Field of the Invention

The present invention is directed to shale shaker screen retention rails, placed in the interior of a shale shaker basket, and reciprocating rail receiving and securing channels on a shaker screen, forming a system for the alignment, positioning and securing of a shale shaker screen within a shale shaker basket wherein said screen acts as a primary filtering tool of a shale shaker for removal of solids from a solids burdened drilling fluid, generally. Specifically, said interiorly placed shale shaker rails receive, support and guide an inserted screen, via reciprocating channels, whereby said screen is guided within or by said basket rails and said basket rails align and receive said screen. Further, pressure and/or wedges may be applied above or below said shale shaker screen whereby placement is secured, screen movement is restricted, and bypass of materials is precluded via tightly managed seals.

Background

Shale shakers are commonly considered the first, and most important, phase of solids control. Shale shakers, via attached screens, are responsible for filtering and removing large solids particles from various removed subsurface sources as well as in certain separation and recycling procedures in various waste sorting plants. Indeed, given the criticality of their utility, measured in retained and sequestered materials, it is easy to see that the role shale shakers play in solids control cannot be overstated.

Shale shakers themselves are devices instituted for particle filtering and separation via a vibratory means wherein, through intense vibratory motion and oscillation, material containing liquids are placed upon a horizontally positioned, porous screen where large to medium “coarse” particles are manually separated from drilling fluids where the resultant desired liquid medium is segregated from undesired materials (cuttings and formation). In the case of mining, the desired materials are coal or valuable minerals whereas, in the case of petroleum drilling, the desired material is reclaimed drilling fluid.

And, while shale shakers overwhelmingly find their primary use in petroleum exploration and production, other industries requiring solids removal utilize shale shakers and their screening mechanisms for various solids removal processes. Shale shaker utilization in the mining industry rely heavily on screening devices with linear or circular vibration and fine screening capabilities as an efficient means of procuring coal and precious metals. As well, the processing industry also utilizes screening and shaker equipment in a variety of separation applications integral to process flows for an efficient means to separate unwanted materials from desired materials. Yet, it is the petrochemical industry which evidences the lion’s share of use of solid waste removal.

As reported by the American Petroleum Institute (API), it is estimated for every foot of well drilled approximately 1.2 barrels of waste drilling “mud” is generated. The effect of drilling waste on drilling efficiency, productivity and cost is a principal concern for the energy production industry. Waste and solids control, and associated potential detrimental environmental impacts (and associated liabilities), have become a primary motivator for increasingly effective solids control up to and including the most effective use of solids control equipment (e.g., shale shakers, screens), and related equipment, which includes focusing on an efficient, well-maintained shale shaker system.

Clearly, drilling fluids are vital to the recovery of petrochemicals in the oil and gas industry serving primarily the functions of maintaining pressure within the borehole, maintaining a cooled, clean drill bit, suspending cuttings in fluid and carrying cuttings away from a drilled well. Specifically, on a drilling rig, used or spent drilling fluids are pumped from “mud pits”, through the drill string and out of the drill bit (effectuating cooling, lubricating and cleaning of the drill bit) where the drill bit accomplishes the grinding of formation rocks and creation of a hole, well or bore. Once the drilling fluid exists the drill bit, the drilling fluid acts to create positive pressure on the surrounding formation which disallows a rush of fluid exiting the formation to enter the borehole. This pressure, a hydrostatic pressure, allows, in addition to inhibition of influx of formation fluids, the capture of cuttings and transport of these cuttings to the surface for removal from the borehole. Once out of the borehole, the cuttings-ladened fluid is deposited into the baskets of a shale shaker (specifically the screens inserted into the basket base itself) which then filter the drilling fluid, through the basket screens, which are finally deposited (or redeposited) into “mud” tanks for collection, fine particle removal and eventual reuse.

It is therefore evident that the integrity of the entire drilling system (i.e., the ability to maintain borehole integrity, repeatedly evacuating the borehole, drilling bit maintenance and upkeep, capture, filtering and reuse of drilling fluids) is directly dependent upon the durability and stability of a functional screening system - namely shaker screens. Manifestly, it has become more and more evident that the durability of and wear experienced by shale shaker screens across all industries has become, and will persist, as a major limiting factor of the integrity and longevity of each individual shale shakers’ functionality.

And, just as shale shakers are essential components of petrochemical procurement as a critical solids controller of solids-ladened drilling “mud”, their maintenance and functional preservation can be seen as nothing short of paramount for oil drilling and production. Expressly in the petroleum industry, and most directed to the present invention, shale shaker screens are the first and most crucial phase of a solids material control, management and removal systems in both on shore and offshore drilling. These shale shakers are utilized to remove large, coarse solids (cuttings) from the drilling fluid (or drilling "mud") before recycling and reusing the fluid. As evidenced in several variations, including linear motion shale shakers, circular motion shale shakers and balanced elliptical motion shale shakers, regardless of method of use, all shale shaker screens in petrochemical removal and refining serve the primary function of separating solid particles from a liquid medium (e.g., “cuttings” and debris from drilling fluid or drilling “mud”) in an effort to filter, to the greatest extent possible, particulates from the fluid to reuse drilling mud in one of several capacities in drilling operations.

