire frame and a composite or polymer material, may be formed by first placing a reinforcing wire frame assembly including at least a first end, a second end, a first side, a second side, and at least one cross-member in a mold tool. 
     The mold tool may then be closed and liquid polymer may be injected into the mold tool (i.e., by injection molding) so as to encapsulate the wire frame and form an article having an open central region crisscrossed by transverse ribs bounding each side of the frame. An inward force may then be exerted on opposite faces of the wire frame assembly within the mold tool by fingers protruding inwardly from inside faces of the mold tool, the fingers being operable to engage the reinforcing wire frame when the mold tool closes. The fingers include inwardly projecting pegs that align with crossing points of wires to space the reinforcing wire frame from corresponding upper and lower internal surfaces of the mold tool, thereby ensuring that the reinforcing wire frame is buried within the polymer or composite material which is injected into the mold tool during the manufacturing process. The polymer or composite material is allowed to cure and then the screen frame may be removed from the mold tool. 
     In one embodiment, a plurality of shaker screens may be disposed in the shaker. As shown in  FIG. 2A , each shaker screen  200 A may include a screen frame  210 A and at least one filtering element (not shown). The at least one filtering element decreases the size of particulate matter that may pass through shaker screen  200 A. In such applications, the filtering element (not shown) may be attached to screen frame  210 A so as to limit the size of particulate matter which may pass therethrough. In one embodiment, the filtering element (not shown) may include, for example, a mesh, a fine screen cloth, or other materials known to one of ordinary skill in the art. Additionally, the filtering element (not shown) may be formed from plastics, metals, alloys, fiberglass, composites, and polytetrafluoroethylene. In certain embodiments, a plurality of layers of filtering elements (not shown) may be incorporated into one shaker screen  200 A to define a desired separation efficiency or cut. However, in alternate embodiments, the filtering element (not shown) may include a single layer (not shown). 
     Referring now to  FIGS. 2A-2C , in one embodiment, the plurality of shaker screens may form an interlocking system of shaker screens. An interlocking system of shaker screens may reduce or limit the amount of separation between the shaker screens, thereby reducing the gap or space unfiltered drilling fluid may leak through. One example of interlocking shaker screens is disclosed in U.S. Pat. No. 6,713,190, and is herein incorporated by reference in its entirety. In one embodiment, a first screen  200 A includes a screen frame  210 A having a groove  212  formed along at least a portion of a perimeter of an outer surface. The groove  212  includes an undercut portion  214  having an inclined underside  216 . A second screen  200 B disposed adjacent first screen  200 A in the vibratory shaker (not shown), may include a screen frame  210 B having a hooked protrusion  218  formed along at least a portion of a perimeter of an outer surface. Hooked protrusion  218  may include a ridge  220  configured to engage undercut portion  214  of first frame  210 A and an inclined portion  222  configured to engage inclined underside  216 .  FIG. 2C  shows first and second frames  210 A,  210 B assembled and interlocked. 
     Referring to  FIGS. 3A and 3B , a side view of a shaker screen  300  in accordance with an embodiment is shown. Shaker screen  300  is disposed on a support rail  306  and located below a bracing surface  308  attached to an inside wall  316  of a shaker basket (not shown). In this embodiment, shaker screen  300  includes a screen frame  310 . At least one filtering element (not shown), as discussed above, may also be attached to screen frame  310 . In one embodiment, an inflatable sealing element  302  is disposed along at least a portion of a perimeter of a top surface  304  of screen frame  310 . In this embodiment, a fluid may be injected into inflatable sealing element  302  through inlet  320 , thereby inflating inflatable sealing element  302  into sealing contact with bracing surface  308 , as shown in  FIG. 3B . One of ordinary skill in the art will appreciate that the fluid may be a gas (e.g., air), a liquid, or a gel. Inflation of inflatable sealing element  302 , and the corresponding sealing contact with bracing surface  308 , pushes shaker screen  300  downward into sealing engagement with support rail  306 . Thus, the need for typical wedge blocks may be eliminated. Additionally, inflatable sealing element  302  may reduce or prevent leakage of unfiltered drilling fluid over sides  318  of the shaker screen  300 . One of ordinary skill in the art will appreciate that in one embodiment, a wedge block may also be used in combination with a shaker screen having an inflatable sealing element, as disclosed herein, without departing from the scope of embodiments disclosed herein. 
