Unlimited Sump Systems and Methods

Abstract

A system for providing an unlimited sump offering increased capacity over conventional sump systems is disclosed. In embodiments, the unlimited sump may comprise a submersible pump or electronic submersible pump (ESP), a particle separator located upstream of the submersible pump, a low pressure sub, a high pressure sub, and a particle pump sub comprising a particle pump, and optionally providing a particle trap located downstream of the submersible pump. The particle pump may be driven by electrical, hydraulic, or pressure differential means as a result of a flow of well fluids caused by operation of the submersible pump, and the particle pump may direct all or a portion of particulate matter separated from the wellbore fluids to be reintroduced to the well fluids at a point downstream of the submersible pump, thereby bypassing the submersible pump.

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to production of hydrocarbon fluids from a wellbore. In particular, the present invention is directed to improved sump systems, and specifically to systems and methods for reintroducing particulate matter separated from well fluids to the well fluids at a location downstream of production equipment.

Background of the Invention

Fluids produced from a well often include particulate matter, such as sand, which may be detrimental to the performance of production equipment or may cause production equipment to fail, for example a submersible pump. It is typically desirable to separate the particulate matter from well fluids prior to the well fluids being ingested by equipment such as a submersible pump, as the particulate matter may negatively impact the operation of the production equipment. Accordingly, production strings often include a separator upstream of such production equipment, and typically provide a sump for collecting the particulate matter which has been separated from the well fluids.

Conventional sump systems typically provide a limited volume for storing the collected particulate matter, which may be formed, for example, by a tubular body connected to the production string. Operational characteristics of the well into which such systems may be installed may necessitate that the sump be cleared or cleaned periodically, for example if excessive amounts of particulate matter may be present in the fluids produced from the well, where such excessive amounts may consume a substantial portion of the sump or otherwise restrict a sump's ability to collect an anticipated or desired volume of particulate matter.

Consequently, there is a need for sump systems offering improved capacity and improved methods of handling particulate matter removed from well fluids.

BRIEF SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS

These and other needs in the art are addressed in one embodiment by an unlimited sump system which may comprise a submersible pump or electronic submersible pump (ESP), a particle separator located upstream of the submersible pump, a low pressure sub, a high pressure sub, and a particle pump sub comprising a particle pump, and optionally providing a particle trap located downstream of the submersible pump. The particle pump may be driven by electrical, hydraulic, or pressure differential means as a result of a flow of well fluids caused by operation of the submersible pump, and the particle pump may direct all or a portion of particulate matter separated from the wellbore fluids to be reintroduced to the well fluids at a point downstream of the submersible pump, thereby bypassing the submersible pump.

Embodiments of the unlimited sump system may provide associated methods of removing particulate matter form well fluids, which may comprise a step of providing a well string including at least a submersible pump or electronic submersible pump (ESP), a particle separator located upstream of the submersible pump, a low pressure sub, a high pressure sub, and a particle pump sub comprising a particle pump, and optionally providing a particle trap located downstream of the submersible pump. The methods may further comprise steps of circulating well fluids through the particle separator and driving the particle pump as a result of operation of the submersible pump, separating all or a portion of particulate matter included in the well fluids from the well fluids at the particle separator, receiving particulate matter separated from the well fluids at the particle pump located in the particle pump sub, directing the particulate matter received by the particle pump to bypass the submersible pump, and reintroducing the particulate matter which bypassed the submersible pump into the well fluids at a location downstream of the submersible pump.

These and other needs in the art are addressed by a system for returning particulate matter separated from a well fluid to the well fluid. The system includes a production string comprising a submersible pump. The submersible pump is configured to circulate a well fluid through the production string. The system also includes a separator. The separator is located on the production string upstream of the submersible pump. In addition, the system includes a particle pump. The particle pump is configured to receive from the separator particulate matter that has been separated from the well fluid by the separator. The particle pump is further configured to return the particulate matter to the well fluid at a location on the production string downstream of the submersible pump. In an embodiment, the particle pump is configured to be driven by electrical means as a result of the submersible pump circulating the well fluid. In another embodiment, the particle pump is configured to be driven by hydraulic means as a result of the submersible pump circulating the well fluid. In a further embodiment, the particle pump is configured to be driven by a pressure differential resulting from the submersible pump circulating the well fluid. In embodiments, the particle pump is a diaphragm pump. Embodiments also include the system having a transmission. The transmission may also have a rod. Moreover, the system may also include a turbine. In some embodiments, the circulating well fluid actuates the turbine. The actuated turbine may then actuate the transmission, and the rod actuates the diaphragm pump. Embodiments may also include the system having a cup packer.