In oil and gas drilling, drilling fluids are integral to the drilling process and, as referenced above, serve to (1) provide positive, hydrostatic pressure within the well, (2) maintain the integrity of a well (3) lubricate and cool the drill bit, (4) maintain a clear and clean drill bit and (5) suspend and convey drilled cuttings away from the bore hole and to the formation surface - the latter being the most pertinent to the use and usefulness of the shale shaker screens. The fluids themselves can be a mixture of various chemicals in liquid (e.g., a water-based solution, an oil-based solution, a synthetic based solution or a combination thereof). This liquid can be both caustic to handle and expensive to manufacture. For both environmental and economic reasons, drilling fluid loss is abated by separating drilling fluid from retrieved drilled cuttings and formation particulates thereby allowing for the recovery of the fluid before recycling and reusing the drilling fluid within a given system. The removal of the greatest quantity of coarse solids (as well as successive processing of finer-grained solids) on the first circulation of mud from the well is important before any subsequent reintroduction into the well can be initiated as drilling solids containing even a small amount of fine particles reintroduced into the well have the potential to be detrimental the functional components of drilling equipment. The wear and damage to these parts may adversely affect well integrity, rig productivity, production costs and worker safety.

Specifically, in operation, after introduction of drilling fluids into the well borehole for their intended purpose, solids infused drilling fluids are then returned to the surface and these “used” or “spent” drilling fluids are made to flow directly into the basket of shale shakers. Here the fluids are then separated into liquid and solid particles through vibration and gravity. Liquid is then pulled, via gravity, through shale shaker filter screens and deposited into large collection reservoirs (i.e., “mud tanks”) as solids are laterally conveyed along shale shaker decks atop shaker filters and through discharge ports for collection and further processing. Concisely, after the drilling fluid is introduced onto the shale shaker deck (flats), vibration of the shaker basket (s) and gravitational pull are used to separate suspended solid particles from the drilling fluid accordingly. Once processed by the shale shakers, the drilling fluid is collected in mud tanks where other solid control equipment conventionally begins the process of removing ever finer solids from the drilling fluid. Once solids removed by the shale shaker are guided out of a discharge port, these solids are segregated into holding tanks where the solid particles may undergo additional treatment before eventual disposal. The drilling fluid, once cleared of solid particles, is then reprocessed and reintroduced back into the system to begin the process once again.

Thus, with regards to freedom from suspended solids, there remains a direct correlation between the operational condition of shale shaker screens, their secured placement and the relative purity of drilling fluid. Drilling fluids are dependent on an operationally efficient shale shaker screens and that shale shaker’s ability to successfully and efficiently separate drilling fluid from solids material with limited to no seepage. Consequently, it is the efficacy of the shale shaker at removing solid particles and minimizing bypass that leads to cleaner drilling fluids and allows for better functioning oil field equipment thus producing a reusable mud that results in overall net safety, more efficient production and substantial cost avoidance.

Structurally, shale shakers consist of a hopper, a feeder, a basket and various mechanical means of vibrating the bed (deck/flat) (and shifting the angle of the basket) all in an effort to sift solid materials away from drilling fluids in the most productive manner. The hopper, also known as the "base", serves as both a platform for the shaker and collection pan for the fluid processed by the shaker screens. The feeder is essentially a collection pan for the drilling fluid before it is processed by the shale shaker’s basket and screen. The drilling fluid enters the feeder and fills the feeder to a predetermined point whereby the drilling fluid spills over the feeder and onto the screening area of the shaker. The screen basket or "bed" is the most significant functioning part of the machine, as it is responsible for transferring the vibratory intensity of the machine, measured in multiples of "G's", throughout the entirety of the basket. The shale shaker’s vibratory mechanism transfers momentum and energy to the screen basket where the shaker filter screen is held securely in place and is utilized to remove drilled solids from the drilling fluid. Different shale shakers have different means by which the demands of solid separation are accomplished using screen tensioning apparatuses, specifically designed seals around the screens, basket reinforcements to increase basket integrity and special float mounts together with rubber deck seals and selective vibrators (motors) operating at variable speeds and vibratory intensities. In addition to vibration, the shaker basket must be capable of shifting its angle and position (proportional to the flow rate of the drilling fluid) to accommodate various flow rates of drilling fluids and to ensure that the entire area of the shaker bed (screen surface area) is utilized via an angling mechanism (be it mechanical, pneumatic or hydraulic). The drilling fluid flowing over the shaker bed is maintained in two states - the pool and the beach. The pool is the area of the screening deck that consists mostly of drilling fluid (in combination with drilled cuttings) while the beach is the area where the drilling fluid has been mostly removed from the cuttings and begins to form areas of aggregated solids. The ratio of pool to beach is typically maintained at approximately a 20:80 ratio depending on the requirements of cutting dryness and flow rates. The wire, cloth or wire-and-cloth mesh of the shale shaker screen acts as a sieve, with the created vibration as the driving force, to receive and filter the drilling fluid through screen mesh allowing movement into accepting “mud tanks” below for subsequent processing. The aforementioned angling mechanisms can be implemented to not only position the accepted “mud” about the deck recovery area (in order to obviate points of saturation), but also to employ the entirety of the shaker bed, in conjunction with the vibratory force, to create a linear, unbalanced, elliptical and/or circular motion with which to further accelerate fluid recovery and maximize shale shaker efficiency.

