Hydraulically Actuated Double-Acting Positive Displacement Pump System for Producing Fluids from a Wellbore

The present disclosure is direct at apparatus and systems for delivering fluids from the surface to a downhole pump within a wellbore and for delivering fluids from the pump back to the surface. In particular, the embodiments of the present disclosure comprise a slim profile pumping system that is sized for use in wellbores of various dimensions.

It is known to use reciprocating linear pumps installed in line at the bottom end of a wellbore, attaching conduit between the pump and surface collection equipment, and powering the reciprocal motion of the pump, typically of pistons deployed within a cylinder with associated flow valve controls such as one-way valves to control fluid flow within the pump subassembly, by a series of sucker rods connected end-to-end and attached at the lowest end to the pump subassembly, and at the highest end to some mechanism such as pump-jack or similar drive mechanism providing reciprocating linear motion under power from surface to the pump subassembly. The linear pumps may be a series or stages of lift pistons and packers with suitable one-way valves at each stage. These systems are time-worn, time-tested, and provide high reliability, but cannot be practically deployed in deviated wellbores (commonly referred to as ‘horizontal wells’), due to the inability of a series of rigid interconnected rods to move linearly around the corner or bend in a deviated wellbore without impacting the well's inner wall, causing damage and wear to both casing and the rod system. Additionally, pump-jack style lift systems provide a very uneven pressure profile and relatively low and uneven flow rate of produced fluid, resulting in lower pumping volumes and inefficiencies. These pumps are very common and form part of the common general knowledge within the field of the invention.

A known solution for delivering produced fluids from horizontal wells is using relatively flexible fluid conduits that are fluidly connected to an electrical submersible pump (ESP). Known ESPs may have a variety of externally connected fluid conduits and electrical conductors in order to deliver fluids and electrical command signals to where they must be delivered for proper function.

Without being bound by any particular theory, the embodiments of the present disclosure relate to a pumping assembly that has all related fluid conduits fluidly communicate to the associated sub-assemblies in line with a longitudinal axis of the assembly. The fluid conduits are positioned internal to an outer surface of the pumping assembly. Furthermore, the embodiments of the present disclosure provide internalized electrical conductors that enter one end of the pumping assembly and extend substantially along the longitudinal axis of the pumping assembly in order to deliver (and receive) electrical signals to a power assembly at the downhole end of the pumping assembly. The inline and internal fluid conduits and the internal electrical conductors allow the outer surface of the pumping assembly to have a substantially constant outer diameter along its length and to have a substantially smooth external profile. Without being bound by any particular theory, the substantially constant outer diameter and the smooth external profile may allow the pumping assembly to have a smaller cross-sectional area so that it can be used in smaller wellbores that known pumps may not fit into.

Some embodiments of the present disclosure relate to a downhole pumping assembly. The pumping assembly including a first end and a second end defining an outer surface therebetween, the outer surface having a substantially constant outer diameter. The pumping assembly further including a power assembly proximal the second end and configured to direct a power fluid and a production fluid assembly proximal the first end and configured to receive wellbore fluids and comprising a production piston configured to direct the received wellbore fluids towards the first end. The pumping assembly also including a powered actuation assembly positioned adjacent the power assembly and in fluid communication therewith, the power actuation assembly is operatively coupled to the production fluid assembly, the powered actuation assembly configured to receive the power fluid and to move the production piston via the operative coupling for directing the received wellbore fluids towards the first end; and a central conduit that extends from the first end to the power assembly for conducting the power fluid therebetween.

Some embodiments of the present disclosure relate to a connector, also referred to herein as a flow distributor. The connector having a first end that is connectible to a fluid conducting system and a second end that is connectible to a pumping assembly. The connector also includes an inner fluid channel that is in fluid communication with a first fluid conduit, a second fluid conduit and a third fluid conduit. The inner fluid channel conducts the fluid contents of the first fluid conduit to exit the second end in a substantially centralized position, relative to the body of the connector. The connector is also configured to provide one or more internal conductor channels to allow one or more electrical conductors to extend therethrough.

Some embodiments of the present disclosure relate to a system that comprises a subsurface fluid conducting system for directing a power fluid to a connector and for directing an exhaust fluid from the connector to a surface. The system further comprises the connector for directing the power fluid, the exhaust fluid and a production fluid therethrough. The system further comprises a pumping assembly that is fluidly connectible at a first end to the connector. The pumping assembly includes a power assembly at an opposite end to the first end and a powered actuator assembly. The powered actuator assembly is in fluid communication with the power assembly for moving a powered piston of the powered actuator assembly. The Pumping assembly also includes a production fluid piston that is operatively linked to the powered piston. The pumping assembly further including a central conduit that extends from the first end to the power assembly, the central bore is configured to receive a power fluid from the fluid conducting system for conducting same to the power assembly.

