Patent Publication Number: US-2020291732-A1

Title: Filtration System for Use in a Shale Shaker

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     None 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     None 
     FIELD OF THE INVENTION 
     The invention generally relates to a system for use in a shale shaker, and more specifically the system is used for filtering solid matter from drilling fluids. 
     BACKGROUND OF THE INVENTION 
     Drilling operations are common across the oil and gas, construction, and mining industries. For the oil and gas industry, whether onshore or offshore, drilling is considered one of the first steps in the process of extracting hydrocarbon-based resources. In the drilling process, a hole is bored in the earth with a drilling rig by rotating a drill bit attached to a drill string. Drilled rocks, sand, and metals etc., known generally as cuttings or solids, reduce drilling speed and increase drilling cost. Accordingly, drilling fluid(s), also known as “mud,” is circulated from the rig surface to the bottom of the wellbore (“hole”), proximate the drill bit, to remove the cuttings. Cuttings are transported from the bottom of the hole to the surface, where, typically, a series of devices known as shale shakers are used to filter the cuttings from the valuable drilling fluid. The filtered mud is collected and pumped downhole for reuse, forming a closed-loop drilling fluid system throughout the drilling process. 
     Generally, the screening devices are referred to as shale “shakers” because vibrational motion (i.e., “shaking”) of the apparatuses is utilized to assist in the filtration process. Shale shakers are very important in the drilling process because they are the first line of defense against solids contamination, as solids bypassing the shale shakers can cause significant operational costs. In addition to the cost of having to filter the same solids more than once, increased chemical consumption, fluid dilution, reduced drilling speed, and damaged equipment are additional effects of solids contamination in mud. 
     Generally, in a shale shaker a plurality of filter screen components are aligned adjacent to each other within a shaker bed to filter cuttings from the mud. The filter screen components are mainly the mesh and frame, whereby one or more mesh layers are employed to prevent solids above a certain diameter from passing through. This maximum particle size that a given shaker screen will allow to pass there through is known as the filtration “cut point.” The screen mesh layer(s) act as a sieving mechanism while the frame provides structural integrity to the mesh while it operates under vigorous vibration, temperature, and load. 
     Although shale shakers have long been used in drilling operations, it is difficult to replace the filter screens in the shale shakers, and life of the filter screens is short. The replacement of the filter screens in shale shakers normally requires delaying or even halting the drilling operations, where workers have to unlock the present filter screens and remove them from the shaker bed, insert new filter screens, and lock them in place before restarting the shale shakers to resume drilling operations. In some shaker models, filter screens are horizontally aligned next to each other. Accordingly, if the damaged filter screen that has to be removed and replaced is positioned on an inner part of the shale shaker, all of the other filter screens that are arranged in line outside it will have to be removed first in order to get to the damaged filter screen out. In addition, due to the weight and bulkiness of the screens, the replacement process is considered tedious and wastes valuable drilling time. Moreover, since vigorous vibration is applied to the screens during the filtration process, friction between cuttings and screens will eventually wear the mesh down, and abrasions, tears, and punctures of the screens are common. 
     Routine visual inspections are conducted to try to identify these defects. It is often difficult for workers to visually identify damaged filter screens since they are constantly covered by mud and cuttings while shakers are operating. Frequently, screen damage is only identified many hours or even days after defects arise, and high volumes of solids bigger than the cut point have passed through without being filtered. Since there is no preventive solution to solids bypass available today, screen replacement is necessarily conducted after the fact and the impact of solids contamination is absorbed each time a screen is damaged. 
     Once a damaged screen is identified and removed, it is common for workers to patch the hole(s) in order to continue using the filter screen longer. However, as the patch replaces an area of filtration with a non-sieve surface, every time a repair is conducted, the effective screen area is reduced along with its efficiency in processing mud. Accordingly, after several repairs, the entire filter screen is typically replaced with a brand new screen. The damaged screen will be discarded, even though a large fraction of the screen area is still in pristine condition. This approach is very wasteful. 
     Since oil rigs commonly operate in remote locations, logistics can pose a major challenge to operations. It is time consuming and costly to transport shaker screens to the drilling sites, especially to offshore facilities. In one aspect, filter screen manufacturers normally pack their screens in a box and transport them to the nearest supply warehouse, usually near a jetty, before shipping them out to the end users offshore. At the oil rigs, screens that were packed in boxes have to be hand-carried to the site location where the shale shakers are positioned. The transport process can involves many transfers using cranes and forklifts. Not only does this result in high logistics costs, it is also common for the filter screens to arrive having been damaged in transit. 