Manifestly, a properly maintained, positioned and functioning shale shaker screen is key to efficient solids removal and mud recycling where the “health” of the screen is directly attributable, monitored and accessed at the primary area of vibration absorption and surfaces contact: the shale shaker basket (consisting of the deck/flat and shale shaker screen). Prone to the most intense frictional wear, these most functional components of a shale shaker are equally capable of the greatest amount of remedy in terms of decreasing basket wear and extending shale shaker screen, as well as basket, longevity.

While the basket frame and shale shaker screens themselves are subject to modification, relatively, in terms of shape, number and size of interior panels (in order to maintain support integrity and optimize fluid flow-through while maintaining the maximum accessible surface area), most screens are of a uniformly square or rectangular conformation. Further, the mesh, or porous portion of a screen, consisting primarily of cloth and metal, strike a balance between fluid conductance and permeability, on the one hand, and insuring materials integrity and durability (and overall mesh lifespan) on the other. Equally, a variety of tensioners, wedges and wear items may be used to compress the shape of a screen to a convex or concave contour in an effort to secure and position such screens in an effort to positively effectuate throughput and/or screen life.

Typically, screens are designed with multiple layers of mesh over a robust backing of cloth, metal (or a combination of the two) to further protect the screen itself against solids-loading and eventual wear and tear. Yet, in addition to screen construction, various other factors are important to consider in terms of functionality and utility. These factors include the use of several overlapping mesh layers, mesh pore sizes, layer thickness and overall number of screens utilized in tandem and series. Specifically, with reference to mesh pore size, this is measured through ‘API size’ or sieve equivalent where the API designates the largest particle size that would pass through the screen and/or the smallest particle size that the screen is capable of capturing. Further mesh thickness and number and size of exposed and available panels, each acting as mesh conductance resistance barriers, have a direct effect on the longevity of a shaker screen. Clearly, replacement of the shaker screens, and/or shaker screen assemblies (including wear items and deck flats), hold the key and greatest potential for increased shaker basket efficiency, solids separation productivity and cost savings. Just as screens are the most replaced and replaceable part of the shale shaker, shale shaker baskets, and the eventual wear experienced at the basket, garners a second, yet correspondingly important, albeit less conveniently amendable, area of remediation. Although replacement is less frequent, removing a worn basket and replacing that basket with a new basket nonetheless becomes inevitable with use and garners great expense. Although occurring at a reduced rate as compared with shale screen replacement, basket replacement is eventually necessitated and becomes increasingly probable with use. The logistics of basket replacement and semi-permanence of the basket itself, creates an untenable cost not only in terms of actual replacement but also in terms of disruptions in production with necessitated shale shaker transport to designated on shore facilities or shops for repair and replacement.

Therefore, it is the goal of the inventor to address the primary issues faced by shale shaker operators - that of shaker screens’ secured placement and retention where alignment, placement and securing to the interior of a shaker basket is currently inexact, lacking in uniformity and suffering from deficiencies in insertion, removal and secured conformation. This imprecise placement leads to increased motion and vibratory-induced wear, resultant fluid seepage, and accelerated screen (and basket) wear ultimately necessitating premature, and cost incurring, replacement. Continuous wear itself results directly from improperly fitting shale shaker screens that (1) have the potential to damage a receiving basket, (2) correspondingly damage the shale shaker screen, (3) create separation between basket and screens and (4) create a feedback loop of increased damage and separation, unwanted solids translocation across defective (warped) screen edges (and mesh) or bypassing screens altogether due to non-contiguous contact with a basket’s interior. Larger and larger volumes of by-pass, low gravity/fine solids (and eventually large solids) build-up in the active mud system creating greater downstream pressure on mechanical separation mechanisms as a direct result of worn screens, screen misalignment and increased space between screens and shaker baskets.

Ultimately, unwanted solids materials accumulate in the system (mud pits) which subsequently cause increased wear on pumps, down hole motors, and bottom hole assemblies progressively compromising the integrity and safety of downhole equipment and the wellbore itself. Such drilling fluid contamination leads to increased risk of mechanical failure, increased cost of the drilling and, in due course, decreased and/or more costly petroleum production. What’s more, when direct damage occurs to the interior of the basket, through misaligned and ill-fitting screens, such damage requires screen removal for replacement and/or basket removal for repair requiring transporting to a repair facility or welding and repair on site. This process is costly, sometimes averaging well over 50% the cost of a new basket. The wear on the basket causes drilling contractors to experience nonproductive downtime cascading toward wasted resources through an inability to operate the shaker resulting in (a) incurred cost to repair the shaker basket, (b) increased cost due to idle machinery and personnel and (c) lost and/or diminished recovery and production.