     In an alternative embodiment, as shown in  FIG. 3C  (in an inflated state), an inflatable sealing element  302  may be disposed along at least a portion of a perimeter of a bottom surface  305  of screen frame  310 . In this embodiment, a fluid may be injected into inflatable sealing element  302  through inlet  320 , thereby inflating inflatable sealing element  302  and lifting the screen frame  310  into sealing contact with bracing surface  308 . Accordingly, inflation of inflatable sealing element  302 , and the corresponding sealing contact between the top surface  304  of screen frame  310  and bracing surface  308 , securely positions shaker screen  300  in the shaker (not shown). Additionally, inflatable sealing element  302  may reduce or prevent leakage of unfiltered drilling fluid over sides  318  of the shaker screen  300 . In yet other embodiments, an inflatable sealing element  302  may be disposed on a screen frame having an interlocking system like that discussed above in  FIGS. 2A-2C . 
     One of ordinary skill in the art will appreciate that in one embodiment, inflatable sealing element  302  may include one or multiple sealing elements disposed along a portion of the perimeter or along the entire perimeter of the top or bottom surface  304 ,  305  of shaker screen  300 . Further, inflatable sealing element  302  may be formed from any material known in the art including, but not limited to, rubbers, plastics, thermoplastic elastomers (“TPE”), foams, polychloroprene, polypropylene, nylon, mylar, composites, and/or any combinations thereof. 
     In one embodiment, inflatable sealing element  302  may be integrally formed with screen frame  310  of shaker screen  300 . In this embodiment, inflatable sealing element  302  may be positioned within an injection mold for screen frame  310 . Once the mold is sealed, a sealing element material (e.g., TPE) may be injected into the mold. The sealing element material may be allowed to cure, and then the screen frame including an integrally molded sealing element may be removed. One of ordinary skill in the art will realize that alternative methods of attaching a sealing element to a composite frame exist, for example, using an adhesive resin, and as such, are within the scope of the present disclosure. 
     In one embodiment, an air supply (not shown), for example, an air hose extending from an air pump, may be connected to inlet  320  to inject air into inflatable sealing element  302 . In one embodiment, where multiple shaker screens  300  are disposed in vibratory shaker  300 , each inflatable sealing element  302  disposed on each screen frame  310  may include inlet  320  and an outlet (not shown). The inlet  320  of a second screen frame may be in fluid connection with the outlet (not shown) of a first screen frame  310  by any means known in the art, for example, tubing, such that, when air is injected into the first inflatable sealing element  302  of the first screen frame, it also inflates the second inflatable sealing element of the second screen frame. An outlet of an inflatable sealing element may be sealed or capped to prevent air from leaking, thereby sealing the air within the sealing elements and allowing the inflatable sealing element  302  to inflate. 
     Referring now to  FIGS. 4A and 4B , a screen sealing system in accordance with embodiments disclosed herein is shown. In this embodiment, a first screen  400 A is disposed adjacent a second screen  400 B in a vibratory shaker (not shown). Shaker screens  400 A,  400 B include screen frames  410 A,  410 B, respectively. At least one filtering element (not shown), as discussed above, may be attached to each screen frame  410 A,  410 B. In one embodiment, a first inflatable sealing element  402 A is disposed along at least a portion of a perimeter of an outer surface  430  of first screen  400 A. As shown, inflatable sealing element  402 A may extend from top surface  404  to bottom surface  405  of screen frame  410 A. However, one of ordinary skill in the art will appreciate that first inflatable sealing element  402 A may extend along a selected portion between top surface  404  and bottom surface  405 . Furthermore, although shown to extend from a first side  422  to a second side  424  of screen frame  410 A, inflatable sealing element  402 A may extend along a selected portion or portions between first side  422  and second side  424 . Accordingly, the size and shape of inflatable sealing element  402 A may vary without departing from the scope of embodiments disclosed herein. 
