Patent Publication Number: US-6698521-B2

Title: System and method for removing solid particulates from a pumped wellbore fluid

Description:
This application is a Divisional of patent application Ser. No. 09/625,241 filed on Jul. 25, 2000 now U.S. Pat. No. 6,394,183. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to submersible pumping systems that are used to raise production fluids from a well, and particularly to a system and method for removing solid particulates, such as sand, from the wellbore fluid upstream from the pump. The particulates may then be reinjected into the wellbore fluid stream discharged from the pump. 
     BACKGROUND OF THE INVENTION 
     In producing petroleum and other useful fluids from production wells, a variety of submersible pumping systems are used to raise the fluids collected in a well. Generally, a wellbore is drilled into the earth at a production formation and lined with a wellbore casing. The casing generally includes perforations through which the production fluids may flow from the production formation into the wellbore. The fluids that collect in the wellbore are raised by the submersible pumping system to another zone or to a collection point above the surface of the earth. 
     One exemplary submersible pumping system is an electric submersible pumping system that utilizes a submersible electric motor and a submersible pump. The system further may include other components, such as sensor equipment, gas separators, and motor protectors for isolating the motor oil from the well fluids. 
     Also, a connector is used to connect the pumping system to a deployment system. A variety of deployment systems may be used to deploy the pumping system within a wellbore. For example, cable, coil tubing or production tubing may be utilized. 
     Power is supplied to the submersible electric motor via a power cable that runs along the deployment system. Typically, the power cable is banded or supported along either the outside or the inside of the deployment system. Generally, the power cable is routed to the electric motor to supply electric power thereto, and the motor powers the submersible pump by an appropriate drive shaft. 
     In many wellbore environments, the production fluids contains particulates, such as sand. These solid particulates are drawn into the submersible pump through a pump intake along with the production fluid. However, the solids can cause detrimental wear to the internal components of the submersible pump. For example, if a centrifugal type pump is used, the solid particulates can create substantial wear on the impellers, the diffusers and other internal pump components. 
     Submersible pumping systems also are used to inject water from one zone within a well to a second zone within the well, or to dispose of surface water to an existing aquifer. If the geologic formation surrounding the first zone is sandstone, then it is very likely that sand will be injected into the second zone. Forcing sand into an aquifer eventually cause the aquifer to plug and no longer accept fluid. 
     It would be advantageous to have a system and method for removing at least a portion of the solid particulates from the wellbore fluid upstream from the pump. It would also be advantageous to have a system that could reinject the solid particulates into the fluid stream discharged from the pump, if desired, or produce a fluid stream free of at least a portion of solid particulates. 
     SUMMARY OF THE INVENTION 
     The present invention features a system for pumping a wellbore fluid while reducing the detrimental effects of solids dispersed in the wellbore fluid. The system includes a submersible pumping system having a plurality of sequentially connected components arranged for deployment in a wellbore. Specifically, the submersible pumping system includes a submersible motor, a submersible pump and a solids separator. The solids separator is disposed to remove solid particulates prior to entrance of the solids into the submersible pump. 
     According to another aspect of the invention, a submersible pumping system is provided to reduce wear on a submersible pump by routing solid particulates around the pump. The system includes a submersible pump able to intake a fluid and discharge the fluid in a fluid discharge stream. Additionally, a particulate separator is disposed to receive wellbore fluid prior to entrance of the fluid into the submersible pump. The particulate separator has a separator region and a particulate collection region where the solid particulates may be concentrated. 
     The system further includes a pressure reduction device having a venturi disposed to receive the fluid stream discharged from the submersible pump. This creates a low pressure region proximate the venturi that permits reinjection of the solid particulates into the wellbore fluid discharged by the pump. A bypass is connected between the particulate collection region of the particulate separator and the low pressure region proximate the venturi. The low pressure draws a concentrated mixture of solid particulates and fluid from the particulate collection region through the bypass and into the fluid stream being discharged from the submersible pump. In other words, solid particulates are routed around the submersible pump to reduce wear on internal pump components. 