It is therefore inventor’s goal to remediate infirmities described in the prior art and to focus on unaddressed, long-felt deficiencies in the field of petrochemical recovery by extending the operable lifespan of solid waste control equipment, specifically shale shaker baskets and screens, by implementing a two component system: a shale shaker screen retention rail, placed on the interior of a shale shaker basket, together with reciprocating screen channels, on either side, right and left side, of a shaker screen, for the alignment, positioning and securing of a shale shaker screen. Alternatively, said retention rail may be exhibited on the exterior of a shale shaker basket screen and said reciprocating channel may exist on the interior of said shale shaker basket. This two-component (rail and channel) system allows for the proper alignment, placement and securing of a shale shaker screen, enhancing its ability to maximize utility as a primary filtering tool of a shale shaker for removal of solids from solids burdened drilling fluid. Further, once said basket retention rails and screen side rails are aligned, and the screen is securedly positioned, a wedge or, as detailed herein, a bladder system may be used to further secure said screen to said basket’s interior and further enhance barriers to fluid bypass, directly and indirectly, at several key junctures within the present invention and system while in operation.

Summary of the Invention

The present invention relates to a cross-sectional square, round, symmetrical, asymmetrical, angular or other specifically shaped protrusion made to run into a reciprocating channel thereby creating a ‘protrusion and accepting channel (or groove)’ combination where said protrusion (e.g., rail) may exist on the interior of said shaker deck and said accepting channel may exist on the exterior of a shale shaker screen, or vice versa, by which a shale shaker screen may be inserted into/attached onto the shale shaker basket interior securedly. This may be accomplished by (a) inserting a protruding portion (e.g., a rail) exhibited along the inner portion of the shale shaker basket (top, bottom or side) and along each side length of a shaker screen’s edges made to run into an accepting channel of a basket deck’s interior or, alternatively, by (b) inserting a shaker screen into the interior of a shaker basket whereby said basket interior exhibits said channel within said its interior right and left sides and said screen exhibits a reciprocal rail for insertion into said reciprocal channel. Succinctly, male (protrusion) and female accepting (groove) parts can be either (1) male-basket and female-screen, (2) female-basket and male screen or a combination thereof wherein the left side of a screen may be male-basket, female screen and the right side may be female-basket, male-screen or vice versa. Such a protrusion and accepting channel combination may be pinned, welded, bolted, or fastened to the basket interior upon original construction or via a retrofit where it is contemplated that an accepting channel or groove (female-type channel) may run along the inner surface of a shale shaker basket (where a shale shaker screen exhibits a male/protruded portion for mating to said basket channel). Where rails exist in a shale shaker basket and on said decks, screens should be constructed to exhibit a corresponding channel into said screen’s body. Where channels exist in a deck or flat, rails should be constructed into screens. What is more, a wedge or pneumatic bladder may be utilized to (a) further depress said screen to decks (b) properly align an inserted screen, (c) decrease vibratory frictional wear and (d) obviate avenues for bypass thereby decreasing seepage, supporting efficient filtering and enhancing screen lifespan.

More specific to construction, a basket could be designed or retrofitted to display a “male” protrusion (e.g., a cylinder shape) running the inner length of a basket’s interior sidewalls which is made to be accepted by a “C”-shaped channel (e.g., a hollowed half or ³ /4, open-ended cylinder on a shaker screen) or a “C”-shaped channel may be exhibited on the interior length of said shaker basket and said shaker screen may exhibit a protrusion which is cylinder shaped. Yet, it is in the contemplation of inventors to have a basket and shaker combination wherein male protrusions and female accepting channels may exist in opposite conformations on either side (i.e., male-basket/ female-screen left and male-screen/female-basket right). It is also contemplated by inventors that the male shape, residing on either the basket interior or screen edge may be a square shape, “cross” shape, multi-angular shape or any other rounded or angular shape capable of communicating with a reciprocal “female” and corresponding shape. Ultimately, though, the basket and screen are mated as to provide securement, stability and, most importantly, disallowing of fluid to pass (bypass) between basket and screen during high oscillations, maximum flow and peak vibrations.

The screen may exhibit an indention, channel or “cut out” on the bottom of the screen frame, top of the screen frame or side of a screen frame so long as said channel is mated to a reciprocating protrusion in the basket railing. Where the opposite is true, and a protrusion exists on a screen, that protrusion may exist on the bottom, top or side of said screen and a receiving channel may be positioned to mirror the protrusion. For example, a protrusion existing on the bottom of a screen will mate with a channel of a shaker basket similarly inferiorly placed. Ultimately, though, this designation is mutable so long as when the basket interior and screen exterior are mated together, corresponding and reciprocal segments (components) mate and each fit tightly and securely together with limited to no space existing between the two. Additionally, a wedge, pneumatic air bag or other tension device may be as well used thereby creating pressure and pushing down (up or in) on the screen to create a more secure placement, an even tighter seal or a combination thereof.