     With regard to the prior art in this field, disclosed in United Kingdom Patent No. GB 2245191 to Bailey et al. is a filter screen assembly having a plurality of modular screen units. With the use of the filter screen assembly described therein, only the damaged screen need be changed and replaced, instead of having to replace the entire filter screen. The patent further discloses that each modular screen unit has a snap engagement means allowing the screen unit to be fitted accordingly. While this patent teaches a simplified process for filter screen replacement, the invention does not provide for convenient removal the screen unit from the shale shaker. Instead, the invention requires that the user has to cut around the periphery of the screen unit before placing a new screen unit into the slot. As would be understood by one skilled in the art, considering the strength and precision required to cut a screen, it is believed that to employ the device of Bailey et al. the entire filter screen would have to be removed from the shaker bed prior to work. Furthermore, additional tools would have to be used to cut the screen unit away from the assembly, and it would be difficult to ensure that the damaged screen unit is cut correctly without damaging any of its neighboring units, not to mention the risk of injury in handling prickly steel mesh. 
     U.S. Pat. No. 9,180,493 to Dahl also discloses a shaker screen filter for a drilling fluid shaker. Similar to GB 224519, the Dahl patent similarly provides modular units of filter screens that can be replaced when screen damage occurs. Specifically, this patent discloses a filtration system that provides a plurality of cell plug filters, wherein each filter comprises an engagement mechanism arranged for locking the cell plug filters onto the main frame. Importantly, the patent application discloses the use of a screw mechanism to lock and release the filter from the main frame. It is believed that such replacement process would require a special tool to operate the screw mechanism. Further, the technology disclosed in the Dahl patent also is necessarily heavy and quite wasteful, because the entire screw mechanism has to be discarded along with the screen when damage occurs. 
     U.S. Pat. No.  9 , 744 , 564  to Cady discloses an apparatus relating to a vibratory separator screen utilizing a multiple screen design, where the apparatus comprises a plurality of modular inserts wherein mesh screen surfaces are stacked on a screen frame. While this patent provides modularity, it does not provide any greater level of convenience of screen replacement than Bailey et al. or Dahl above. As the invention is disclosed in Cady, the entire screen has to be removed from the shaker bed in order to remove the damaged insert, as they can only be slid out from the sides. Further, there is no disclosure of any element that prevent the bypass of solids through the connections between the screens. 
     Thus, despite the disclosure of modular filter screens in the prior art, no convenient and useful modular solution exists in the field, which why in the market currently the repair method of choice still requires blinding the damaged location, either with a snap-able plug or silicone putty. Both patching means reduce the screening surface and the filtration efficiency. After a few patching repairs, the entire screen must be replaced to maintain trade-off between screen life and filtration efficiency. 
     BRIEF SUMMARY OF THE INVENTION 
     Embodiments of a filtration system for use in a shale shaker generally comprise a frame with a plurality of sub-divided openings, and a plurality of screen apparatuses, each comprising a filtration component reversibly coupled to a positioning component, wherein the screen apparatuses are adapted and configured for placement into the frame openings, wherein each filtration component comprises a screen which comprises a one or more mesh layers, and wherein a first connecting member reversibly secures the filtration component in position in relation to the positioning component, and a second connecting member reversibly secures the positioning component in the sub-divided frame opening. In one aspect, the invention provides an apparatus for use in a shale shaker and a filtration method that allows for the filtration component to be installed and removed in a simplified manner. 
     Embodiments of the invention also provide an apparatus for use in a shale shaker that is configurable to multiple cut points, and provides a preventive solution to solids bypass in the event of screen damage. Additionally, the invention allows workers to readily replace only damaged screens with new non-blanked screens, thereby all keeping in service all existing filter screens that are undamaged. Finally, the invention provides an apparatus for use in a shale shaker that is modular in size and light in weight, where the apparatus can be conveniently packed and shipped, thereby saving time, cost and labor. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention will now be described with reference to the drawings wherein: 
         FIG. 1  illustrates an exploded view of an embodiment of a screen apparatus of the present invention. 
         FIG. 2  illustrates an exploded view of an embodiment of a portion of a filtration system of the present invention. 
         FIG. 3 a    illustrates a perspective view of an embodiment of a positioning component of the present invention. 
         FIG. 3 b    illustrates a top view of the positioning component embodiment depicted in  FIG. 3   a.    
         FIG. 3 c    illustrates a bottom view of the positioning component embodiment depicted in  FIG. 3   a.    
         FIG. 3 d    illustrates a side view of an embodiment of a positioning component of the present invention. 
         FIG. 4 a    illustrates a perspective view of an embodiment of a filtration component of the present invention. 
         FIG. 4 b    illustrates a bottom view of the filtration component embodiment depicted in  FIG. 4   a.    
         FIG. 5 a    illustrates an embodiment of a filtration component of the present invention comprising one screen unit. 
         FIG. 5 b    illustrates an embodiment of a filtration component of the present invention comprising two screen units. 
         FIG. 5 c    illustrates an embodiment of a filtration component of the present invention comprising three screen units. 
         FIG. 6  illustrates an exploded view of an embodiment of a filtration component of the present invention comprising three screen units. 