     According to another aspect of the present invention, a method is provided for pumping a production fluid. The method includes powering a submersible pump with a submersible motor, and intaking a wellbore fluid intermediate the submersible pump and a fluid intake. The method further includes separating solid particulates from the wellbore fluid to be pumped by the submersible pump. Following separation, the solid particulates may be reinjected into a fluid discharge stream of the submersible pump. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and: 
     FIG. 1 is a front elevational view of a pumping system disposed in a wellbore, according to an embodiment of the present invention; 
     FIG. 2 is a cross-sectional view of a solids separator, according to an embodiment of the present invention; 
     FIG. 3 is a front elevational view of a pumping system positioned in a wellbore, according to an embodiment of the present invention; 
     FIG. 4 is a front view of the solids separator illustrated in FIG. 3 showing internal components in dashed lines; 
     FIG. 4A is a cross-sectional view taken generally along line  4 A— 4 A of FIG. 4; 
     FIG. 5 is a cross-sectional view of a pressure reduction device as utilized in the system illustrated in FIG. 1 or  3 ; 
     FIG. 6 is an alternate embodiment of a low pressure device as utilized in the system illustrated in FIG. 1 or  3 ; 
     FIG. 7 is a front elevational view of a pumping system disposed in a wellbore, according to an embodiment of the present invention; 
     FIG. 8 is a front elevational view of a pumping system disposed in a wellbore to pump fluids from one region of the wellbore to another region of the wellbore, according to an embodiment of the present invention; 
     FIG. 8A is a front elevational view of an alternative embodiment of a pumping system disposed in a wellbore to pump fluids from one region of the wellbore to another region; 
     FIG. 9 is a partially cut-away view of an integral solids separator and gas separator, according to an embodiment of the present invention; 
     FIG. 10 is a front elevational view of a pumping system disposed in a wellbore with the solids separator disposed separate from the submersible motor and pump, according to an embodiment of the present invention; 
     FIG. 10A is a front elevational view of an alternative embodiment of a pumping system with the solids separator disposed separate from the submersible motor and pump, according,to an embodiment of the present invention; 
     FIG. 11 is a functional diagram of a hydrocyclone separator utilized with the present invention; 
     FIG. 11A is a front elevational view of the hydrocyclone illustrated in FIG.  11  and showing internal features in dashed lines; 
     FIG. 11B is a cross-sectional view of the hydrocyclone taken generally along line  11 B— 11 B of FIG. 11A; 
     FIG. 11C is a partial front elevational view of a solids separator utilizing the hydrocyclone of FIG. 11A; 
     FIG. 11D is a cross-sectional view of the solids separator taken generally along line  11 D— 11 D of FIG. 11C; and 
     FIG. 12 is a front elevational view of a pumping system disposed in a wellbore to pump fluids from one region of the wellbore to another utilizing the hydrocyclone separator of FIG. 11A, according to an embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring generally to FIG. 1, a pumping system  14  is illustrated according to an exemplary embodiment of the present invention. Pumping system  14  is a submersible pumping system designed for deployment in a subterranean environment for pumping fluids. Pumping system  14  may comprise a variety of components depending on the particular application or environment in which it is used. However, system  14  typically includes at least a submersible pump  15  and a submersible motor  16 . 
     Pumping system  14  is designed for deployment in a well  17  within a geological formation  18  containing desirable production fluids, such as petroleum. In a typical application, a wellbore  20  is drilled and lined with a wellbore casing  22 . Pumping system  14  may be submerged in a desired fluid within wellbore  20  at a desired location for pumping the wellbore fluids to another zone or directly to the surface of the earth. 
     As illustrated, submersible pumping system  14  typically includes other components. For example, submersible motor  16  may be connected to a motor protector  24  that serves to isolate the motor oil contained in submersible motor  16  from the wellbore fluids. Additionally, system  14  includes a solids separator  26  and a connector  28  designed to connect the string of submersible pumping components to a deployment system  30 . 
     In the illustrated embodiment, deployment system  30  includes tubing, such as production tubing  32 , through which the wellbore fluids are pumped to another zone or to the surface of the earth. Generally, a power cable (not shown) extends along production tubing  32  and is connected to submersible motor  16  to provide electric power thereto. 
     In the preferred embodiment, solids separator  26  is combined with a pump intake  34 . Solids separator  26  is disposed on an upstream side of submersible pump  15 , such that wellbore fluid may be drawn through pump intake  34  by submersible pump  15 . When wellbore fluid enters pump intake  34  it moves into a solids separation region  36  (see FIG. 2) where solid particulates are separated from the incoming wellbore fluid. The solid particulates are moved to or settle to a particulate collection region  38  of solids separator  26 . 