By decreasing the distance between the shale shaker screen and basket interior, wear upon the functional shaker basket system components are decreased, the present invention thereby acts by securing screen to basket and decreasing wear, simultaneously, on shaker screens and shaker baskets resulting in the extended longevity of each component. The present two-part, rail and channel system that is the present invention is designed and implemented in such a way as to allow for the shaker basket and shaker screen to create a contiguous barrier between primary functioning parts of the shale shaker basket assemblage which avoids friction and uniformly absorbs vibration. The screen and basket rail and channel system remains firmly fastened to the interior of a shale shaker basket, semi-permanently, having the capability to be easily placed and replaced into the basket of the shale shaker which can be maintained in a secure conformation and alignment until such time as removal becomes a necessity. The semi-permanent, secured placement or “locking” of a shaker screen within the interior of a shale shaker basket is capable of withstanding tension, angling and vibratory motions exerted on shaker baskets frames and screens greatly in excess of present implementations and systems. Traditional basket and screen combinations do not exhibit the same capacity for strict alignment, secured placement and limited separation distances. Once the present invention is eventually does wear and fails to operate according to requirements (e.g., said vibration, angling and extended use causes warping of the screen and/or direct wear on the basket causing solids and fluid seepage to bypass the system), the present invention’s screen may be replaced at a fraction of the cost of replacing an entire shale shaker basket or costly repair in refurbishing a basket thereby obviating any removal of the shaker basket from the solids control system workflow. Additionally, shaker screens, subject to much less operational stress with the implementation of the present invention, necessitate fewer replacements due to increased wherewithal and endurance in the present reciprocal rail configuration.

Long-term advantages of the implementation of the present screen and basket rail and channel system between the shale shaker basket and screen results in the near total exclusion of large particle solids, as well as very few small particle solids, introduction into mud tanks where space between the shaker basket and shaker screen is so de minimis as to work to preclude practically all bypass. Here, prevention of wear is not directly at the site of attachment and not immediately perceived, as in the prior art, but removed from the location of basket interior and screen side rails and attenuated. Here wear, and impending disfunction, is further prevented wherein a drilling system’s functional components (e.g., drill strings, drill bits and pumps) avoid detrimental contact with partially or poorly filtered recycled drilling fluid and inevitable damage to internals. Therefore, by installing the present invention between the shale shaker basket and shaker screen, several advantages become readily apparent including fewer screen and shaker basket deck replacements, practically complete elimination of bypass of high gravity solids, great exclusion of low gravity solids through mud bypass, fewer shaker basket rebuilds, less downstream equipment damage, decreased equipment failure, reduced non-productive time and diminishing of overall costs while increasing productivity and net worker safety. In terms of placement, positioning and adherence, the present invention can be installed on new shale shaker baskets prior to distribution from the factory or retrofitted onto existing shale shaker baskets (of various dimensions and constructs) and may be used simply and easily for prevention of excessively worn shaker baskets, shaker screens (and related wear items), obviating frequent screen replacements, retrofits and/or replacements. Once shale shaker basket decks are designed and implemented with the present invention, shale shaker screens may be subsequently manufactured to form the reciprocal (e.g., rails for channels or channels for rails that exhibit reciprocating structures). What is more, the present invention can be utilized as a “seal” and “barrier” which acts to prevent solids entry into mud tanks via worn shaker decks, shaker baskets, ill-fitting screens and ineffectual wedges and wear items causing certain wear and detachment, creating untoward separation and serving to grant access to increasingly larger solids into the solids control system stream surreptitiously, insidiously and undesirably.

Brief Description of the Drawings

While the novel features and method of use of the application are set forth above, the application itself, as well as a preferred mode of use, and advantages thereof, will best be understood by referencing to the following detailed description when read in conjunction with the accompanying drawings in view of the appended claims, wherein:

FIG. 1 depicts a typical prior art shale shaker.

FIG. 2 illustrates the present invention incorporated into Prior Art FIG. 1.

FIG. 3A is the present invention providing a basis for an exploded view.

FIG. 3B shows an enhanced view of FIG. 3A.

FIG. 4 illustrates one preferred embodiment of the present rail and channel system invention. FIG. 5 depicts another preferred embodiment of the present invention.

FIG. 6 illustrates yet another preferred embodiment of the present invention.

FIG. 7 shows another preferred embodiment of the present invention.

FIG. 8 is another preferred embodiment of the present invention and inserted bladder.

FIG. 9 is a removed bladder system for the securing of the present invention.

And while the invention itself and method of use are amendable to various modifications and alternative configurations, specific embodiments thereof have been shown by way of example in the drawings and are herein described in adequate detail to teach those having skill in the art how to make and practice the same. It should, however, be understood that the above description and preferred embodiments disclosed, are not intended to limit the invention to the particular embodiment disclosed, but on the contrary, the invention disclosure is intended to cover all modifications, alternatives and equivalents falling within the spirit and scope of the invention as defined within the claim’s broadest reasonable interpretation consistent with the specification.

Detailed Description

Detailed description of the preferred embodiments of the invention are disclosed and described below. Yet, each and every possible feature, within the limits of the specification, are not disclosed as various permutations are envisioned to be within the purview and contemplation of inventor and understood to those having skill in the art. It is therefore possible for those having skill in the art to practice the disclosed invention while observing that certain placement and spatial arrangements are relative and capable of being arranged and rearranged at various points about the present invention that nonetheless accomplishes to remedy one or more of the infirmities as outlined and discussed above in the field of solids control and management, generally, and shaker screen placement, alignment and securing, specifically. Patently, the size and shape of certain features may be expanded or narrowed to accommodate each individual shaker basket and screen and may be customizable to suit various and variable screen sizes, screen shapes, basket rails’ and screen rails’ configurations while maintaining the underlying functionality of the present invention.

