Patent Publication Number: US-RE38367-E

Title: Recovery apparatus for drilling and excavation application and related methods

Description:
FIELD OF INVENTION 
     The present invention relates to a recovery apparatus for drilling and excavation applications comprising a recovery tank, at least one pump and at least one motor. The invention also relates to a continuous recovery system for recycling solid particulate materials and related methods. 
     BACKGROUND OF THE INVENTION 
     During the drilling of a well, it is commonplace to process the drilling mud returns to remove undesired drilled cuttings or solids utilizing a shale shaker or the like. The shale shaker is the primary piece of equipment which separates the drilling solids from the mud. It is also desirable to produce a mud with a low drilled solids content. By recycling the large drilled solids in the shale shaker, thin sizes of drilled solids are produced and thereby build up the solids content of the mud. As the solids content increases, the mud must be thinned by adding additional water which necessitates the addition of more weighting material to maintain the mud at its desired weight. 
     In addition to removing undesired large drilled solids and producing a mud with a low drilled solids content, it is also desirable to recover and recycle drilling fluids and solid particulate material such as copolymer spheres or beads. The beads are usually circulated through the system once and then discarded. It is economically beneficial to recycle these potentially costly beads during the drilling process. It is conventional to screen the mud in a shale shaker having screens ranging in size from 10 to 200 mesh. Thus, any solid particulate materials having a particle size larger than the shale shaker screen would be removed from the system with the drilled solids. 
     Efforts have been made to deposit the drilled solids and copolymer beads into a tank containing a liquid which has a specific gravity less than that of the drilled solids but greater than that of the copolymer beads or spheres. As a result, the copolymer beads or particulate materials migrate or float to the top of the liquid and can then be skimmed from the upper portion of the vessel and then returned to the well for recirculation. In these systems, the flotation liquid in the tank requires an aqueous solution of sodium carbonate or any number of soluble salts such as sodium chloride or calcium chloride to induce the separation of the beads, liquid and drilled solids. The introduction of the more efficient shale shakers that produce finer solids has made this flotation system ineffective. This flotation system did not anticipate the problem of fine solids building up in the separating fluid zone. As these solids continue to build up, the separating liquid becomes extremely viscous or thick and will not allow the copolymer spheres to be effectively separated from the drilled cuttings. Furthermore, the sodium carbonate on the surface of the copolymer spheres which are returned to the drilling fluid will create a problem for the drilling fluid known as carbonate contamination. Carbonate contamination produces carbonic acid which reacts with the alkaline products in the drilling fluid which in turn reduce the effectiveness of drilling fluid thinners such as lignosulfonates and allow the drilling fluids to become increasingly thick and unacceptable. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a recovery apparatus for drilling and excavation applications. The apparatus comprises a recovery tank, at least one pump and at least one motor. The recovery tank has an inlet and outlet for allowing the entrance and exit of drilled solids, drilling fluids, solid particulate materials and mixtures thereof. For purposes of this invention, drilled solids are pieces of formation that are the result of the chipping and/or crushing action of the drill bit during the drilling and excavation process. Drilling fluids are circulating fluid used in rotary drilling to perform various functions during drilling operations. Solid particulate materials include, but are not limited to, lubricating copolymer beads. The recovery tank of the present invention has a cavity and a base presenting an inclined surface to the cavity. The base expedites the separation of the components of the mixture. The pump is used for pumping drilled solids, drilling fluids, solid particulate materials and mixtures thereof into the inlet of the tank, through the cavity and out of the outlet of the tank. The pump also creates the centrifugal force that allows the separation of the components in the mixture. The motor provides power to operate the pump and recovery apparatus. 
     In one embodiment of the invention, the recovery apparatus is further comprised of a motor control panel, a top portion for enclosing the cavity of the tank and a framework for supporting the tank, the pump and the motor. The motor control panel is an electrical unit used to control and power-up the electrical components of the recovery system of the present invention. 