     The wellbore fluid, from which the solid particulates, such as sand, have been removed, is drawn into submersible pump  15  and pumped through an outlet end  40  as a discharged fluid stream. The discharged fluid stream is directed into production tubing  32  and a pressure reduction device  42 , e.g. a jet pump, that creates a reduced pressure region  44  downstream of submersible pump  15 . 
     A bypass  46 , such as a bypass conduit  48  is connected between particulate collection region  38  and reduced pressure region  44 . Specifically, bypass conduit  48  extends into fluid communication with solids separator  26  and includes a bypass inlet  50  disposed proximate particulate collection region  38 . Additionally, bypass conduit  48  includes a bypass outlet  52  disposed proximate reduced pressure region  44  created by pressure reduction device  42 . 
     As the discharged fluid from submersible pump  15  is forced through pressure reduction device  42 , a reduced pressure at reduced pressure region  44  is created. This reduced pressure creates a suction or vacuum in bypass conduit  48  that draws a concentrated mixture of solid particulates and fluid into bypass conduit  48  via bypass inlet  50 . Thus, the solid particulates are removed from solids separator  26  at a position upstream of submersible pump  15 , drawn through bypass conduit  48 , and drawn, i.e. reinjected, into the discharged wellbore fluid stream at a position downstream from submersible pump  15 . In this manner, the solid particulates can be routed past the working components of submersible pump  15  while still being carried away by the discharged fluid from pump  15 . 
     Referring generally to FIG. 2, an exemplary embodiment of solids separator  26  is illustrated. In this embodiment, solids separator  26  includes an upper connector end  54  by which solids separator.  26  is connected to submersible pump  15 . Upper connector end  54  may include a plurality of threaded apertures  55  for receiving fasteners, such as bolts, as is commonly known to those of ordinary skill in the art. Similarly, solids separator  26  includes a lower connector end  56  configured for connection to motor protector  24 . Lower connector end  56  may include, for example, a flange  58  having a plurality of openings  60  for receiving fasteners, such as bolts  62 . 
     Solids separator  26  includes an outer housing  64  extending between upper connection region  54  and lower connection region  56 . Outer housing  64  may be connected to upper connector end  54  and lower connection end  56  by, for instance, threaded engagement at a pair of threaded regions  66 . Outer housing  64  also forms the outer wall of a hollow interior region  68 . Hollow interior  68  includes solids separation region  36  and particulate collection region  38 . 
     An inducer  70  is disposed in hollow interior  68 , and is designed to impart a generally circular, e.g. helical, motion to the wellbore fluid that passes through hollow interior  68 . The circular motion creates centrifugal forces which act on the heavier, solid particulate matter to move the solids radially outward. As the solid particulates are forced outwardly, they pass through a baffle wall  72  having a plurality of openings  74 . The solid particulates then are allowed to settle through an outer radial passage  76  formed between baffle wall  72  and outer housing  64 . The sand and other solid materials settle into particulate collection region  38  to form a slurry that may be intaken through bypass inlet  50 . 
     In the illustrated embodiment, inducer  70  includes a generally helical vane  78  mounted to a rotatable drive shaft  80 . Drive shaft  80  is the power shaft that ultimately extends from submersible motor  16  through hollow interior  68  to submersible pump  15  to power submersible pump  15 . In this embodiment, drive shaft  80  is supported by a pair of bearings  82  disposed in upper connector end  54  and lower connector end  56 , respectively. Furthermore, helical vane  78  is mounted to drive shaft  80  for rotation therewith. As drive shaft  80  rotates, helical vane  78  induces the fluid within hollow interior  68  to circulate as it moves upwardly through hollow interior  68 . 
     It should be noted that a variety of inducers  70  may be implemented. For example, inducer  70  can be mounted in a stationary position relative to baffle wall  72  and outer housing  64 , while drive shaft  80  is allowed to freely rotate within an axial opening formed through inducer  70 . In this embodiment, the wellbore fluid pulled through solids separator  26  by submersible pump  15  similarly would be induced into a circulating upward pattern of motion during movement through hollow interior  68 . A variety of other inducer styles, including angled pump intake openings can be utilized to induce a desired fluid motion within solid separator  26 . 
     In operation, submersible motor  16  turns drive shaft  80  to power submersible pump  15 . Submersible pump  15  draws wellbore fluid through a plurality of intake openings  84  that serve to form pump intake  34 . In the embodiment illustrated, intake openings  84  are disposed through lower connector end  56 , and extend between hollow interior  68  and the wellbore environment external to pumping system  14 . 