     In the embodiment shown, a second inflatable sealing element  402 B is disposed along at least a portion of a perimeter of an outer surface  432  of second screen  400 B. Second inflatable sealing element  402 B is disposed proximate first inflatable sealing element  402 A. First inflatable sealing element  402 A has an inlet (not shown) and an outlet  440 . Similarly, second inflatable sealing element  402 B has an inlet  420  and an outlet (not shown). In this embodiment, the outlet  440  of first inflatable sealing element  402 A and the inlet  420  of the second inflatable sealing element  402 B are in fluid communication. The inflatable sealing elements  402 A,  402 B may be in fluid communication by any means known in the art. For example, as shown, a small piece of tubing  442  may connect the outlet  440  of first inflatable sealing element  402 A and the inlet  420  of the second inflatable sealing element  402 B. In one embodiment, the tubing  442  may threadedly connect the outlet  440  and inlet  420 . In this embodiment, the outlet (not shown) of the second inflatable sealing element  402 B may be sealed or capped so that the first and second inflatable sealing elements  402 A,  402 B inflate when a fluid is introduced to the inlet (not shown) of the first inflatable sealing element  402 A. One of ordinary skill in the art will appreciate that in certain embodiments, wherein a vibratory shaker includes a single shaker screen having a single inflatable sealing element, the inflatable sealing element may have a single inlet/outlet. One of ordinary skill in the art will also appreciate that a fluid may include a gas (e.g., air), a liquid, or a gel.  FIG. 4B  shows the first and second shaker screens  400 A,  400 B when the first and second inflatable sealing elements  402 A,  402 B are inflated. 
     In one embodiment, a fluid supply (not shown), for example, an air hose extending from an air pump, may be connected to inlet (not shown) to inject air into inflatable sealing element  402 A. The air passes through outlet  440  of first screen frame  410 A, through tubing  442 , and enters inlet  420  of second screen frame  410 B, thereby inflating second inflatable sealing element  402 B. An outlet (not shown) of a second inflatable sealing element  403 B may be sealed or capped to prevent air from leaking, thereby sealing the air within the first and second sealing elements  402 A,  402 B. 
     Referring now to  FIG. 5 , a perspective view of screen sealing system in accordance with another embodiment disclosed herein is shown. In this embodiment, a first screen  500 A is disposed adjacent a second screen  500 B in a vibratory shaker (not shown). Shaker screens  500 A,  500 B include screen frames  510 A,  510 B, respectively. At least one filtering element (not shown), as discussed above, may be attached to each screen frame  510 A,  510 B. In one embodiment, a first inflatable sealing element  502 A is disposed along at least a portion of a perimeter of an outer surface  530  of first screen  500 A. As shown, inflatable sealing element  502 A may extend from a top surface  504  to a bottom surface  505  of screen frame  510 . However, one of ordinary skill in the art will appreciate that first inflatable sealing element  502 A may also extend along a selected portion between top surface  504  and bottom surface  505 . Furthermore, although shown to extend from a first side  522  to a second side  524  of screen frame  410 A, inflatable sealing element  502 A may extend along a selected portion or portions between first side  422  and second side  424 . Accordingly, the size and shape of inflatable sealing element  402 A may vary without departing from the scope of embodiments disclosed herein. 
     In the embodiment shown, a second inflatable sealing element  502 B is disposed along at least a portion of a perimeter of an outer surface  532  of second screen  500 B. Second inflatable sealing element  502 B is disposed proximate first inflatable sealing element  502 A. First inflatable sealing element  502 A has an inlet (not shown) and an outlet  540 . Similarly, second inflatable sealing element  502 B has an inlet  520  and an outlet (not shown). In this embodiment, the outlet  540  of first inflatable sealing element  502 A and the inlet  520  of the second inflatable sealing element  502 B are in fluid communication. The inflatable sealing elements  502 A,  502 B may be in fluid communication by any means known in the art. For example, as shown, a small piece of tubing  542  may connect the outlet  540  of first inflatable sealing element  502 A and the inlet  520  of the second inflatable sealing element  502 B. In one embodiment, the tubing  542  may be threadedly connected to the outlet  540  and inlet  520 . 
     When inflated, first and second inflatable sealing elements  502 A,  502 B may engage in a male/female arrangement. As shown, first inflatable sealing element  502 A may have a substantially male connection shape, while second inflatable sealing element  502 B may have a substantially female connection shape. Accordingly, as a fluid is injected into inflatable sealing elements  502 A,  502 B, inflatable sealing elements  502 A,  502 B are inflated into sealing and interlocking engagement. Thus, leakage of unfiltered drilling fluid between adjacent shaker screens  500 A,  500 B may be reduced. 