     In another embodiment of the invention, the recovery tank has three walls and each of the three walls have upper and lower ends. The upper ends of the well are connected to the top portion of the tank to form the cavity. The lower ends of at least two of the walls are tapered toward one another thereby forming the cavity within the tank. 
     In still another embodiment, the recovery tank comprises four walls, each of the four walls has upper and lower ends and said lower ends of two walls are tapered toward one another. In yet another embodiment, the recovery tank comprises four walls, each of the four walls has upper and lower ends and the lower ends of the four walls are tapered toward one another. 
     In a further embodiment, the recovery apparatus has two motors and two pumps, whereby the second motor and second pump function as a backup. 
     In still a further embodiment, the recovery tank comprises at least one suction manifold and at least one discharge manifold. In yet a further embodiment, the recovery tank comprises a dump valve for disposing of the drilled solids. 
     The present invention also relates to a continuous recovery system for suspending, separating and collecting solid particulate material from drilled solids, drilling fluid and mixtures thereof during drilling and excavation applications. The system comprises a recovery apparatus, at least one shale shaker and at least one recovery shaker. The shale and recovery shaker is a mechanical separator that utilizes vibratory screens to separate drilled mud and its components. The shale shaker of the recovery system comprises at least one screen sizes and a manifold hydrocyclone system. There are numerous hydrocyclone systems in the market. Numerous hydrocyclone systems can be used with this invention including, but not limited to, the 4 Inch Hydrocyclone manufactured by Harrisburg. The recovery apparatus comprises a recovery tank and at least one agitation system. The recovery tank of the recovery apparatus has an inlet, an outlet, a cavity and a tapered base. The recovery shale shaker comprises at least one screen. 
     In one embodiment, the recovery system comprises a recovery apparatus comprising a recovery tank having a cavity and a base, recovery tank having at least one inlet and at least one outlet. The recovery apparatus has at least one agitation system for creating force within the tank that assists in the separation of the components of the particulate material/drilled solids mixture. The recovery system also has a manifold hydrocyclone system and at least one recovery shaker having at least one screen. The system can further comprise at least one shale shaker having at least one screen, the manifold hydrocyclone system being situated on the shale shaker. 
     In a further embodiment, a mixture of solid particulate material, drilling fluids, fine particles of drilled and drilled solids enters the shale shaker where drilled solids are separated from the mixture by the screen of the shale shaker. The remaining mixture then enters the recovery tank and is further separated by the centrifugal force created by the agitation system. The remaining mixture of the particulate material, drilled fluids and fine particles of drilled solids are transferred to the manifold hydrocyclone system wherein the particles of drilled solids are separated from the remaining mixture. The mixture then enters the recovery shaker wherein the drilled fluids and solid particulate materials are finally separated. 
     In still a further embodiment, a mixture of solid particulate material, drilling fluids, fine particles of drilled solids and drilled solids enters into the recovery tank and are separated by a force created by the agitation system. The drilled solids gravitate toward the bottom the tank. The mixture of the particulate material, drilling fluids and fine particles of drilled solids is then transferred to the manifold hydrocyclone system wherein the fine particles of drilled solids are separated from the mixture and the particulate/fluid mixture is then transferred to the recovery shaker wherein the drilling fluid is separated from the solid particulate materials. The pressure required by the hydrocyclone system to separate the fine particles of drilled solids from the mixture is from about 10 lbs. to about 200 lbs. 
     In another embodiment, the recovery tank of the recovery system has at least three walls, each of the walls having upper and lower ends and the lower ends of at least two walls are tapered toward one another thereby forming a cavity within the recovery tank. In yet another embodiment, the recovery tank can have a multitude of shapes includes rounded walls or funnel shaped walls having a tapered base. 
     In still another embodiment, the recovery tank further comprises at least one suction manifold and at least one discharge manifold and a dump valve for disposing of drilled solids situated at the base of the tank. 