     As the wellbore fluid is drawn through intake openings  84 , it enters hollow interior  68  and is induced into a circulating pattern of motion by inducer  70  during its upward movement through hollow interior  68 . The heavier solid particulates move radially outward through openings  74  of baffle wall  72  and settle to particulate collection region  38 . 
     The wellbore fluid from which the solid particulates have been removed, is continually drawn upward through a plurality of separator outlets  86  and into submersible pump  15 . Submersible pump  15  moves the wellbore fluid upwardly and discharges a wellbore fluid stream through outlet end  40 . The discharged fluid stream is forced through pressure reduction device  42  to cause a lower pressure at reduced pressure region  44 . This creates suction or partial vacuum within bypass conduit  40  that acts to draw the slurry of solid particulates into bypass inlet  50  at particulate collection region  38 . The solid particulates are drawn through bypass conduit  48  and into reduced pressure region  44  where they enter the discharged fluid stream from submersible pump  15 . Thus, many of the solid particulates within the wellbore fluid are routed past the moving components of submersible pump  15  to substantially reduce wear and damage. 
     Referring generally to FIG. 3, a preferred embodiment of pumping system  14  is illustrated. In the description of this embodiment, and the embodiments that follow, the reference numerals utilized in FIG. 1 are retained where the components are the same or similar to those described with reference to FIG.  1 . 
     In the embodiment illustrated in FIG. 3, a high pressure line  90  as well as a second pressure reduction device  92  have been added. This arrangement is particularly helpful when there is substantial distance between bypass inlet  50  and bypass outlet  52 . High pressure line  90  is connected in fluid communication with the high pressure fluid discharged from submersible pump  15 . Preferably, high pressure line  90  includes an inlet  94  disposed generally between submersible pump  15  and pressure reduction device  42 , e.g. a venturi. High pressure line  90  also includes an outlet  96  connected to bypass inlet  50  across second pressure reduction device  92 . 
     As submersible pump  15  discharges a high pressure fluid stream, a portion of this stream is picked up by inlet  94  and forced through high pressure line  90  and second reduction pressure device  92 . When this high pressure fluid flows through second pressure reduction device  92 , a reduced pressure region  98  is created. It is desirable that device  92  be located proximate to the particulate collection region  38  such that reduced pressure region  98  may draw the solid particulates into the fluid flowing from high pressure line  90  into bypass  46 . 
     As will be explained more fully below, pressure reduction devices  42  and  92 , each preferably utilize a venturi type device, such as a jet pump, venturi, siphon or eductor, to permit rapid fluid flow through the pressure reduction device while creating a low pressure region proximate thereto. For example, the fluid in high pressure line  90  rapidly flows through a venturi  100  at second pressure reduction device  92  and into bypass conduit  48  at bypass inlet  50 .: As the fluid flows through venturi  100 , the solid particulates in particulate collection region  38  are drawn into the stream of fluid moving from pressure line  90  to bypass  46  because of the low pressure created at reduced pressure region  98  due to venturi  100 . 
     Referring generally to FIGS. 4 and 4A, an alternate embodiment of solids separator  26  is illustrated. In this embodiment, inducer  70  includes a plurality of angled or curved intakes  102  that serve to create pump intake  34 . As wellbore fluid is drawn through angled intake openings  102 , the fluid is induced into a circular pattern of flow within solid separator  26 . The heavier solid particulates generally move to the outer radial regions of the hollow interior of solids separator  26 . The solids are allowed to settle and collect in particulate collection region  38  where they are drawn into bypass conduit  48  via bypass inlet  50  at venturi  100 . The fluid from which the solid particulates have been removed is drawn upwardly into submersible pump  15  through an outlet tube  104 . The embodiment described with reference to FIGS. 4 and 4A is another example of a variety of solids separators that can be incorporated into the present invention for combination with a submersible pumping system  14 . 
     Referring generally to FIGS. 5 and 6, preferred embodiments of pressure reduction devices are described. Both of these designs utilize a venturi to create a low pressure region proximate a stream of moving fluid. Additionally, the pressure reduction devices illustrated in FIGS. 5 and 6 are described as receiving the fluid stream discharged from submersible pump  15 . However, either of these devices can be readily utilized as second pressure reduction device  92  and venturi  100  if it is necessary or desirable to use second pressure reduction device  92  for a specific pumping system design. 