Equally, it should be observed that the present invention can be understood, in terms of both structure and function, from the accompanying disclosure, diagrams and claims, taken in context with the associated drawings. And whereas the present invention and method of use are capable of several different embodiments, which can be arranged and rearranged into several configurations, each may exhibit accompanying interchangeable functionalities without departing from the scope and spirit of the present application as shown and described.

As depicted in FIG. 1, a prior art shale shaker 10 generally comprises an open bottomed shaker basket 15 having one open discharge end 20 and a solid walled feed end 25 consisting of a feeder 65 wherein drilling fluid 63 is pooled and collected before processing. A number of (typically) rectangular screens (here upper screen 30a and lower screen 30b) are arranged in a shaker screen basket 15 which is characteristically held in by C-channel rails (not shown) or wedge brackets 35 and wedges 40 (see generally FIG. 4) located on the shale shaker basket 15 walls or by using a hook-strip connection means (not shown). The shale shaker basket 15 itself is arranged on top of springs 50 above a receptacle for receiving recovered drilling mud (not shown). A “skip” or “ditch” is provided beneath the open discharge end 20 of the shale shaker basket 15. A motor or motors 55 are affixed to the shale shaker basket mounting plate 60, which has a drive rotor provided typically with an offset internalized clump weight. In use, the motor 55 rotates the rotor and the offset clump weight which causes the shale shaker basket 15 and the screens 30a and 30b fixed thereto to vibrate or “shake” at velocity and high RPMs. Solids ladened mud 63 is introduced at the feed end 65 of the shale shaker basket 15 and onto the screens 30a and 30b. The shaking motion induces the solids 70 to move along the screens 30a and 30b towards the open discharge end 20. Drilling mud 63 passes through the screens 30a and 30b leaving particulate solids 70 on the surface of the screen for eventual egress from the open discharge end 20. The recovered drilling mud is received in the mud tanks for further processing and the solids 70 pass over the discharge end 20 of the shale shaker basket 15 into the “ditch” or “skip”. The screens 30a and 30b are generally of one of two types: hook-strip or pre-tensioned.

The hook-strip type of screen 30 comprises several rectangular layers of mesh layered or stacked in a “sandwich” orientation, usually comprising one or two layers of fine grade mesh and a supporting mesh having larger mesh holes and heavier gauge wire. The layers of mesh are joined at each side edge by a strip which is in the form of an elongate hook. In use, the elongate hook is attached to a tensioning device arranged along each side of a shale shaker 10. The shale shaker 10 further comprises a crowned set of supporting members, which run along the length of the basket 15 of the shale shaker 10, over which the layers of mesh are held taught or “tensioned”. The supporting mesh may be provided with or replaced by a panel having apertures therein.

The pre-tensioned type of screen 30a and 30b, 400 (See FIG. 4) comprises several rectangular layers of mesh, usually also comprising one or two layers of fine grade mesh and a supporting mesh, having larger mesh holes and heavier gauge wire. The layers of mesh are pretensioned on a rigid support comprised of a rectangular-angled, iron frame and adhered thereto. The screen is then inserted into C-channel rails arranged in a shale shaker basket 15 of a shale shaker 10. Customarily, it is desirable to maximize vibration of the screen(s) 30 while isolating equipment, objects, and structures adjacent the vibratory separator from the intense vibrations and oscillations produced by the vibrating apparatus. Such isolation is affected by using springs 50, rubber, rubber-like or resilient members or cushions, isolator apparatus, and shock absorbers on which the container or shale shaker basket 15 is mounted. But functional parts of the shale shaker 10 (e.g., the shale shaker basket 15, shaker deck grid 75 and screen 30) cannot be protected from all vibration (and or exterior environmental forces) and deterioration, wear, erosion, rust, corrosion and fretting will ultimately prevail. The present invention 400 seeks to address the remediation of eventual wear on the moving parts of a shale shaker 10 and shale shaker basket 15 through a placeable and replaceable present invention that is shale shaker basket rail system and methods of removal, replacement and installation thereof.

As presented in FIGS. 1 - 8, the present invention shale shaker screens 30A and 30B, 400 are a largely flat, rectangular-shaped sieve-type screen which sits atop of a shaker deck’s (shaker flat’s) grids 420 (See specifically FIG. 4) and within the shale shaker basket 15. The shaker screens (30a and 30b as shown generally in FIG 1 - 3B and 400 of FIGS. 4-8) are then placed atop a shaker’s decks 420 or, alternatively, on top of a shale shaker basket buffer and wear reduction barrier (as described in U.S. Pat. Application No. 16,439,438) creating a layered or “sandwiched” system of shaker deck 420 / shale shaker basket buffer and wear reduction barrier (not shown)/shaker screen 400, from bottom to top, that allows the present invention to act as a combination “vibrational barrier” and “frictional barrier” between the shale shakers functional components (i.e., shaker screen 30a, 30b, 400 and shaker deck 420).

Many typical vibratory separators and shale shakers exhibit a basket 15 to which is secured one or more screens 30 used for separating components of material fed to the vibratory separator or shale shaker 10. The vibrating apparatus 55 connected to the shale shaker basket 15 vibrates the basket 15 and the vibrations are imparted to a screen or screens 30A and 30B, 400 secured therein.