These and other needs in the art also may be addressed by a method of returning particulate matter separated from a well fluid to the well fluid. The method includes providing a production string comprising a submersible pump and a separator, the separator located on the production string upstream of the submersible pump. The method also includes circulating the well fluid through the production string as a result of operating the submersible pump. In addition, the method includes separating particulate matter included in the well fluid from the well fluids at the separator. Additionally, the method includes receiving the particulate matter separated from the well fluid at a particle pump. Further, the method includes driving the particle pump as a result of the submersible pump circulating the well fluid. Moreover, the method includes returning the particulate matter to the well fluid at a location on the production string downstream of the submersible pump. Embodiments of the method include that driving the particle pump is performed by electrical means as a result of the submersible pump circulating the well fluid. Embodiments of the method also include that driving the particle pump is performed by hydraulic means as a result of the submersible pump circulating the well fluid. Embodiments of the method further include that driving the particle pump is performed as a result of a pressure differential resulting from the submersible pump circulating the well fluid. Additional embodiments of the method include that driving the particle pump is performed by mechanical means. Further embodiments of the method include that the particle pump is a diaphragm pump. Moreover, embodiments of the method include a transmission. In additional embodiments of the method, the transmission is a rod. Additionally, embodiments of the method include a turbine. Circulating well fluid actuates the turbine. The actuated turbine actuates the transmission, and the rod actuates the diaphragm pump. Embodiments of the method may also include a cup packer.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:

FIG. 1 illustrates an embodiment of a conventional sump system;

FIG. 2 illustrates a first embodiment of an unlimited sump system comprising an impeller that is powered via electrical means;

FIG. 3 illustrates a second embodiment of an unlimited sump system comprising an impeller that is powered via hydraulic means;

FIG. 4 illustrates a third embodiment of an unlimited sump system comprising an impeller that is powered via pressure differential means;

FIG. 5 illustrates an embodiment of an unlimited sump system with a diaphragm pump and turbine;

FIG. 6 illustrates an embodiment of an unlimited sump system a diaphragm pump and turbine;

FIG. 7 illustrates a view of an embodiment of an unlimited pump system with a diaphragm pump and turbine;

FIG. 8 illustrates a view of an embodiment of an unlimited pump system with a diaphragm pump and turbine;

FIG. 9 illustrates a view of an embodiment of an unlimited pump system with a progressive cavity pump;

FIG. 10 illustrates a view of an embodiment of an unlimited pump system with a diaphragm pump and turbine; and

FIG. 11 illustrates a view of an embodiment of an unlimited pump system with a diaphragm pump and turbine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description the term proximal is used to describe the portion of the component being referred to that is closest to a well opening, or well mouth, and the term distal is used to refer to the portion of the component being referred to that is furthest from the well opening. Additionally, the term downstream is used to describe a direction of fluid flow which is generally oriented toward a proximal direction, and the term upstream is used to describe a direction of fluid flow which is generally oriented toward a distal direction.

FIG. 1 illustrates an embodiment of conventional sump system 100, while FIGS. 2-8 illustrate three alternate embodiments of unlimited sump system 200, 300, 400, 600, respectively. Each embodiment may principally comprise particle trap 10, a submersible pump or electronic submersible pump (ESP) 20, and separator 30, wherein particle trap 10 may be located downstream of, or proximally with respect to, submersible pump 20, and separator 30 may be located upstream of, or distally with respect to, submersible pump 20. Further, each embodiment may comprise sump 40, which may be located distally with respect to separator 30.

Submersible pump 20 may be any known apparatus that may provide means for causing well fluids, which may comprise oil, gas, water, particulate matter, or other fluids or substances, to be circulated within a well in a manner that may follow a principal direction of flow toward a proximal end of submersible pump 20, thereby encouraging the well fluids to be produced from the well toward the well opening. In embodiments, submersible pump 20 may be provided with one or more inlets 21, and one or more outlets 22, such that under operational conditions, submersible pump 20 may cause the well fluids to be ingested into submersible pump 20 at the one or more inlets 21 and expelled from submersible pump 20 at the one or more outlets 22. In embodiments, both the proximal and distal ends of submersible pump 20 may be provided with one or more means of connecting submersible pump 20 to a tubular string through known types of connection, for example threaded connection.