     Referring now to FIG. 5, pressure reduction device  42  includes a flow through passage  110  having an upstream region  112 , a venturi  114  and an expansion region  116  on the downstream side of venturi  114 . A radial opening  118  is formed through pressure reduction device  42  at venturi  114 . 
     As fluid flows through passage  110  and venturi  114 , the velocity of the fluid increases, and thereby creates a lower pressure at reduced pressure region  44 . The reduced pressure region  44  is disposed in fluid communication with bypass outlet  52  and bypass  46  via radial opening  118 . Thus, a suction or partial vacuum is created in bypass conduit  48  to draw the solid particulate slurry therethrough and into venturi  114 . From venturi  114 , the solid particulates are carried into expansion region  116  and on through production tubing  32 . 
     In the illustrated embodiment, a side pocket mandrel  120  is utilized to direct the flow of solid particulates into venturi  114  of pressure reduction device  42 . Side pocket mandrel  120  includes a housing  122  having a passage  124  through which the solid particulates flow to bypass outlet  52 . If a side pocket mandrel  120  is utilized to create bypass outlet  52 , bypass conduit  48  may be connected with housing  122  and passage  124  by an appropriate fitting  126 . 
     Additionally, pressure reduction device  42  may be designed for selective retrieval from production tubing  32 . To this end, pressure reduction device  42  is mounted within production tubing  32  by appropriate packing  128  to permit retrieval of the pressure reduction device from the surface by, for instance, a wireline, as is commonly known to those of ordinary skill in the art. 
     Another embodiment of a pressure reduction device  42  is illustrated in FIG.  6 . In this design, a venturi also is utilized to create a low pressure area for drawing the solid particulate slurry into a fluid stream. Again, although this design is described as mounted in production tubing  32 , it also could be utilized in forming second pressure reduction device  92 . 
     In the embodiment illustrated in FIG. 6, pressure reduction device comprises a jet pump  130 . As shown, fluid discharged from submersible pump  15  flows into a jet pump nozzle  132 . Then, the fluid is forced from nozzle  132  through a narrower orifice  134 . As the fluid moves through orifice  134 , its velocity is increased, thereby creating a lower pressure in reduced pressure region  44 . Low pressure region  44  is in fluid communication with bypass  46  through an opening  136  formed through production tubing  132 . 
     The low pressure in reduced pressure region  44  draws the solid particulate mixture through conduit  48  and bypass outlet  52  into jet pump  130  for mixing with the discharged fluid stream passing through jet pump nozzle  132  and narrow orifice  134 . The discharged fluid stream and the solid particulate slurry are mixed at a throat area  138 . After flowing through throat  138 , the mixture moves into an expanded diffuser region  140 , and exits jet pump  130  through a jet pump outlet  142  for continued flow through production tubing  32 . 
     Jet pump  130  may include a latch mechanism  144 . Latch mechanism  144  maintains jet pump  130  at a specific, desired location within production tubing  32 . Furthermore, jet pump  130  also may include a wireline connector  146  to facilitate retrieval or replacement of this pressure reduction device by a wireline. 
     Referring generally to FIG. 7, a preferred embodiment of pumping system  14  is illustrated that is operable to backflush portions of the system with liquid. Occasionally, portions of the fluid flow paths of system  14  handling the solid particulate slurry may become clogged with sand or other solid particulate. Areas where flow is constricted, such as bypass conduit  48  and pressure reduction devices  42  and  92 , are especially vulnerable to clogging. Clogged fluid flow paths reduce the efficiency of the system and could lead to the formation of a complete obstruction to fluid flow. Backflushing the system directs fluid back through the system in the direction opposite to the normal direction of fluid flow, thereby dislodging the clogged particulate. Preferably, a clean liquid free of solid particulate is used as the backflush fluid. In the illustrated embodiment, the backflush is pumped down production tubing  32  from the surface. Pumping system  10  includes a check valve  148  that prevents solid particulate from being backflushed through pump  15 , possibly damaging the pump. The backflush flows through and dislodge solid particulate matter from pressure reduction device  42 , bypass conduit  48 , and pressure reduction device  92  within solids separator  26  before exiting the system through another check valve (not shown). 