     In one embodiment, a third inflatable sealing element  502 C may be disposed along at least a portion of a perimeter of an outer surface  534  of second screen  500 B. The third inflatable sealing element  502 C includes an inlet (not shown) and an outlet  546 . In this embodiment, the outlet (not shown) of the second inflatable sealing element  502 B is in fluid connection with the inlet (not shown) of the third inflatable sealing element  502 C. Inflatable sealing elements  502 B,  502 C may be in fluid communication by any means known in the art. For example, as shown, a piece of tubing  543  may connect the outlet (not shown) of second inflatable sealing element  502 B and the inlet (not shown) of the third inflatable sealing element  502 C. In one embodiment, the tubing  543  may be threadedly connected to the outlet (not shown) and/or inlet (not shown). In one embodiment, the outlet  546  of third inflatable sealing element  502 C may be sealed or capped so that first, second, and third inflatable sealing elements  502 A,  502 B,  502 C inflate when a fluid is introduced to the inlet (not shown) of the first inflatable sealing element  502 A. Note that  FIG. 5  shows the first and second shaker screens  500 A,  500 B when the first, second, and third inflatable sealing elements  502 A,  502 B,  502 C are inflated. Accordingly, when inflated, leakage of unfiltered drilling fluid between adjacent shaker screens  500 A,  500 B and/or between shaker screen  500 B and a wall of a shaker basket (not shown) may be reduced. 
     In one embodiment, a fluid supply (not shown), for example, an air hose extending from an air pump, may be connected to inlet (not shown) to inject air into inflatable sealing element  502 A. The air passes through outlet  540  of first screen frame  510 A, through tubing  542 , and enters inlet  520  of a second inflatable sealing element  502 B, thereby inflating second inflatable sealing element  502 B. The air then passes through an outlet (not shown) of second inflatable sealing element, through tubing  543 , and enters inlet (not shown) of third inflatable sealing element  502 C, thereby inflating third inflatable sealing element  502 C. An outlet (not shown) of third inflatable sealing element  502 C may be sealed or capped to prevent air from leaking, thereby sealing the air within the first, second, and third sealing elements  502 A,  502 B,  502 C. 
     Referring now to  FIG. 6 , a screen sealing system in accordance with embodiments disclosed herein is shown. In this embodiment, a first screen  600 A is disposed adjacent a second screen  600 B in a vibratory shaker (not shown). Shaker screens  600 A,  600 B include screen frames  610 A,  610 B, respectively. At least one filtering element (not shown), as discussed above, may be attached to each screen frame  610 A,  610 B. In one embodiment, a first inflatable sealing element  602 A is disposed along at least a portion of a perimeter of an outer surface  630  of first screen  600 A. As shown, inflatable sealing element  602 A may extend from top surface  604  to bottom surface  605  of screen frame  610 A. However, one of ordinary skill in the art will appreciate that first inflatable sealing element  602 A may extend along a selected portion between top surface  604  and bottom surface  605 . Furthermore, although shown to extend from a first side  622  to a second side  624  of screen frame  610 A, inflatable sealing element  602 A may extend along a selected portion or portions between first side  622  and second side  624 . Accordingly, the size and shape of inflatable sealing element  602 A may vary without departing from the scope of embodiments disclosed herein. 
     In the embodiment shown, a second inflatable sealing element  602 B is disposed along at least a portion of a perimeter of an outer surface  632  of second screen  600 B. In use, second inflatable sealing element  602 B may be disposed proximate first inflatable sealing element  602 A. First inflatable sealing element  602 A may have a plurality of inlets  670 ,  671  and at least one outlet  640 . Similarly, second inflatable sealing element  602 B may have at least one inlet (not shown) and at least one outlet  685 . In this embodiment, the outlet  640  of first inflatable sealing element  602 A and inlet (not shown) of the second inflatable sealing element  602 B are in fluid communication. Additionally, the outlet  685  of second inflatable sealing element  602 B is in fluid communication with the inlet  670  of first inflatable sealing element  602 A. The inflatable sealing elements  602 A,  602 B may be in fluid communication by any means known in the art. For example, as shown, outlets  640 ,  685  may include molded fittings known in the art that may be, for example, co-molded with, insert-molded with, or attached to inflatable sealing elements  602 A,  602 B. 