     In yet another embodiment, the recovery tank comprises four walls, each of the four walls having upper and lower ends and the lower ends of at least two walls being tapered toward one another thereby forming a cavity within the recovery tank. 
     In a further embodiment, the recovery tank comprises four walls, each of said walls having upper and lower ends, and said lower ends of four walls are tapered toward one another. 
     In yet another embodiment, the recovery apparatus may have a two motor and two pump, the second motor and second pump function as a backup. The recovery tank can also have a top portion, a motor control panel and framework for supporting the tank, the pump and the motor. 
     In yet a further embodiment, the hydrocyclone system of the shale shaker comprises at least one cone. The hydrocyclone manifold system is a separation device that utilizes a liquid such as water, oils, diesel, synthetic or oil-based muds, salt water, etc. to create centrifugal force for separation. The manifold is a pipe with an inlet and outlet used to separate solids from liquids. The cone is a separation device wherein the drilling fluid is pumped tangentially into the cone and the cone creates fluid rotation that provides centrifugal force to separate particles by mass weight. The system also comprises conduits for connecting the recovery apparatus, the shale shaker and the recovery shaker. The conduits are tubings, pipings and the like utilized to transport the drilling components through the recovery system of the present invention. The screen size of screens in the shale shaker and the recovery shaker can be from about 2 to about 350 mesh. In yet another embodiment, the shale shaker has a series of three different mesh screens, a first screen having a screen size from about 4 to about 100 mesh, a second screen having a screen size from about 4 to about 100 mesh, and a third screen having a screen size from about 4 to about 250 mesh. In still yet another embodiment, the recovery shaker has a series of two mesh screens and the screen sizes are from about 4 to about 325 mesh. 
     In another embodiment the agitation system in the recovery system of the present material can be a geared agitator, a pump agitator, or a pneumatic agitator. In still another embodiment, the agitation system creates movement in the drilling fluid or separation liquid. In yet another embodiment, the agitation system creates a suspension within the tank whereby the solid particulate material are separated from drilled solids. In still yet another embodiment, the agitation system creates centrifugal force that assists in the separation process. In another embodiment, the agitation system creates turbulent force within the cavity to separate the components of the mixture in the tank. The agitation system provides a pressure from about 5 lbs. to about 200 lbs. to separate the components of mixture inserted in the recovery tank. The pressure is dependent on the viscosity of drilling fluid and the weight of solid particles material and the drilled solids. 
     The present invention also relates to an improved method for continuously recovering solid particulate material from drilled solids, drilling fluids and mixtures thereof during drilling and excavation applications. The method comprises: (a) inserting a mixture of solid particulate material, drilling fluids, and drilled solids of various sizes into a shale shaker having a manifold hydrocyclone system and at least one screen and separating the drilled solids from the mixture using the screen of the shale shaker, (b) directing the remaining mixture in (a) into a recovery apparatus having at least one agitation system and a recovery tank with a tapered base, and separating the solid particulate material, the drilling fluid and the fine particles of drilled solids using a force created by the agitation system; (c) directing the remaining mixture in the recovery tank to the hydrocyclone manifold wherein the fine particles of drilled solids are separated from the fluid and solid particulate materials and; (d) directing the particulate materials and fluids in (c) into a recovery shaker having at least one screen and separating the particulate material from the fluids using the screen of the recovery shaker. 
     In one embodiment, the method further comprises the step of providing a plurality of conduits for connecting the shale shaker to the recovery apparatus and the recovery apparatus to the recovery shaker. In another embodiment, the recovery tank further comprises at least one suction manifold and at least one discharge manifold and the method further comprises the step of transferring the mixture from the recovery tank to the hydrocyclone manifold system using the suction and discharge manifolds. 
     In still another embodiment, the recovery tank comprises a dump valve and the method further comprises the step of disposing of drilled solids from the tapered base of the recovery tank. 