     Referring generally to FIG. 8, a preferred embodiment of a pumping system  150  is illustrated that pumps wellbore fluid from a first zone  152  of wellbore  20  to a second zone  154  within wellbore  20 . Pumping system  150  removes solid particulate from the wellbore fluid prior to injection of the wellbore fluid into the second zone. Pumping system  150  utilizes a first packer  156  and a second packer  158  to isolate first zone  152  from second zone  154 . Pumping system  150  primarily occupies a third zone  160  between the first and second zones. In the illustrated embodiment, the orientation of the submersible pump  15  relative to the submersible motor  16  is reversed from previously discussed embodiments, with the submersible motor  16  being disposed above submersible pump  15 . 
     In operation, water and solid particulates flow into first zone  152  through perforations  162  in wellbore casing  22 . The water and solid particulates are drawn into solids separator  26  through intake  34 . The water is separated from the solid particulates in solids separator  26  and pumped to third zone  160  through a conduit  164  that passes through first packer  156 . The water from the third zone  160  is then drawn into submersible pump intake  166 . Water is pumped from submersible pump  15  to a second zone  154  through a discharge conduit  168  that passes through second packer  158 . A portion of the water discharged from submersible pump  15  is bypassed though high pressure line  90  to venturi  100 . The water flowing through venturi  100  produces a reduced pressure region that draws a sand and water slurry from solids separator  26  into the water discharged from submersible pump  15 . The sand and water slurry is conveyed via conduit  170  to the surface. An oil and water separator could also be used to separate a portion of any oil contained in the wellbore fluid within first zone  152  prior to pumping the fluid into second zone  154 . 
     Referring generally to FIG. 8A, an alternative embodiment of the system illustrated in FIG. 8 is shown. In this embodiment a single packer  172  is used to isolate first zone  152  from second zone  154 . 
     Fluid is drawn into wellbore  20  through perforations  162  in wellbore casing  22 . System  150  is oriented so that the fluid passes over and cools submersible motor  16  before entering intake  34  of solids separator  26 . Clean water is separated from sand and drawn via supply conduit  174  to pump intake  176 . 
     The majority of water is discharged from submersible pump  15  to second zone  154 . However, a portion of water is directed via high pressure line  90  to an eductor  167 . A sand and water slurry is drawn from solids separator  26  into the portion of water discharged from submersible pump  15  and conveyed via bypass conduit  48  to production tubing  32 . This embodiment differs from the embodiment of FIG. 6 in that sand is conveyed to the surface in production tubing  32  of deployment system  30 . An expansion chamber  178  above submersible motor  16  accommodates expansion and contraction of motor oil within submersible motor  16 . 
     In addition to solids, gases can also be found in wellbore fluids. Gas separators have been used to separate gases from production fluids. Referring generally to FIG. 9, a preferred embodiment of a solids separator with an integral gas separator  180  is illustrated. The solids separator with an integral gas separator  180  is similar to the solids separator of FIG. 2, it has an outer housing  64  with pump intake  34  though which wellbore fluids enter a hollow interior  68 . 
     Wellbore fluids, including solid particulates, are initially drawn downward within hollow interior  68  after entering through intake  34 . Wellbore liquids and gases are directed upward through a shroud  182 . However, solid particulates are unable to make the abrupt change in direction and contact a strike plate  184 . The solid particulates  186  collection particulate collection region  38 . 
     A rotatable drive shaft  80  is coupled with an inducer  70  to impart a generally circular, e.g. helical motion to the wellbore fluid. The helical motion of the wellbore fluid causes the lighter gases  188  to migrate to the center of the fluid flow while the heavier liquids  190  remain at the perimeter of the helical fluid flow. The gases at the center enter a second shroud  192  that directs the gases to the wellbore  20  through openings  194 . 
     Referring generally to FIG. 10, a preferred embodiment of a pumping system  196  is illustrated. The solids separator of pumping system  196  does not use, or even have, a rotatable shaft extending through the solids separator. Pumping system  196  includes submersible pump  15 , submersible motor  16  and solids separator  198 . 
     Submersible pump  15  draws in wellbore fluids through solid separator  198 . Wellbore fluids enter solid separator  198  through solids separator intake  200 . Solid particulates are separated from the incoming wellbore fluid in solids separator  198 . The wellbore fluid, from which the solid particulates have been removed, is drawn through a supply conduit  174  to a pump intake  166  in submersible pump  15 . The wellbore fluid is pumped through submersible pump  15  to production tubing  32 . 