In some embodiments of the present disclosure, the fluid conducting system is configured to house one or more electrical conductors that are extendible from the surface to the connector. In some embodiments of the system, the fluid conducting system comprises a conduit for conducting production fluids received from the connector to a wellhead above. The fluid conducting system also comprises a set of two conduits, one positioned within the other, the set of two conduits is configured to be fluidly connectible with the central conduit of the pumping assembly. The set of two conduits are further configured for delivering a power fluid to the central conduit and for receiving an exhaust fluid from the central conduit. In these embodiments, the connector defines an inner fluid flow channel system that is configured to direct the appropriate fluid from the pumping assembly to the appropriate fluid conduit of the fluid conducting system.

In some embodiments of the present disclosure, the fluid conducting system comprises three fluid conduits, with a first conduit positioned in a second conduit and the second conduit positioned within a third conduit. One of the three conduits is configured for delivering a power fluid from surface to the connector. Another of the three conduits is configured for delivering an exhaust fluid from the connector to the surface above. Another of the three conduits is configured for delivering a production fluid from the connector to the surface above. In these embodiments, the connector defines an inner fluid flow channel system that is configured to direct the appropriate fluid from the pumping assembly to the appropriate fluid conduit of the fluid conducting system.

In some embodiments of the present disclosure, the fluid conducting system comprises two sets of fluid conduits, with each set having a first conduit positioned in a second conduit. The outer conduit of each set may deliver a production fluid from the connector to the surface. The inner conduit of one set may deliver a power fluid from the surface to the connector and the inner conduit of the other set may deliver an exhaust fluid from the connector to the surface. In these embodiments, the connector defines an inner fluid flow channel system that is configured to direct the appropriate fluid from the pumping assembly to the appropriate fluid conduit of the fluid conducting system.

In some embodiments of the present disclosure, the fluid conducting system comprises two fluid conduits, one positioned inside the other. The inner fluid conduit is configured to deliver a power fluid from the surface to the connector and the outer conduit is configured to deliver an exhaust fluid from the connector to the surface. In these embodiments, the connector defines an inner fluid flow channel system that is configured to direct the appropriate fluid from the pumping assembly to the appropriate fluid conduit of the fluid conducting system. In these embodiments, the connector is configured to sealing engage the inner surface of a wellbore so that a production fluid can be conducted to the surface by the wellbore.

Some embodiments of the present disclosure relate to a fluid conducting system for providing fluid communication between an above-ground system of equipment and a downhole pumping assembly. The fluid connecting system comprises: a first end and a second end defining an outer surface therebetween, the first end connectible to the above-ground system of equipment; one or more internal fluid conduits for providing fluid communicate on between the first end and the second end; and a connector connected to the second end for operatively coupling the one or more internal fluid conduits to the downhole pumping assembly, the connector comprising a central channel, a secondary channel and a production fluid channel.

Some embodiments of the present disclosure relate to a downhole pumping assembly. The assembly comprising: a first end and a second end defining an outer surface therebetween, the outer surface having a substantially constant outer diameter; a power assembly proximal the second end and configured to direct a power fluid; a production fluid assembly proximal the first end and configured to receive wellbore fluids and comprising a production piston configured to direct the received wellbore fluids towards the first end; a powered actuation assembly positioned adjacent the power assembly and in fluid communication therewith, the power actuation assembly is operatively coupled to the production fluid assembly, the powered actuation assembly configured to receive the power fluid and to move the production piston via the operative coupling for directing the received wellbore fluids towards the first end, wherein the power assembly comprises a switchable valve for directing the power fluid to a first face or a second face of a powered piston of the powered actuation assembly and comprising a check valve that is typically closed during normal operations of the pumping assembly but can be opened when the downhole pump stops operations and/or by a reversed fluid flow. In some embodiments of the present disclosure, the checker valve may be actuatable between a first position and a second position, when in the first position the checker valve is closed, when in the second position the checker valve may be opened by the power fluid for reversing a direction of power fluid flow through the power assembly or a stoppage in operations of the power assembly and, therefore, the pumping assembly.

Some embodiments of the present disclosure relate to a methodfor reversing a direction of fluid flow through a system. The methodmay be used by the various systems described herein above, such as systems that that operate a pumping system. The methodcomprises the steps of: establishingflow of a first fluid in a first direction between a source of a first fluid to a power assembly, wherein the power assembly distributes the first fluid for operating a pumping system; establishingflow of a second fluid in a second direction that is opposite to the first direction between the power assembly and the source of a second fluid, wherein the second fluid is a lower pressure than the first fluid; and, reversingthe flow of the first direction to the second direction.

In some embodiments of the present disclosure, the fluid conducting system comprises three separate fluid conduits, one for conducting a power fluid to the connector, one for conducting an exhaust fluid from the connector to surface and the other for conducting a production fluid from the connector to the surface.