         FIG. 7 a    illustrates a perspective, partial cross-sectional view of an embodiment of an installed screen apparatus of the present invention. 
         FIG. 7 b    illustrates a side, partial cross-sectional view of an embodiment of an installed screen apparatus of the present invention. 
         FIGS. 8 a , 8 b , and 8 c    illustrate a schematic representation of solids being filtered by embodiments of a filtration component of the present invention comprising one, two, and three mesh layers, respectively. 
         FIGS. 9 a , 9 b , 9 c , 9 d , and 9 e    illustrate embodiments of a filtration component of the present invention comprising various mesh to filtration component attachment configurations. 
         FIG. 10 a    illustrates an embodiment of a positioning component of the present invention engaged with an embodiment of a filtration component of the present invention. 
         FIG. 10 b    illustrates an embodiment of a positioning component of the present invention positioned within an embodiment of a frame opening of the present invention and engaged with an embodiment of a filtration component of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION 
     The following description is presented to enable a person of ordinary skill in the art to make and use the various embodiments. Descriptions of specific devices, techniques, and applications are merely exemplary. Various modifications to the embodiments described herein will be readily apparent to those of ordinary skill in the art, and the general principals defined herein may be applied to other examples and applications without departing from the scope of the various embodiments. As used herein, directional indication terms such as, but not limited to, top, bottom, up, upward, upper, down, downward, lower, and like are for descriptive reference only as embodiments of components of the invention are configurable able in various orientations. 
       FIG. 1  illustrates an exploded view of an embodiment of a screen apparatus  1  of the present invention. In one embodiment, screen apparatus  1  comprises one or more filtration components  2  and a positioning component  3 , and optionally, one or more first sealing devices  51  and/or second sealing devices  52 . In one embodiment, a screen apparatus  1  is positionable within an opening  4  of a frame unit  6  of a frame  5 , as depicted in  FIG. 2 . 
     In one embodiment, a first sealing device  51  is positionable at least partially within an upper groove  53   a  of a bottom surface  9  of filtration component  2  (visible in  FIG. 4 b   ) and a lower groove  53   b  of a top surface  10  of positioning component  3  (shown in  FIG. 3 a   ) when filtration component  2  is engaged with positioning component  3 , as visible in  FIG. 7 a   . In other embodiments (not shown), a first sealing device  51  may be utilized in a screen apparatus  1  comprising only an upper groove  53   a , only a lower groove  53   b , or no groove. In one embodiment, a first sealing device  51  (and/or a second sealing device  52 , discussed in detail below), may comprise an O-ring (also known as a toric joint), washer, or gasket, that may comprise an elastomeric (rubber) material, natural or synthetic. In one embodiment, a first sealing device  51  comprises nitrile rubber. 
     Referring again to  FIG. 1 , and also to  FIG. 2 , in one embodiment positioning component  3  is sized so that it may be snugly placed at least partially within an opening  4  of a frame unit  6 , although the invention is not so limited and other configurations are contemplated. In one embodiment, filtration component  2  comprises width and length dimensions substantially similar to the width and length dimensions of positioning component  3 ; i.e., the two components are of substantially the same length and width. In other embodiments (not shown), a filtration component  2  may comprise width and/or length dimension less than that of the positioning component  3 , such that a plurality of filtration components  2  may be positioned in cooperation with a positioning component  3 . In one embodiment, filtration component  2  and positioning component  3  are adapted and configured to be cooperatively engaged with each other, as described below. 
     In one embodiment, a second sealing device  52  is positionable circumferentially about a bottom surface  11  of positioning component  3 , as shown in  FIG. 3 c   . In one embodiment (not shown), a bottom surface  11  of positioning component  3  comprises an upper groove (not shown) wherein a second sealing device  52  is positionable at least partially there within. In one embodiment, when positioning component  3  is engaged with frame  5  opening  4 , second sealing device  52  is disposed between positioning component  3  and an upper surface  8  of frame  5 , as shown in  FIGS. 7 a  and 7 b   . In other embodiments (not shown) sealing device  52  may be disposed between positioning component  3  and another surface of frame  5 . In other embodiments (not shown) a second sealing device  52  may be positioned elsewhere within a screen apparatus  1 . 
       FIG. 2  depicts an embodiment of a modular filtration system  7  of the present invention, wherein only a single module (comprising a screen apparatus  1  in cooperation with a frame unit  6  opening  4 ) is shown. In one embodiment, frame  5  is subdivided into a plurality of units  6 , each unit  6  comprising an opening  4  segregated from other openings  4  by portions of frame  5 . In one embodiment, units  6  of a frame (and therefore, screen apparatuses  1 ) may be substantially rectangular in shape, as depicted  FIG. 2 , although the invention is not so limited and other shapes may be employed. In addition, units  6  of a frame  5  may all comprise the same shape or may be of different shapes. In one embodiment frame  5  comprises a metal material, such as, but not limited to, stainless steel, and/or a synthetic material, such as, but not limited to, plastic. In one embodiment (not shown), a filtration system  7  comprises a frame  5  having its plurality of frame units  6  equipped with such a module. As would be understood by one skilled in the art, a filtration system  7  may be employed in a standard shale shaker to filter drilling fluid solids. 