In one preferred embodiment, as illustrated in FIGS. 4, the present invention may be a cross-sectional “square” rail 430 (which may alternatively be another specifically-shaped protrusion as described herein with a corresponding receiving shape) adhered to the deck 420 of a shale shaker 10 which is made to run into a reciprocating channel 450, exhibited within the body of said shaker screen 400, thereby creating a protrusion (rail 430) and accepting channel (reciprocating channel 450). Additionally, the term “square” is defined wherein the cross section of the present rail 430 is illustrated as being exposed on exactly 3 sides (wherein the inferior side is defined by the point of connection between said rail 430 and the deck flat 420) Expressly, as shown and described, said reciprocating channel’s 450 interior dimensions are only slightly larger than the exterior dimensions of said square rail 430 providing for ease of insertion and adjustment of said rail 430 into said reciprocating channel 450.

It is further within the contemplation of inventor for a rail 430 to exist on the exterior of said screen 400 and a groove to exist within the body of the shale shaker deck 420 creating a combination where said protrusion may be present exteriorly on the said shaker screen 400 and an accepting channel may exist on the interior of a shale shaker basket (not shown). Moreover, a rail (existing on the exterior of a shaker screen 400 or interior of a shaker deck 420) may exist on the side of a shaker screen or, alternatively, on the top of a shaker screen. This may be accomplished by (a) inserting a protruding portion (e.g., a rail) exhibited along each side, top or bottom length of a shaker screen into an accepting channel on the inner portion of the shale shaker basket running the length of the baskets right and left side edges or, alternatively, by (b) inserting a shaker screen into the interior of a shaker basket whereby said basket interior exhibits protruding rails within said right and left receiving sides, bottom or top and said screen exhibits a reciprocal receiving channel or groove for accepting said protruding rail (as shown as screen bottom channel and deck top rail in FIGS. 4-8). Succinctly, male (protrusion) and female accepting (groove) parts may be either (1) male protrusion-exhibiting basket and female (male-protrusion receiving) screen, (2) female (male protrusion receiving) basket and male protrusion-exhibiting screen or a combination thereof wherein the left side of a screen may exhibit “male-basket, female screen” and the right side may exhibit “female-basket, male-screen” or vice versa. Such a protrusion and accepting channel combination may be integrated, manufactured, pinned, welded, bolted, and/or fastened to the basket interior (e.g., bottom, top, or side) upon original construction or via a retrofit where it is contemplated that an accepting (reciprocating) channel or groove (female-type channel) may run along the inner surface of a shale shaker basket (where a shale shaker screen exhibits a male/protruded portion for mating to said basket channel). What is more, a wedge or pneumatic bladder 480 may be utilized to further depress a properly aligned and inserted screen thereby decreasing the space between screen and basket and acting to secure said screen in place. This is accomplished within the present disclosure whereby an inflatable bladder 480 exists opposite the rail and channel system in FIG. 4 thereby acting to “depress” the inserted screen 400 downward wherein a seal is forcibly created via downward pressure but may be accomplished through alternate embodiments.

However, the incorporation of a hydraulic or pneumatic system and functional bladder 480, superior to a shaker screen 400 (See specifically FIGS. 4 and 8), where the present invention is positioned inferiorly, allows pressure to be applied to the top of said shaker screen 400 which acts to secure screen 400 to shaker deck 420 with application of downward, pressure (see the superior placement of said functional bladder 480 in FIGS. 4-8). This inflatable bladder serves the dual function of blocking bypass above an inserted shaker screen 400 and creating a pressurized “seal” between screen 400 and shaker deck 420 inferiorly. The alternative, inferior bladder 480 placement and superior rail and channel system, may also be accomplished so long as the application of pressure exists opposite of the rail and channel system that is the present invention.

More specific to another embodiment of construction, and in addition to a square rail 430 and reciprocating channel 450, a basket deck 420 could be designed or retrofitted to display a cylindrical “male” protrusion 530 (e.g., a cylinder shape) running the inner length of a basket deck’s interior which is made to be inserted into a “C”-shaped channel 550 (e.g., a hollowed half or ³ /4, open-ended cylinder) on a shaker screen 400. As described above this may be also accomplished via a “C”-shaped channel exhibited on the interior length of said shaker basket (deck) and wherein said shaker screen may exhibit a protrusion which is cylinder shaped (not shown). Yet, it is in the contemplation of inventors to have a basket and shaker combination wherein male protrusions and female accepting channels may exist in opposite conformations on either side (i.e., male-basket/ female-screen left and male-screen/female-basket right). It is also contemplated by inventors that the male shape, residing on either the basket interior or screen edge may be of one of various protrusion and accepting, reciprocating shapes including: the aforementioned “square” and cylindrical shapes, FIGS. 4 and 5, respectively, a “star” shape (exhibiting a “star-shaped” protrusion 630 and reciprocating receiving channel 650 in FIG. 6), a hexagonal shape (exhibiting a hexagonal protrusion 730 and reciprocating receiving channel 750 in FIG. 7), a “cross” shape and reciprocating channel, a multi-angular shape and reciprocating channel and/or any other rounded or angular shape “male” capable of communicating with a reciprocal “female” and reciprocating shape. Ultimately, though, the basket and screen are mated as to provide securement, stability and, most importantly, disallowing of fluid to pass (bypass) between basket and screen during high oscillations, maximum flow and peak vibrations regardless of corresponding and reciprocating pairs.