     In yet another embodiment of the invention, the method further comprises the step of recycling the drilling fluids by reinserting the fluids from the recovery shaker into the recovery apparatus. In a still further embodiment, the clean solid particulate materials can be reused with a preexisting mud system. The method can also comprise removing the fine particles of drilled solids from the shale shaker and recovery apparatus and providing a container for retaining the drilled solids. 
     In yet a further embodiment, the recovery system comprises a structural framework for supporting the recovery apparatus and the shale and recovery shakers, and a motor control panel for operating the motor and the pump. In still a further embodiment, the shale shaker of the method of the present invention may have a series of three different mesh screens, a first screen having a screen size of 4 to about 100 mesh, a second screen having a screen size from about 4 to about 250 mesh and a third screen having a screen size of from about 4 to about 250. In yet still a further embodiment, the recovery system has a pair of two mesh screens having a screen size of 4 to 325 mesh. The agitation system can be at least one pump agitator, at least one pneumatic agitator or at least one geared agitator. 
     In still yet a further embodiment, the present invention provides a method of recovering solid particulate material such as beads from drilling fluids, fine particles of drilled solids, drilled solids and mixtures thereof. In one embodiment, the fine particles of drilled solids cannot be larger than the circumference of the inlet of the hydrocyclone system which is about 1.5 inches. The method comprises the steps of: a) inserting a mixture of solid particulate material, drilling fluids, fine particles of drilled solids and drilled solids into a recovery tank having an agitation system and separating the mixture using a force created by the agitation system and allowing the drilled solids to gravitate to the base of the tank; b) transferring the remaining mixture of solid particulate material, drilling fluids and fine particles of drilled solids to a manifold hydrocyclone system where the fine particles of drilled solids are separated from the fluid/particulate mixture material and e) separating the drilling fluid from the remaining fluid/particulate mixture in the recovery shaker to isolate and recover the solid particulate material. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the present invention and many of the attendant advantage thereof will be readily understood by reference to the following description when considered in connection with the accompanying drawings in which: 
     FIG. 1 depicts a perspective view of the recovery system in accordance with the present invention. 
     FIGS. 2a-b depict a perspective view of two different embodiments of the recovery tank of the recovery apparatus of the present invention. 
     FIG. 3 depicts a diagram view of the continuous recovery system and related methods of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and particularly, to FIG. 1 wherein a continuous recovery system in accordance with the present invention, generally designated  1 , comprises at least one shale shaker  20  with a plurality screens  21  having varying screen sizes and a manifold hydrocyclone system  22 ; a recovery apparatus  10  comprising a recovery tank  12  having a cavity  15  and a tapered base  18 , the tank  12  having an inlet  16  and outlet  17  and at least one pump  11  and at least one motor  13 ; and at least one recovery shaker  30  having a plurality of screens  31  with varying screen sizes. The recovery apparatus  10  further comprises a framework  40  for supporting the tank  12 , the pump  11  and the motor  13 . The recovery apparatus  10  may also have a motor control panel  42 . 
     The recovery tank  12  may also have a top portion  14  for enclosing the cavity  15 . 
     In a further embodiment, the recovery tank  12  comprises four walls, each of the walls having upper and lower ends, and the lower end of the two walls are tapered toward one another to form the tapered base  18 . 
     In still another embodiment, the hydrocyclone system  22  of the shale shaker  20  comprises at least one cone  24 . The screen sizes of the screens,  21  and  31 , respectively, of the shale and recovery shaker,  20  and  30  respectively, is from about 2 to about 350 mesh. In still a further embodiment, the shale shaker  20  has a series of three different mesh screens  21 , a first screen having a screen size from about 4 to about 100 mesh, a second screen having a screen size from about 4 to about 250mesh, and a third screen having a screen size from about 4 to about 250 mesh. In yet a further embodiment, the recovery shaker  30  has a pair of two mesh screens, the mesh screen  31  having a screen size from about 4 to about 325 mesh. 