Particle trap 10 may be any known apparatus that may provide means of collecting or trapping particulate matter included in well fluids expelled by submersible pump 20 when a rate of flow of the well fluids slows or becomes suspended. In embodiments, particle trap 10 may be provided with one or more inlets 11, and one or more outlets 12, such that under operational conditions, particle trap 10 may collect or trap particulate matter included in well fluids that may have passed through submersible pump 20 and entered particle trap 10 at the one or more inlets 11, thereby limiting or preventing the particulate matter from being reintroduced to submersible pump 20 via the one or more outlets 22 should the flow of well fluids slow or become suspended. In an embodiment, particle trap 10 may, for example, comprise an apparatus that may be the same as or similar to the particle trap disclosed by U.S. Patent Publication No. 2022/0331714, published Oct. 20, 2022, the entire contents of which is incorporated herein by reference thereto. In embodiments, both the proximal and distal ends of particle trap 10 may be provided with one or more means of connecting particle trap 10 to a tubular string through known types of connection, for example threaded connection.

Separator 30 may be any known apparatus that may provide means of separating particulate matter included in well fluids being circulated by submersible pump 20 from the well fluids prior to the well fluids being ingested by submersible pump 20. In embodiments, separator 30 may be provided with one or more fluid inlets 31, one or more fluid outlets 32, and one or more particle outlets 33, such that under operational conditions, separator 30 may prevent all or a portion of particulate matter included in the well fluids from entering submersible pump 20 after the well fluids have exited separator 30 at the one or more fluid outlets 32 and the separated particulate matter has exited separator 30 at the one or more particle outlets 33, thereby limiting or preventing the particulate matter from being ingested by submersible pump 20. In an embodiment, separator 30 may, for example, comprise an apparatus that may be the same as or similar to the particle separator disclosed by U.S. Provisional Patent Application No. 63/469,664, filed May 30, 2023, the entire contents of which is incorporated herein by reference thereto. In embodiments, both the proximal and distal ends of separator 30 may be provided with one or more means of connecting separator 30 to a tubular string through known types of connection, for example threaded connection.

Sump 40 may be any known sump apparatus which may provide means of collecting particulate matter that may have been separated by separator 30 and discharged from separator 30 at the one or more particle outlets 33. For example, sump 40 may be formed from a generally tubular body that may provide a desired volume for collecting particulate matter, such that the volume of sump 40 may be determined based upon one or more characteristics of the geological formation from which the well into which sump system 100, or unlimited sump system 200,300,400,600 may be disposed. In embodiments, the proximal end of sump 40 may be provided with one or more means of connecting sump 40 to a tubular string through known types of connection, for example threaded connection. In contrast to conventional sump system 100, unlimited sump system 200,300,400,600 may be provided with additional components, which together may provide unlimited sump system 200,300,400,600 with an increased or unlimited capacity in comparison to conventional sump system 100, by providing unlimited sump system 200,300,400,600 with means for transporting all or a portion of the particulate matter separated by separator 30 downstream of submersible pump 20, thereby allowing the separated particulate matter to bypass submersible pump 20 instead of being collected within sump 40.

As shown in FIGS. 2-8, among these additional components, unlimited sump system 200,300,400,600 may be provided with high pressure sub 220,320,420, low pressure sub 240,340,440, and particle pump sub 260,360,460, with each individual embodiment of the high pressure sub, low pressure sub, and impeller sub components differing in the manners that will be described below.

Common among each embodiment of unlimited sump system 200,300,400,600 both the proximal and distal ends of high pressure sub 220,320,420, low pressure sub 240,340,440, and particle pump sub 260,360,460 may be provided with one or more means of connecting high pressure sub 220,320,420, low pressure sub 240,340,440, and particle pump sub 260,360,460 to a tubular string through known types of connection, for example threaded connection. As illustrated in FIGS. 2-8, high pressure sub 220,320,420 may be installed on unlimited sump system 200,300,400,600 between submersible pump 20 and particle trap 10, low pressure sub 240,340,440 may be installed on unlimited sump system 200,300,400,600 between submersible pump 20 and separator 30, and particle pump sub 260,360,460 may be installed on unlimited sump system 200,300,400,600 at a distal end of separator 30, which may be located between separator 30 and sump 40 (not shown).