Specific to the present system’s functional bladder 480, in FIGS. 4, 8-9, the bladder itself is an elastomeric, elongated strip having one to a plurality of insertion points (i.e., buttons or seals 830) residing on its superior, top side. The bladder 480 is actuatable by fluid insertion after screen 400 insertion and alignment via the present rail and channel system. The bladder 480 is sealed as to maintain inserted fluid and is made to run the length of a screen’s edge as to provide uniform pressure along the length of a screen’s edge and to provide a continuous barrier to solids and fluid bypass. Conversely, individual bladders may be placed at certain designated points above a shaker screen 400, below a shaker screen, on the sides of shaker screen or a combination thereof (not shown). Further said bladder may be supplied by a hydraulic or pneumatic fluid (ex. a gas or fluid) that is supplied externally to said bladder 480 and may be applied and reapplied or provided under a constant pressure. This is accomplished through fluid insertion, post screen placement, which may be deflated, removed or released for screen 400 adjustment, removal and replacement. The cutaway view of FIG. 8 provides an insertion point 810, through said upper deck rail 720 and into a protruding “button” or seal 830, mating to the superior portion of the surface said bladder 480. Other insertion points may exist and may be employed without loss of functionality. Too, the overall length of said bladder 480 is adjustable to accommodate the side length of a shale shaker screen, the depth is modifiable to accommodate various distances between decks upper and lower edges and thicknesses in relation to inserted fluid and various pressures.

In operation, as illustrated in FIG. 4, bladder 480 acts as an inflatable “wedge” whereby the C-shaped deck bracket 490, running coplanar and parallel to screen 400, accepts screen 400 insertion within said bracket 490 interior, sliding along rail 430 until completely inserted. Thereafter, as depicted in FIGS. 4 and 8, bladder 480 is expanded, through insertion of air or other fluid, and screen 400 is compressed (i.e., depressed downward upon deck flat 420) and a seal is created between (a) the inferior surface 495 of upper arm 490A of deck bracket 490 and the superior surface 480A of bladder 480, (b) the inferior surface 480B of bladder 480 and the superior surface 400A of screen 400, and (c) the inferior surface 400B of screen 400 and the superior surface 420A of deck 420.

In one embodiment, the screen that makes up the present invention may exhibit an indention, channel or “cut out” on the bottom of the screen frame, top of the screen frame or side of a screen frame so long as said channel is mated to a reciprocating protrusion in the basket railing. Where the opposite is true, and a protrusion exists on a screen, that protrusion may exist on the bottom, top or side of said screen and a receiving channel may be positioned to mirror the protrusion. For example, a protrusion existing on the bottom of a screen will mate with a channel of a shaker basket similarly inferiorly placed. Ultimately, though, this designation is mutable so long as when the basket interior and screen exterior are mated together, corresponding and reciprocal segments (components) mate and each fit tightly and securely together with limited to no space existing between the two. Additionally, a wedge, pneumatic air bag or other tension device may be as well used thereby creating pressure and pushing down (up or in) on the screen to create a more secure placement, an even tighter seal or a combination thereof.

In another embodiment, those ends or sides not exhibiting an inflatable bladder may exhibit additional barriers, in the form of elastomeric seals, gaskets, bumpers, blades, fins or other fluid blocking obstacles to fluid bypass or fluid seepage. In yet another embodiment, the above detailed barriers may be positioned on the screen sides or adjacent to protrusions or channels as to further block and obfuscate passageways for fluid seepage and fluid bypass.

Ultimately, by decreasing the distance between the shale shaker screen and basket interior, wear upon the functional shaker basket system components is decreased, the present invention thereby acts by securing screen to basket and decreasing wear, simultaneously, on shaker screens and shaker baskets resulting in the extended longevity of each component. The two-part rail and channel system that is the present invention is designed and implemented in such a way as to allow for the shaker basket and shaker screen to create a contiguous barrier between the functioning parts of the basket assemblage which block seepage, avoids friction and uniformly absorbs vibration. The screen and basket rail and channel system remains firmly fastened to the interior of a shale shaker basket, semi-permanently, having the capability to be easily placed and replaced into the basket of the shale shaker which can be maintained in a secure conformation and alignment until such time as removal becomes desired or, eventually, a necessity. The semi-permanent, secured placement or “locking” of a shaker screen within the interior of a shale shaker basket is capable of withstanding tension, angling and vibratory motions exerted on shaker baskets frames and screens greatly in excess of present implementations and systems. Traditional basket and screen combinations do not exhibit the same capacity for strict alignment, secured placement and limited separation distances.

These particular embodiments disclosed are merely illustrative, which may be apparent to those having skill in the art that may be modified in diverse but equivalent manners. It is therefore contemplated that these particular embodiments may be altered and modified and that all such alterations are considered within the scope and spirit of the present application. And while these illustrations are of a limited number set, it is clear that the invention itself is mutable to any number of arrangements, configurations and modifications without departing from the invention’s spirit thereof.