     In various embodiments, as indicated in  FIGS. 1 and 2 , and depicted in more detail in  FIGS. 4 a , 4 b   , and  6 , filtration component  2  comprises a screen frame  16  comprising one or more screens  21  each comprising a support structure  23 . In one embodiment, each screen  21  comprises one more layers of a sieving material such as, but not limited to, a woven mesh, draped across the support structure  23 . In other embodiments (not shown), the sieving material may comprise holes (orifices), slits, and/or other openings adapted and configured to filter solid particles from a liquid stream. In one embodiment the woven mesh comprises metal wire, but other materials may be employed. In one embodiment, a mesh comprises aperture openings (not separately labeled) of from about 20 μm to about 4,000 μm, although the invention is not so limited and other aperture opening sizes may be employed. 
     In one embodiment, mesh  22  is connectively attached about a periphery thereof to an upper surface of support structure  23  (not separately labeled) proximate its periphery. In one embodiment, such connection comprises fusing mesh  22  to the periphery of upper surface of support structure  23  using a heat press, although other methods may be employed. In one embodiment, any excess mesh (not shown) is trimmed off each screen  21  and screen frame  16  is applied over screen(s)  21  to provide a filtration component  2 . 
       FIG. 3 a    is a perspective view of an embodiment of a positioning component  3  of the present invention, wherein a support structure  25  thereof comprises intersecting support beams  26 . In one embodiment, gaps (openings)  29  between support beams  26  are provided for fluid flow through the positioning component  3 . In one embodiment, the geometry of positioning component  3  support structure  25  is substantially identical to that of filtration component  2  support structure  23  (discussed below), but the invention is not so limited and geometries of positioning component  3  support structure  25  different than that of the filtration component  2  support structure  23  may be employed. In one embodiment, positioning component  3  may comprise a thermoplastic material, although any suitable material such as, but not limited to, metal or other polymeric materials may be employed, as would be understood by one skilled in the art. 
       FIG. 3 a    depicts an embodiment of positioning component  3  comprising one or more first connecting members  31 , which are adapted and configured to engage corresponding apertures  12  of filtration component  2  bottom surface  9 . In one embodiment, positioning component  3  comprises four first connecting members  31 . In one embodiment, first connecting members  31  extend upward from top surface  10  of positioning component  3 . In one embodiment, connecting members  31  are disposed proximate one or more of the corners  13  of positioning component  3 . In one embodiment, corresponding apertures  12  are disposed proximate one or more of the corners  14  of screen frame  16  (see  FIG. 4 a   ). 
     In one embodiment, a positioning component  3  may comprise one or more second connecting members  32  positioned about the periphery thereof. In one embodiment, positioning component  3  comprises four second connecting members  32 . In one embodiment, second connecting members  32  are disposed proximate bottom surface  11  of positioning component  3 . In one aspect, connecting members  32  are adapted and configured to reversibly attach positioning component  3  to frame  5 . In one embodiment, a connecting member  32  comprises a retention clip comprising a beveled surface and extending slightly outward with respect to the center of positioning component  3  (not separately labeled), such that when the bottom surface  11  of positioning component  3  is positioned (within a frame  5  unit  6 ) against upper surface  8  of frame  5 , the second connecting members  32  are biased slightly inward and upon advancement of a locking surface thereof below frame  5  the second connecting members  32  “click” into an engaged arrangement with frame  5 , thereby creating an attachment of positioning component  3  to frame  5  (see  FIG. 7 b   ). In one embodiment, connecting members  32  possess enough flexibility that their engagement with frame  5  can be reversed by applying a nominal inward force to connecting members  32  to disengage them from frame  5 . 
     In one aspect, the number as well as the relative positioning of the first connecting members  31  and second connecting members  32  are design variables based in part on the overall size and structure of the positioning components  3 , filtration components  2 , and frame  5 , as would be understood by one skilled in the art. 
     In the embodiment of  FIG. 3 a   , lower groove  53   b , disposed on top surface  10  of positioning component  3 , can be more clearly seen. In one embodiment, lower groove  53   b  extends circumferentially proximate the exterior edges of positioning component  3 . 
     In one embodiment, first connecting members  31  extend slightly outward with respect to a center of positioning component  3  (not separately labeled), such that when an top surface  10  of a positioning component  3  is positioned against a bottom surface  9  of a filtration component  2  (in an orientation as depicted in  FIGS. 1 and 3 ), the first connecting members  31  are biased slightly inward and upon introduction of engagement members  33  thereof into the corresponding apertures  12  the first connecting members  31  “click” into an engaged arrangement with orifices  15  of the apertures  12 , thereby creating an attachment of filtration component  2  to positioning component  3 . In one embodiment, connecting members  31  possess enough flexibility that their engagement with the orifices  15  can be reversed by applying a nominal force to engagement members  33  (e.g., with a screwdriver or other hand implement). In one embodiment, such displacement force may be applied through the orifice  15 . 