Additionally, among each embodiment of unlimited sump system 200,300,400,600 low pressure sub 240,340,440 may be fitted with one or more sealing or packer elements 241,341,441 which may separate an annular volume located distally in relation to sealing or packer elements 241,341,441 from an annular volume located proximally in relation to sealing or packer elements 241,341,441 when unlimited sump system 200,300,400,600 is disposed within a wellbore, such that each of the one or more sealing or packer elements 241,341,441 may engage with a wall of a wellbore (not shown) or a liner lining a wellbore (not shown).

Further, among the embodiments, low pressure sub 240,340,440 may be formed to provide one or more internal flow channels 242,342,442 through which well fluid may enter low pressure sub 240,340,440 from the one or more fluid outlets 32 of separator 30, and exit low pressure sub 240,340,440 in the annular volume located proximally in relation to sealing or packer elements 241,341,441.

Under operational conditions, submersible pump 20 may cause well fluids to circulate through unlimited sump system 200,300,400,600 generally following the fluid paths illustrated in FIGS. 2-4. As shown, fluid may enter unlimited sump system 200,300,400,600 at the one or more inlets 31 of separator 30, wherein the fluid may follow the path illustrated as path 201a,301a,401a. As disclosed by U.S. Provisional Patent Application No. 63/469,664, this flow path may, for example, comprise a vortex flow pattern through an inner portion 276, 376, 476 of separator 30 resulting in separated particulate matter being biased to be discharged from separator 30 at the one or more particle outlets 33, while well fluid freed at least in part of the particulate matter may be discharged from separator 30 at the one or more fluid outlets 32, thereafter flowing through internal flow channels 242,342,442 of low pressure sub 240,340,440 into the annular volume located proximally in relation to sealing or packer elements 241,341,441. The well fluids may next follow the path illustrated as path 201b,301b,401b, whereby the well fluid may enter submersible pump 20 at the one or more inlets 21, after which the well fluids may become pressurized by submersible pump 20 and discharged from submersible pump 20 at the one or more outlets 22. The well fluids may then follow the path illustrated as path 201c 301c,401c, such that the pressurized well fluids being discharged from submersible pump 20 at the one or more outlets 22 may enter a distal end of particle trap 10 at the one or more inlets 11, travel through particle trap 10, and exit particle trap 10 at the one or more outlets 12, thereafter following a path to a surface location where the well fluids may be produced from the well.

Further under operational conditions and similar among the embodiments, the particulate matter separated by separator 30 that may be discharged at the one or more particle outlets 33 may enter a proximal portion of particle pump sub 260,360,460. Upon entering particle pump sub 260,360,460, all or a portion of the separated particulate matter may be transported to high pressure sub 220,320,420 via particle pump 261,361,461 in a manner specific to each embodiment that will now be described, or alternatively, all or a portion of the separated particulate matter may exit particle pump sub 260,360,460 through bypass channel 262,362,462 for collection within sump 40, for example if operation of particle pump 261,361,461 might be impeded. In the embodiments, diverter 263,363,463 may direct the particulate matter exiting separator 30 toward particle pump 261,361,461.

In the embodiment illustrated in FIG. 2, particle pump sub 260 may be provided with an electric-driven particle pump 261 that may transport all or a portion of the particulate matter entering particle pump sub 260 to a distal portion of high pressure sub 220. In such an embodiment, low pressure sub 240 may be provided with electric drive 243. As illustrated, an impeller 277 of electric drive 243 may be located within a portion of internal flow channel 242 of low pressure sub 240, such that under operational conditions as well fluids are drawn through low pressure sub 240 as a result of submersible pump 20, the impeller 277 of electric drive 243 may cause electric drive 243 to generate a voltage differential. This voltage differential may be communicated to electric-driven particle pump 261 via one or more electrical lines 250, which may in turn cause electric-driven particle pump 261 to ingest particulate matter entering particle pump sub 260 and subsequently transport the ingested particulate matter to high pressure sub 220 via bypass line 205.