     FIG. 2a depicts a perspective view of one of the embodiments of the recovery tank  12  of the recovery apparatus  10  of the present invention. In this embodiment, the recovery tank  12  has a least four walls,  50 ,  51 ,  52  and  53 , and the walls have an upper ends  50 a,  51 a,  52 a and  53 a and lower ends  50 b,  51 b,  52 b,  53 b, respectively. The lower ends  51 b and  53 b are tapered toward one another to form a tapered base  18 . The tank may have a top portion  14  for enclosing the recovery tank  12 . 
     FIG. 2b illustrates a perspective view of another embodiment of the recovery tank  12  of the recovery apparatus  10  of the present invention. In this embodiment, the recovery tank  12  comprises at least four walls,  50 ,  51 ,  52  and  53 , and the walls have an upper ends  50 a,  51 a,  52 a, and  53 a and lower ends  50 b,  51 b,  52 b and  53 b, respectively. The lower ends  50 b,  51 b,  52 b and  53 b are tapered toward one another to form a tapered base  18 . 
     FIG. 3 illustrates a diagram of the recovery system  1  of the present invention and the method for continuously recovering solid particulate material such as copolymer beads  6  from drilling fluids  7 , drilled solids  8  and mixtures thereof. The method comprises the steps of: (A) inserting a mixture of solid particulate material  6 , drilling fluid  7 , and drilled solids  8  of various sizes into a shale shaker  20  having a manifold hydrocyclone system  22  and a plurality of screens  21  with varying screen sizes; (B) separating the larger drilled solids of the mixtures using the screens  21  of the shale shaker  20 ; (C) directing the remaining mixtures into the recovery apparatus  10  having at least one pump  11 , at least one motor  13  and a recovery tank  12  with a tapered base  18 ; (D) separating the particulate material  6 , drilling fluid  7  and drilled solids  8  using the centrifugal force created by the agitation system  11 ; (E) directing the remaining mixture in the recovery tank  12  to the hydrocyclone manifold system  22  wherein in the small drilled solids or fine particles of drilled solids  8  are separated from the fluid  7  and the solid particulate materials  6 ; and (F) directing the solids particulate material  6  and drilling fluid  7  into a recovery shaker  30  having a plurality of screens sizes  31  and separating the solid particulate materials  6  from the drilling fluid  7 . 
     The system further comprises conduits  70  from connecting the shale shaker  20  to the recovery apparatus  10  and the recovery apparatus  10  to the recovery shaker  30 . 
     In one embodiment, the recovery tank  12  further comprises at least one suction manifold and at least one discharge manifold and further comprises the step of transferring the mixture from the recovery tank  12  to the hydrocyclone system  22  using the suction and discharge manifolds. 
     In another embodiment, the recovery tank comprises a dump valve and further comprises the step of disposing of the drilled solids from the tapered base  18  of the recovery tank  12  before directing the mixture to the hydrocyclone manifold system  22 . In a further embodiment, the method also comprises the step of (G) recycling the drilling fluids  7  be reinstating the fluids  7  from the recovery shaker  30  into the recovery apparatus  10 . 
     In still another embodiment, the method also comprises (H) reusing clean solid particulate material  6  with an existing mud system. In still a further embodiment, the method comprises the step of recovering the large and small drilled solids  8  from the shale shaker  20  and the recovery apparatus  10  and providing a container  80  for retaining the drilled solids  8 . 
     In yet a further embodiment, the shale shaker  20  of the recovery system  1  of the present invention comprises a series of three different mesh screens  21 , the mesh screens range from about 4 to about 325 mesh. In still yet a further embodiment, this recovery shaker  30  comprises a pair of mesh screens having a screen size from about 4 to about 325 mesh. 
     Obviously, numerous modification and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the claims appended hereto, the invention may be practiced otherwise than as specifically disclosed herein.