       FIG. 3 b    depicts a top view of an embodiment of a positioning component  3  of the present invention, showing top surface  10  thereof.  FIG. 3 c    depicts a bottom view of an embodiment of a positioning component  3  of the present invention, showing bottom surface  11  thereof. In the embodiment of  FIG. 3 c   , a second sealing device  52  is circumferentially disposed on bottom surface  11  of positioning component  3 . In one aspect, second sealing device  52  may be so disposed when positioning component  3  is positioned into engagement with a frame  5  unit  6 , as depicted in  FIGS. 7 a  and 7 b   . In one embodiment, a portion of positioning component  3  extends downward into unit  5  opening  4  when positioning component  3  is positioned into engagement with a frame  5  unit  6 . In one embodiment, as shown in  FIG. 3 d   , second connecting members  32  extends downward below bottom surface  11  of positioning component  3 . 
       FIG. 4 a    shows a perspective view of an embodiment of a filtration component  2  of the present invention, and  FIG. 4 b    shows a bottom view of an embodiment of a filtration component  2  of the present invention. In the embodiments depicted in  FIGS. 4 a  and 4 b   , a filtration component  2  comprises a support structure  23  comprising a grid of intersecting support beams  24 . In one embodiment, gaps (openings)  29  between support beams  24  are provided for fluid flow through the filtration component  2 . In one aspect, the desired dimensions and configuration of support structure  23  are determined in view of the need to provide adequate support to the mesh during filtration to prevent mesh damage, but to also provide maximization of areas flow areas between the support beams  24 . Embodiments comprising different support structure  24  geometries are discuss below with respect to  FIGS. 9 a   - 9   e.  In one embodiment, filtration component  2  may comprise a thermoplastic material, although any suitable material such as, but not limited to, metal or other polymeric materials may be employed, as would be understood by one skilled in the art. 
     As shown in the embodiment of  FIG. 4 a   , a screen frame  16  may comprise, at one or more corners  14  thereof, one or more orifices  15 . In the embodiment of  FIG. 4 b    can be seen one or more apertures  12  on bottom surface  9  of screen frame  16  proximate corners  14  thereof. As described above, apertures  12  are adapted and configured to accommodate first connecting members  31  to provide connection of filtration component  2  and positioning component  3 . The embodiment of  FIG. 4 b    also shows an upper groove  53   a  in a bottom surface  9  of filtration component  2 . 
       FIGS. 5 a , 5 b , and 5 c    depict (in cross-sectional side view) embodiments of filtration components  2  of the present invention comprising one, two, and three screens  21 , respectively. In one embodiment, each mesh item  22  depicted in  FIGS. 5 a , 5 b , and 5 c    may comprise a single mesh  22  layer or a plurality of mesh  22  layers, as would be understood by one skilled in the art. As shown in  FIGS. 5 b  and 5 c   , multiple screens  21  may be stacked within a filtration component  2 . In one aspect, when a plurality of identical mesh  22  layers are provided in a screen  21 , and the mesh  22  layers are arranged such that the mesh openings line up vertically, the screen  21  comprises a cut point equal to the opening size of the mesh  22  there within. In another aspect, when a plurality of identical mesh  22  layers are provided in a screen  21 , and the mesh  22  layers are arranged such that the mesh openings are staggered (i.e., do not line up vertically), or different meshes  22  (i.e., meshes  22  having different mesh opening sizes) are layered and provided in the screen  21 , the cut point of the screen can be less than the smallest opening size of the meshes  22  there within. In one embodiment, a filtration component  2  may comprise a plurality of screens  21  having the same or different cut points. Although the embodiments shown encompass three or fewer screens  21 , the invention is not so limited and a greater number of screens  21  may be employed in a filtration component  2 . In one embodiment, screen(s)  21  is/are secured within a screen frame  16  by a process such as ultrasonic welding, although the invention is not so limited and other affixation means and methods may be employed. 
     In one embodiment, screen(s)  21  disposed within a filtration component  2  may be permanently installed there within; i.e., when a filtration component  2  is taken out of service, it would need to be replaced by a new filtration component  2 , however, the invention is not so limited and in other embodiments, individual screens  21  may be removably positioned within a filtration component  2  such that the filtration component  2  can be disengaged from a positioning component  3  and the screen(s) may be individually replaced, whereby the filtration component  2  containing one or more new screens  21  may be re-engaged with the positioning component  3 . In this aspect, portions of a filtration component  2  may be re-used when one or more replacement screens are employed. An exploded view of an embodiment of a filtration component  2  comprising three screens  21  is shown in  FIG. 6 . 