In the embodiment illustrated in FIG. 3, particle pump sub 360 may be provided with a hydraulically-driven particle pump 361, which may transport all or a portion of the particulate matter entering particle pump sub 360 to a distal portion of high pressure sub 320. In such an embodiment, low pressure sub 340 may be provided with hydraulic drive 343. As illustrated, an impeller 377 of hydraulic drive 343 may be located within a portion of internal flow channel 342 of low pressure sub 340, such that under operational conditions as well fluids are drawn through low pressure sub 340 as a result of submersible pump 20, the impeller 377 of hydraulic drive 343 may cause hydraulic drive 343 to circulate hydraulic fluid through hydraulic lines 350a,b, which may in turn communicate with hydraulic-driven particle pump 361, thereby causing hydraulic-driven particle pump 361 to ingest particulate matter entering particle pump sub 360 and subsequently transport the ingested particulate matter to high pressure sub 320 via bypass line 305.

In the embodiment illustrated in FIG. 4, particle pump sub 460 may be provided with a pressure differential-driven particle pump 461 that may transport all or a portion of the particulate matter entering particle pump sub 460 to a proximal portion of high pressure sub 420. In such an embodiment, a portion of the well fluids exiting submersible pump 20 may be directed from a distal portion of high pressure sub 420 toward pressure differential-driven particle pump 461 via high pressure line 450a, and thereafter from pressure differential-driven particle pump 461 toward low pressure sub 440 via low pressure line 450b. In this manner, a portion of the well fluids exiting submersible pump 20 may be siphoned away from the principal fluid flow 401a,b,c in order to drive pressure differential-driven particle pump 461, and subsequently be reintroduced to the principal fluid flow 401a,b,c at low pressure sub 440. Accordingly, the pressure differential between the one or more inlets 21 and the one or more outlets 22 of submersible pump 20 may be employed to cause pressure differential driven pump 461 to ingest particulate matter entering particle pump sub 460 and subsequently transport the ingested particulate matter to a proximal portion of high pressure sub 420 via bypass line 405. In an embodiment, it may be desirable to locate the delivery of particulate matter via bypass line 405 downstream, or proximally in relation to, high pressure line 450a in order to reduce or eliminate any change of particulate matter entering high pressure line 450a, which may negatively impact the performance of pressure differential-driven pump 461.

FIGS. 5-8, 10, and 11 illustrate an embodiment of unlimited sump system 600 having cup packer 505, turbine 510, transmission 515, and diaphragm pump 525. In embodiments as shown, the particle pump is diaphragm pump 525. In further embodiments as shown, transmission 515 includes rod 520.

As shown in FIGS. 5-8, 10, and 11, the particle pump is diaphragm pump 525. In an embodiment of operation of unlimited sump system 600, well fluids enter at production inlet 500. The well fluids flow from production inlet 500 to cup packer 505. Cup packer 505 diverts the flow of the well fluids through the center to turbine 510. The flow of the well fluids actuates (i.e., turns) turbine 510. At least a portion or substantially all of the well fluids then flow around transmission 515 and diaphragm pump 525. By the turning (i.e., spinning) of turbine 510, transmission 515 is actuated. It is to be understood that the arrows show the direction of fluid flow. Actuation of transmission 515 actuates rod 520 of transmission 515. Rod 520 is connected to or in contact with diaphragm pump 525. Movement of rod 520 actuates diaphragm pump 525. Diaphragm pump 525 may be any suitable diaphragm pump. In an embodiment, diaphragm pump 525 is a positive displacement pump. Diaphragm pump 525 has first chamber 580 and second chamber 590. Sand 570 is disposed in first chamber 580. Actuation of diaphragm pump 525 by rod 520 of turbine 510 displaces sand 570 from first chamber 580 to second chamber 590. The embodiments of FIGS. 5, 7, and 10 are illustrations of unlimited sump system 600 with sand 570 in first chamber 580 before diaphragm pump 525 displaces sand 570 from first chamber 580 to second chamber 590. The embodiments of unlimited sump system 600 shown in FIGS. 6, 8, and 11 are illustrations of unlimited sump 600 with sand 570 having been displaced by diaphragm pump 525 from first chamber 580 to second chamber 590, with displaced sand 570 shown disposed in second chamber 590. Second chamber 590 is connected to control line 530. Actuation of diaphragm pump 525 also displaces sand 570 from second chamber 590 to control line 530. As shown in the embodiments of unlimited sump system 600 shown in FIGS. 6, 8, and 11, sand 570 in control line 530 is displaced by diaphragm pump 525 to separator 30. Sand 570 is separated in separator 30 and exits separator 30 via control line by-pass 535. Sand 570 is displaced back into the flow stream above submersible pump (ESP) 20 via control line by-pass 535. Well fluid separated from sand 570 by separator 30 flows around submersible pump (ESP) 20 after exiting separator 30 and is displaced into the flow stream.