     Examples of molded fitting are shown in  FIG. 7 . One of ordinary skill in the art will appreciate that fittings  701 ,  702  may include two or more ends configured to couple two or more components (e.g., inflatable sealing elements) together. For example, in one embodiment, a first end  790  of fitting  701  may be coupled to first inflatable sealing elements  602 A ( FIG. 6 ) by any method know in the art. For example, fitting  701  may be co-molded, insert-molded, or attached by an adhesive or other known methods of attachment to first inflatable sealing element  602 A. A second end  792  of fitting  701  is configured to engage an inlet (not shown) of second inflatable sealing element  602 B. Thus, when air is injected into first inflatable sealing element  602 A, for example, through inlet  671 , air inflates first inflatable sealing element  602 A and passes through outlet  640 , which may include fitting  701 . Air passing through outlet  640  may then enter second inflatable sealing element  602 B, thereby inflating second inflatable sealing element  602 B. 
     In another embodiment, a fitting may include three ends, for example, fitting  702 . Fitting  702  may used to couple at least three components together. In one embodiment, fitting  702  may be coupled to first inflatable sealing element  602 A by any method known in the art, as discussed above. A first end  772  may be configured to inject air into first inflatable sealing element  602 A. A second end  774  may be configured to engage the inlet (not shown) of second inflatable sealing element  602 B, while a third end  770  may be configured to engage an inlet (not shown) of a third inflatable sealing element (not shown), or alternatively, to receive air from an air supply. 
     One of ordinary skill in the art will appreciate that fittings  701 ,  702  may be used to couple inflatable sealing elements of any of the embodiments disclosed herein, for example, the inflatable sealing elements shown in  FIGS. 3-5 . Fittings  701 ,  702  may provide fluid communication between a first inflatable sealing element and any adjacent inflatable sealing element. As shown, when assembled and fitted into a corresponding opening or complementary fitting, fittings  701 ,  702  may provide a sealed pathway for air to flow from a first inflatable sealing element to a second inflatable sealing element. One of ordinary skill in the art will appreciate that fittings  701 ,  702  may be formed from any material known in the art, including, but not limited to, rubbers, plastics, thermoplastic elastomers (“TPE”), polychloroprene, polypropylene, nylon, mylar, composites, and/or any combinations thereof. 
     Referring back to  FIG. 6 , as shown, inlets  670  may include, for example, a tubular opening or a one-way valve configured to receive outlets  640 ,  685 , thereby forming a seal around outlets  640 ,  685 . One or ordinary skill in the art will appreciate that any other male/female type configuration (e.g., threadedly connected) may be used without departing from the scope of embodiments disclosed herein. 
     In one embodiment, a fluid supply (not shown), for example, an air hose extending from an air pump, may be connected to inlet  671  to inject air into inflatable sealing element  602 A. The air may pass through outlet  640  of first screen frame  610 A and into inlet (not shown) of second screen frame  610 B, thereby inflating both first and second inflatable sealing elements  602 A,  602 B. 
     One of ordinary skill in the art will appreciate that a plurality of shaker screens may be disposed within a vibratory shaker. Each shaker screen having a screen frame may include an inflatable sealing element disposed thereon. Accordingly, one of ordinary skill in the art will appreciate that a plurality of inflatable sealing elements may be used in accordance with embodiments disclosed herein. In one embodiment, a shaker screen may have one, two, three, or any number of inflatable sealing elements. In another embodiment a sealing system may include one, two, three, or any number of shaker screens, each having one, two, three, or any number of inflatable sealing elements in sealing engagement. Accordingly, the number, shape, and/or size of the shaker screen or inflatable sealing element may vary without departing from scope of embodiments disclosed herein. 
     Advantageously, embodiments disclosed herein may provide a more efficient seal for a screen frame assembly within a shale shaker. Some embodiments may provide a more efficient interlocking sealing system. Further, embodiments disclosed herein may reduce the amount of unfiltered drilling fluids and drilling particulates from bypassing the screen frames disposed in a shale shaker. 
     While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.