     Referring now to  FIG. 7 a   , shown is a perspective cross-sectional view of an embodiment of a portion of a filtration system  7  of the present invention; i.e., a filtration component  2  engaged with a positioning component  3  that is situated in a frame  5  opening  4  is depicted. In this embodiment, three stacked screens  21  are disposed within filtration component  2 , filtration component  2  is engaged with positioning component  3 , and positioning component  3  is disposed partially within and engaged with frame  5  opening  4 . Also visible in  FIG. 7 a    is a first sealing device  51  sandwiched between bottom surface  9  of filtration component  2  and a top surface  10  of positioning component  3 , and a second sealing device  52  sandwiched between bottom surface  11  of positioning component  3  and upper surface  8  of frame  5 . In one aspect, the first sealing device  51  and second sealing device  52  are employed to prevent fluid and solids from bypassing the desired sieving fluid flow pathway between the positioning component  3 , filtration component  2 , and opening. 4  of a frame  5  unit  6 . 
       FIG. 7 b    depicts a side cross-sectional view of an embodiment of the filtration system  7  module shown in  FIG. 7 a   . In  FIG. 7 b   , the engagement of second connecting member  32  with frame  5  can be seen. First sealing device  51  and second sealing device  52  are also visible in  FIG. 7   b.    
     Referring now to  FIGS. 8 a , 8 b , and 8 c   , a schematic representation of solids being filtered by embodiments of a filtration component  2  of the present invention comprising one, two, and three screens  21 , respectively, are shown. For ease of viewing, screen frames  16  are omitted from the depictions of the filtration components  2  in  FIGS. 8 a , 8 b , and 8 c   . In the embodiment of  FIG. 8 a   , the single screen  21   a  provides one or more mesh layers  22   a  having a cut point such that large diameter solid particles  41  in a fluid stream (not shown) are filtered by the mesh  22   a , while medium diameter solid particles  42  and small diameter solid particles  43  pass through screen  21   a . In the embodiment of  FIG. 8 b   , the filtration component  2  comprises two screens  21   a  and  21   b , whereby medium diameter solid particles  42  that pass through screen  21   a  are filtered by screen  21   b  mesh layer(s)  22   b  (having a smaller cut point than mesh layer(s)  22   a ), and small diameter solid particles  43  pass through screen  21   b . In the embodiment of  FIG. 8 c   , the filtration component  2  comprises three screens  21   a ,  21   b , and  21   c , whereby small diameter solid particles  43  that pass through screens  21   a  and  21   b  are filtered by screen  21   c  mesh layer(s)  22   c  (having a cut point small than mesh layer(s)  22   b ). In other embodiments (not shown), the number, absolute and relative mesh opening (cut point), and arrangement of a plurality of screens  21  in a filtration component  2  may be varied to accomplish desired filtration efficiency, as would be understood by one skilled in the art. In addition, in a screen  21  comprising a plurality of mesh layers  22 , the mesh layers  22  therein may comprise the same or different cut point. 
     In one aspect, as filtration components  2  are designed to be easily replaced as necessary, and filtration components  2  may have different cut points, it would be useful to have method of readily identifying the cut point of a filtration component  2  so that when replacement is warranted, a worker could easily select the appropriate replacement filtration component  2  from a storage location. In one embodiment, filtration components  2  of the present invention are visually distinguishable by, for example, color. In this aspect, a color coding of filtration components  2  allows for the fast and reliable selection of replacement filtration components  2 . In other embodiments, other identifiers could be employed, as would be understood by one skilled in the art. 
     In one aspect, a plurality of screens  21  may be employed to provide a backup filtration component that functions only to ensure filtering of solids when screen damage has occurred. In one embodiment, for example, a filtration component  2  of the present invention may comprise three screens  21 , wherein the top screen  21  mesh  22  comprises aperture openings having a diameter “D,” the middle screen  21  mesh  22  comprises aperture openings having a smaller diameter “½ D,” and the bottom screen  21  mesh  22  comprises aperture openings having a diameter “D.” In this example, under normal operations (i.e., when the top and middle screens  21  are functioning as desired), only particles having a diameter of less than ½ D encounter the bottom screen  21 , and so the bottom screen  21  does not perform a filtering function. When, for example, the top screen  21  and the middle screen  21  are damaged such that one or more openings in the meshes  22  thereof are of a size greater than D, the bottom screen  21  mesh  22  functions to prevent solid particles having a diameter greater than D from getting past the filtration system  7 . This configuration of screens  21  is merely exemplary, and other configurations may be utilized, as would be understood by one skilled in the art. 
     Although the meshes  22  shown in  FIGS. 8 a -8 c    are depicted as substantially planar (i.e., two dimensional), the invention is not so limited and three dimensional surface geometries may be employed. In one embodiment (not shown), screens  21  may comprise three dimensional (e.g., “wavy”) meshes  22  and/or protuberances on the surface of a mesh  22 . These protuberances may be regular in shape, e.g., pyramids, cones, etc., and/or irregular/random in shape, and may be evenly or unevenly spaced apart. 