FIG. 9 illustrates an embodiment of unlimited sump system 600 having cup packer 505, turbine 510, transmission and clutch 550, seals 545 and 555, and progressive cavity pump (PCP) 560. In embodiments as shown, the particle pump is progressive cavity pump (PCP) 560.

As shown in FIG. 9, the particle pump is progressive cavity pump (PCP) 560. In an embodiment of operation of unlimited sump system 600, well fluids enter at production inlet 500. The well fluids flow from production inlet 500 to cup packer 505. Cup packer 505 diverts the flow of the well fluids through the center to turbine 510. The flow of the well fluids actuates (i.e., turns) turbine 510. At least a portion or substantially all of the well fluids then flow around transmission and clutch 550 and progressive cavity pump (PCP) 560. By the turning (i.e., spinning) of turbine 510, transmission and clutch 550 is actuated. It is to be understood that the arrows show the direction of fluid flow. Actuation of transmission and clutch 550 actuates progressive cavity pump (PCP) 560. Seal 545 is disposed between transmission and clutch 550 and turbine 510. In alternative embodiments, more than one seal 545 is disposed between transmission and clutch 550 and turbine 510. Seal 555 is disposed between transmission and clutch 550 and progressive cavity pump (PCP) 560. In alternative embodiments, more than one seal 555 is disposed between transmission and clutch 550 and progressive cavity pump (PCP) 560. Transmission and clutch 550 is connected to or in contact with progressive cavity pump (PCP) 560. Progressive cavity pump (PCP) 560 may be any suitable progressive cavity pump. As illustrated, sand 570 disposed in sump 40 is displaced into interior sand section 593 of progressive cavity pump (PCP) 560 when progressive cavity pump (PCP) 560 is actuated. Progressive cavity pump (PCP) 560 is connected to control line 530. Actuation of progressive cavity pump 560 displaces sand 570 from sump 40 through progressive cavity pump 560 to control line 530. As shown in the embodiments of unlimited sump system 600 shown in FIG. 9, sand 570 in control line 530 is displaced by progressive cavity pump (PCP) 560 to separator 30. Sand 570 is separated in separator 30 and exits separator 30 via control line by-pass 535. Control line by-pass 535 is a by-pass line around cup packer 505. Sand 570 is displaced back into the flow stream above submersible pump (ESP) 20 via control line by-pass 535. Well fluid separated from sand 570 by separator 30 flows around submersible pump (ESP) 20 after exiting separator 30 and is displaced into the flow stream.

Embodiments of unlimited sump system 200,300,400,600 may provide associated methods of returning particulate matter removed from well fluids to the well fluids. The methods may commonly comprise a step of providing a well string including at least a submersible pump or electronic submersible pump (ESP), a particle separator located upstream of the submersible pump, a low pressure sub, a high pressure sub, and a particle pump sub comprising a particle pump, and optionally providing a particle trap located downstream of the submersible pump. Further, the methods may each comprise steps of circulating well fluids through the particle separator and driving the particle pump as a result of operation of the submersible pump, separating all or a portion of particulate matter included in the well fluids from the well fluids at the particle separator, directing well fluids freed at least in part of the particulate matter from the separator to the submersible pump, receiving particulate matter separated from the well fluids at the particle pump located in the particle pump sub, directing the particulate matter received by the particle pump to bypass the submersible pump, and reintroducing the particulate matter that bypassed the submersible pump into the well fluids freed at least in part of the particulate matter at a location downstream of the submersible pump. Further, the methods may each comprise optional steps of collecting particulate matter not received by the particle pump into a sump.