     A portion of the discharged fluid stream is directed through high pressure line  90  to eductor  167 . A conduit  202  fluidicly couples the particulate collection region of solids separator  198  to the reduced pressure region of eductor  167 . The mixture of solid particulates and fluid from solids separator  198  is mixed with the discharged fluid stream in high pressure line  90  and reinjected through a discharge conduit  204  into the discharged flow stream within production tubing  32 . The solid particulate and wellbore fluid is conveyed to the surface through production tubing  32 . 
     In the illustrated embodiment, submersible motor  16  is disposed above perforations  162  in wellbore casing  20 . In this configuration, wellbore fluids flow past and cool submersible motor  16  before entering intake  34 . 
     Referring generally to FIG. 10A, an alternative embodiment of the pumping system of FIG. 10 is illustrated. In the illustrated embodiment, solids separator  198  is disposed at the bottom of pumping system  196 , in line with the other components of pumping system  196 . This configuration allows the solids separator to be as large in diameter as allowed by the casing  22 . 
     In the illustrated embodiment, pumping system  196  is disposed in wellbore  20  so that intake  34  is below perforations  162  in wellbore casing  22 . In this orientation, wellbore fluids still flow around and cool submersible motor  16  before entering intake  34 . 
     Referring generally to FIGS. 11-11D, one preferred embodiment of a solids separator is illustrated. Solids separator  198  includes a hydrocyclone separator  206  that operates more efficiently without a rotatable drive shaft extending through the hydrocyclone separator. 
     As best illustrated in FIG. 11, hydrocyclone separator  206  operates similarly to the solids separator of FIGS. 4 and 4A. A mixture  208  of solid particulate matter, i.e. sand, and fluid enters hydrocyclone separator  206  through a tangential inlet  210 . A vortex flow  212  is created within hydrocyclone separator  206  which produces centrifugal forces that act upon the solid particulate and fluid. The less dense portions of mixture  208 , i.e. fluid  213 , migrate towards the center, or core. Fluid  213  is removed from the core through a fluid outlet  214 . A solid particulate and liquid slurry  216 , a denser portion of the mixture, exits hydrocyclone separator  206  through an outlet  218 . 
     As best illustrated in FIG. 11A, hydrocyclone separator  206  is extremely elongated. The interior of hydrocyclone separator  206  is tapered, such that the interior diameter decreases as fluid flows downward through hydrocyclone separator  206 . As best illustrated in FIG. 11B, flow into the hydrocyclone separator enters targentially through targential inlet  210 . Tangential inlet  210  and the tapered sides of hydrocyclone separator  206  produce the vortex flow  212  within hydrocyclone separator  206 . 
     Referring generally to FIGS. 11C and 11D, hydrocyclone separator  206  is disposed within a housing  219  of solids separator  198 . Solids separator  198  also includes an overflow manifold  220  and an underflow manifold  222 . Overflow manifold  220  and underflow manifold  222  are used to couple fluids to and from hydrocyclone separator  206 . Overflow manifold  220  is fluidicly coupled to fluid outlet  214  and to submersible pump  15 . Submersible pump  15  provides the motive force to draw fluids through hydrocyclone separator  206 . Under flow manifold  222  is fluidicly coupled to outlet  218  and to a pressure reduction device. The reduced pressure produced by the pressure reduction device draws the slurry from the hydrocyclone separator  206  through the underflow manifold  222 . 
     The embodiment described with reference to FIGS. 11 through 11D is another example of a variety of solids separators that can be incorporated into the present invention for combination with a submersible pumping system. 
     Referring generally to FIG. 12, a pumping system is illustrated that utilizes a hydrocyclone separator to pump fluid from one region of a wellbore to another region. A single packer  172  is used to isolate a first zone  152  from a second zone  154  of the wellbore  20 . Fluid from the first zone  152  is pumped by the pumping system to the second zone, for ultimate removal from wellbore  20 . Submersible pump  15  includes a discharge head  224  that directs the discharge of the pumping system into wellbore  20 . 
     It will be understood that the foregoing description is of preferred embodiments of this invention, and that the invention is not limited to the specific forms shown. For example, a variety of submersible pumping systems may be utilized; various inducers may be implemented to separate solid particulates from the wellbore fluid; a variety of pressure reduction devices can be incorporated into the system; and one or more pressure reduction devices may be incorporated into the system at different points to facilitate movement of the solid particulates independent of the main wellbore fluid flow stream. These and other modifications may be made in the design and arrangement of the elements without departing from the scope of the invention as expressed in the appended claims.