     Referring now to  FIGS. 9 a   - 9   e,  embodiments of screens  21  are depicted in which the shape of the support structure  23 , and/or the connectivity thereof to the mesh  22 , are varied. In the embodiment of  FIGS. 9 a , 9 b , 9 c , and 9 d   , the support structure comprises substantially perpendicularly oriented support beams  24 . In the embodiment of  FIG. 9 a   , mesh-support contacts  27  indicate the areas where the mesh  22  is affixed to the support structure  23 . In the  FIG. 9 a    embodiment, the affixing contact between mesh  22  and the support structure  23  is limited to points of contact at the intersections of support beams  24 . In  FIGS. 9 b   - 9   d,  the affixing contact between mesh  22  and the support structure  23  comprises points of contact (as in  FIG. 9 a   ), as well as lines of contact along one or more support beams  24 . In the embodiment of  FIG. 9 e   , the support structure  23  comprises hexagonally shaped support beams  24  arranged in a honeycomb-like pattern. As one skilled in the art would appreciate, the relative sizes, shapes, and configuration of support structure  23  beams  24 , as well as the configuration of mesh-support contacts  27  may be varied to suit individual robustness and filtration efficiency requirements. 
       FIG. 10 a    depicts additional embodiments of a filtration component  2  and a positioning component  3  of the present invention. As shown in the embodiment of  FIG. 10 a   , positioning component  3  first connecting members  31  comprise a retention clip comprising a beveled surface and are oriented upwardly and inwardly proximate corners  13  of positioning component  3 . In complementary fashion, the corners  14  of the screen frame  16  embodiment shown in  FIG. 10 a    are cut away and comprise an engagement member  60  , such that when a top surface  10  of the positioning component  3  is positioned against the bottom surface  9  of the filtration component  2  (in an orientation as depicted in  FIGS. 1 and 3 ), the first connecting members  31  are biased slightly outward and upon advancement thereof beyond an edge  61  of engagement members  60 , the first connecting members  31  “click” into an engaged arrangement with engagement members  60 , thereby creating an attachment of filtration component  2  to positioning component  3 . In one embodiment, connecting members  31  possess enough flexibility that their engagement with the engagement members  60  can be reversed by applying a nominal force to engagement members  33  (e.g., with a screwdriver or other hand implement). 
       FIG. 10 b    depicts further additional embodiments of a filtration component  2  and a positioning component  3  of the present invention as part of a filtration system 7 . As shown in the embodiment of  FIG. 10 b   , the positioning component  3  comprises first connecting members  31  comprising a retention clip comprising that extend upward and comprise one or more engagement members  70  comprising a beveled surface extending perpendicularly outward therefrom. As shown in the embodiment of  FIG. 10 b   , screen frame  16  comprises apertures  71  proximate corners  14  thereof, such that when a top surface  10  of the positioning component  3  is positioned against the bottom surface  9  of the filtration component  2  (in an orientation as depicted in  FIGS. 1 and 3 ), the first connecting members  31  are biased slightly inward and upon advancement thereof beyond an edge  72  of apertures  71 , the first connecting members  31  “click” into an engaged arrangement with apertures  71 , thereby creating an attachment of filtration component  2  to positioning component  3 . In one embodiment, connecting members  31  possess enough flexibility that their engagement with the apertures  71  can be reversed by applying a nominal force to engagement members  70  (e.g., with a screwdriver or other hand implement). 
     Although various embodiments of positioning component  3  first connecting members  31  and devices for utilizing them to reversibly attach positioning component  3  to filtration component  2  are described herein, the invention is not so limited and any suitable reversible attachment mechanism may be employed for this purpose. Similarly, while an embodiment of a positioning component  3  second connecting member  32  is described herein, the invention is not so limited and any suitable reversible attachment mechanism may be employed for the purpose of attaching positioning component  3  to frame  5 . 
     Operation 
     In one embodiment, a filtration system  7  of the present invention is provided by engagingly positioning a screen apparatus  1  into each of a plurality of frame  5  units  6 . In one embodiment, for each unit  6  a positioning component  3  and a second sealing device  52  are centrally positioned above an opening  4 , wherein the second sealing device  52  is circumferentially disposed beneath the bottom surface  11  such that when the positioning component  3  is inserted partially into the opening  4  the second sealing device  52  is sandwiched between bottom surface  11  and the upper surface  8  of frame  5 , whereupon the positioning component  3  is advanced downward into opening  4  until the one or more second positioning members  32  of positioning component  3  advance beneath the frame  5  and “click” into engagement therewith. In one embodiment, a filtration component  2  and a first sealing device  51  are centrally positioned above the installed positioning component  3 , wherein the first sealing device  51  is circumferentially disposed beneath the bottom surface  9  such that when the filtration component  2  bottom surface  9  is abuttingly positioned against positioning component  3  top surface  10  the sealing device  51  device is sandwiched there between whereby the sealing device  51  is partially disposed within upper groove  53   a  and lower groove  53   b , whereupon the first connecting member(s)  31  are advanced into filtration component  2  apertures  12  until the one or more first positioning members  31  are disposed at least partially within the orifice(s)  15  and “click” into engagement therewith. 