The method specifically associated with embodiments of unlimited sump systems 200, 300, 400, and 600 may vary with respect to how the particle pump may be driven. For example, a method associated with unlimited sump system 200 may comprise additional steps of generating a voltage differential by driving an electric drive as a result of a flow of well fluids through the low pressure sub, communicating the voltage differential to the particle pump via one or more electric lines connecting the electric drive and particle pump, and powering the particle pump by the voltage differential. Similarly, a method associated with unlimited sump system 300 may comprise additional steps of circulating a hydraulic fluid by driving a hydraulic drive as a result of a flow of well fluids through the low pressure sub, communicating the circulation of hydraulic fluid to the particle pump via hydraulic lines connecting the hydraulic drive and particle pump, and powering the particle pump by the circulation of hydraulic fluid. Alternatively, a method associated with unlimited sump systems 400 may comprise additional steps of siphoning a portion of the well fluids freed at least in part of the particulate matter from a location downstream of the submersible pump, directing the siphoned portion of the well fluids through a particle pump, returning the siphoned portion of the well fluids to the well fluids freed at least in part of the particulate matter at a location upstream of the submersible pump, and powering the particle pump by the siphoned portion of the well fluids. Further alternatively, a method associated with unlimited sump systems 600 may comprise additional steps of siphoning a portion of the well fluids freed at least in part of the particulate matter from a location downstream of the submersible pump, directing the siphoned portion of the well fluids to actuate a particle pump. For the embodiments of unlimited sump system 600, the particle pump is a mechanical pump such as a diaphragm pump actuated by a transmission or a progressive cavity pump. Unlimited sump 600 also includes returning the siphoned portion of the well fluids to the well fluids freed at least in part of the particulate matter at a location upstream of the submersible pump, and powering the particle pump by the siphoned portion of the well fluids.

Embodiments of the unlimited sump system and their associated methods may provide a principal advantage over conventional sump systems by offering an extended service life in comparison to the conventional sump systems. This extended service life may offer associated cost advantages that may result from the unlimited sump systems experiencing less service downtime, for example, and without limitation, in order to clean or clear a sump. Further, the novel components of the unlimited sump system, for example the high pressure sub, low pressure sub, particle pump sub, and the associated fluid, hydraulic, or electrical lines specific to each embodiment, may be retrofitted onto installed conventional sump systems.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A system for returning particulate matter separated from a well fluid to the well fluid, comprising: a production string comprising a submersible pump, the submersible pump configured to circulate a well fluid through the production string;a separator, the separator located on the production string upstream of the submersible pump; anda particle pump, the particle pump configured to receive from the separator particulate matter that has been separated from the well fluid by the separator, wherein the particle pump is further configured to return the particulate matter to the well fluid at a location on the production string downstream of the submersible pump.

2. The system of claim 1, wherein the particle pump is configured to be driven by electrical means as a result of the submersible pump circulating the well fluid.

3. The system of claim 1, wherein the particle pump is configured to be driven by hydraulic means as a result of the submersible pump circulating the well fluid.

4. The system of claim 1, wherein the particle pump is configured to be driven by a pressure differential resulting from the submersible pump circulating the well fluid.

5. The system of claim 1, wherein the particle pump is a diaphragm pump.

6. The system of claim 5, further comprising a transmission.

7. The system of claim 6, wherein the transmission comprises a rod.

8. The system of claim 6, further comprising a turbine.

9. The system of claim 8, wherein the circulating well fluid actuates the turbine, and wherein the actuated turbine actuates the transmission, and wherein the rod actuates the diaphragm pump.

10. The system of claim 1, further comprising a cup packer.

11. A method of returning particulate matter separated from a well fluid to the well fluid, comprising: (A) providing a production string comprising a submersible pump and a separator, the separator located on the production string upstream of the submersible pump;(B) circulating the well fluid through the production string as a result of operating the submersible pump;(C) separating particulate matter included in the well fluid from the well fluids at the separator;(D) receiving the particulate matter separated from the well fluid at a particle pump;(E) driving the particle pump as a result of the submersible pump circulating the well fluid; and(F) returning the particulate matter to the well fluid at a location on the production string downstream of the submersible pump.

12. The method of claim 11, wherein driving the particle pump is performed by electrical means as a result of the submersible pump circulating the well fluid.

13. The method of claim 11, wherein driving the particle pump is performed by hydraulic means as a result of the submersible pump circulating the well fluid.

14. The method of claim 11, wherein driving the particle pump is performed as a result of a pressure differential resulting from the submersible pump circulating the well fluid.

15. The method of claim 11, wherein driving the particle pump is performed by mechanical means.

16. The system of claim 15, wherein the particle pump is a diaphragm pump.

17. The system of claim 16, further comprising a transmission.

18. The system of claim 17, wherein the transmission comprises a rod.

19. The system of claim 18, further comprising a turbine, wherein the circulating well fluid actuates the turbine, and wherein the actuated turbine actuates the transmission, and wherein the rod actuates the diaphragm pump.

20. The system of claim 15, further comprising a cup packer.