     In another embodiment, the order of installation is reversed and the filtration component  2  is first engaged with the positioning component  3 , whereupon the positioning component (with the filtration component coupled thereto) is installed into the frame  5  opening  4 , as described above. 
     To remove a filtration component  2  from an installed screen apparatus  1 , positioning component  3  first connecting member(s)  31  is/are manipulated (e.g., biased inward) to disengage engagement member(s)  33  from filtration component  2  orifice(s)  15 . The filtration component  2  is then displaced from the positioning component  3 . To remove a positioning component  3  from an installed screen apparatus  1 , positioning component  3  second connecting member(s)  32  is/are manipulated (e.g., biased inward) to disengage second connecting member(s)  32  from frame  5 . 
     In another embodiment, the order of removal is reversed and the positioning component  3  is removed from frame  5  unit  6  opening  4  first, and filtration component  2  may be disengaged from positioning component  3  as described above. 
     In one aspect, a filtration system  7  comprising one or more screen apparatuses  1  may be utilized to filter liquids such as, but not limited to, drilling fluids, wherein damage to screen  21  meshes  22  can be addressed by removal of only the affected filtration component  2  (or entire screen apparatus  1 , if desired), whereupon a replacement filtration component  2  is provided to the screen apparatus  1  and fluid filtration can continue. In one aspect, replacement screen(s)  21  may be installed on the removed filtration component  2  for reuse. 
     In one embodiment, a typical drilling fluid filtration operation comprises positioning an embodiment of a filtration system  7  of the present invention on a shaker bed, as would be understood by one skilled in the art. Since a typical shale shaker utilizes a vibratory motor to generate motion to the shaker bed, it is important to ensure that a filtration system employed therewith remains in a functional arrangement during the filtration process and is not displaced by the vibrations. As described herein, the component securement features of a filtration system  7  meet this requirement. 
     Method 
     In one embodiment, a method of utilizing a filtration system  7  of the present invention comprises: 
     A Frame Provision Step comprising providing a frame, such as a frame  5 , comprising a plurality of subdivided units, such as units  6 , with each unit comprising an opening, such as an opening  4 ; 
     A Positioning Component Installation Step comprising providing a plurality of positioning components , such as positioning components  3 , each proximately above a frame unit opening, and inserting at least a portion of a bottom section of each positioning component into the proximate opening such that at least a portion of one or more positioning component second connecting members, such as second connecting members  32 , abuts a bottom surface of the frame, whereby the positioning component is securely, but reversibly, engaged with the frame; 
     A Filtration Component Installation Step comprising providing a plurality of filtration components, such as filtration components  2 , each proximately above an installed positioning component, and lowering each filtration component onto a top surface of an installed positioning component such that at least a portion of each of one or more positioning component first connecting members, such as first connecting members  31 , are provided within a filtration component aperture, such as an aperture  12 , whereby at least a portion of an engagement member of each first connecting member, such as an engagement member  33 , is cooperatively interacts with a filtration component aperture orifice, such as an orifice  15 , whereby the filtration component is securely, but reversibly, engaged with the positioning component; 
     A Filtration Step comprising flowing a particulate containing liquid downward through a top surface of the filtration component that comprises a screen, such as a screen  21 , the screen comprising one or more layers of a mesh, such as mesh  22 , whereby the particulate matter in the liquid is filtered out and the liquid flows through filtration component openings, such as openings  28 , through the positioning component via openings, such as openings  29 , therein, and through the frame unit opening; and 
     (Optionally) A Filtration Component Replacement Step comprising disengaging at least one filtration component from the positioning component with which it is engaged, and installing another filtration component onto the positioning component. 
     The above embodiment of a method of the present invention is merely exemplary, and additional embodiments of a method of utilizing a filtration system  7  of the present invention consistent with the teachings herein may be employed. In addition, in other embodiments, one or more of these steps may be combined, repeated, re-ordered, or deleted, and/or additional steps may be added. 
     While the preferred embodiments of the invention have been described and illustrated, modifications thereof can be made by one skilled in the art without departing from the teachings of the invention. Descriptions of embodiments are exemplary and not limiting. The extent and scope of the invention is set forth in the appended claims and is intended to extend to equivalents thereof. The claims are incorporated into the specification. Disclosure of existing patents, publications, and known art are incorporated herein to the extent required to provide reference details and understanding of the disclosure herein set forth.