Without being bound by any particular theory, the fluid conducting systems described herein allow for assembly of the various conduits in the appropriate relative arrangements prior to deploying at the wellsite. This may allow for cost savings and time savings at the wellsite.

Without being bound by any particular theory, the systems and methods described herein that contemplate reversing a flow direction of the hydraulic fluid may allow for a substantially continuous or continuous flow of hydraulic fluid through the power assembly of the downhole pumping assembly. This substantially continuous or continuous flow may protect the hydraulic and electronic components of the downhole pumping system by keeping the temperature of these components within their operational temperature limits.

Unless defined otherwise, all technical and scientific terms used herein have the meanings that would be commonly understood by one of skill in the art, in the context of the present disclosure. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described. Any publications mentioned herein are incorporated herein by reference in their entirety.

The embodiments of the present disclosure relate to downhole and, therefore, submersible pumping systems for delivering produced fluids within a wellbore from a subsurface region to above-ground equipment. The embodiments of the present disclosure relate to a pumping system with a pumping assembly that includes an outer housing and that is designed to house all functional components and conducting components of the pumping assembly. Without being bound by any particular theory, the housing of the functional components and conducting components of the pumping assembly allow the outer surface of the outer housing to have a smaller outer diameter than other downhole pumping assemblies. The housing of the functional components and conducting components of the pumping assembly may also permit the outer housing to have a substantially constant outer profile. The small outer diameter and/or the substantially constant outer profile may allow the pumping system to be used in wellbores that have inner diameters of about 5.5 inches (one inch is about 2.54 cm) or greater.

is a non-limiting schematic of a pumping systemaccording to the embodiments of the present disclosure. The systemincludes an above-ground systemof equipment and a subsurface systemof equipment. The above-ground systemcomprises a hydraulic stationand a controller system. The hydraulic stationincludes a hydraulic tankfor housing volume of hydraulic fluid. A primary hydraulic displacement pumpis in fluid communication with the tankfor drawing and pressurizing the hydraulic fluidinto a power fluid, which may flow through a first flow control meterand/or a second flow control meterbefore entering a power conduit. The power conduitcontains the pressurized power fluidthat is capable of powering one or more components of the subsurface system. The hydraulic stationmay receive a return conduitthat contains a low pressure, exhaust fluidthat has returned from the subsurface system. The return conduitis in fluid communication with the tankand the exhaust fluid may pass through a hydraulic fluid cooling apparatusand/or a filterbefore entering the tank.

The controller systemmay be operatively connected to one or more components of the hydraulic station. For example, the controllermay comprise a computerized programmable logic controller (PLC). The PLCmay include a display and a flow meter moduleA for flow control of the power fluidby controlling flow control meter. The PLCmay also include a pressure control system (P/T)A that is configured to control the pressure of power fluidvia controlling activity of the primary hydraulic displacement pump. The PLCmay also include a temperature control system (T/T)for controlling the temperature of the fluidwithin the tankvia one or more temperature sensors and heating elements (not shown). The tankmay also act to cool the hot, low pressure exhaust hydraulic fluid that is received from the subsurface systemof equipment. While the heating features of the tankis necessary when the systemis located in a cold climate, the cooling features of the tankis applicable when the systemis being used to produce production fluids from a subsurface reservoir that was exposed to high temperatures to decrease the viscosity of the production fluids. For example, the subsurface reservoir may be heated by being subjected to one or more thermal mobilization procedures, such as a high-temperature steam assisted gravity drainage (SAGD) operation, a high temperature solvent operation, a downhole combustion operation, combinations thereof and the like. The PLCmay further include a variable frequency drive (VFD)A that controls the activity of the primary hydraulic displacement pumpand a further VFDA that controls the cooling apparatus.

The PLCmay also include one or more solenoid controllersA andB and one or more limit switch controllersA andA. Commands, in the form of electrical signals, from the controllersA,A,A andA can be transmitted to the subsurface equipment via an electrical conducting system. As will be appreciated by those skilled in the art, the electrical conducting systemmay be protected from the harsh environment present within the wellbore so as to provide efficient communication of commands from the controllersA,A,A andA to the subsurface equipment.

The PLCmay be configured to coordinate the delivery of power fluidvia conduit—at a desired pressure and temperature—and the movement of one or more components of the subsurface equipmentvia the controllersA,B,A andA. As will be appreciated by those skilled in the art, the PLCmay be pre-programmed to perform this coordination and/or it may respond to commands entered by a user.

The above-ground systemmay further include a wellhead systemthat includes a wellheadthat is configured to receive the conduitsand, the conductors of the electrical conducting systemand a production fluid outlet. The wellhead systemis further configured, among other functions, to provide pressure control of fluids within a wellboreof the subsurface system. The wellboremay be lined, cased, cemented or not and the wellboreis configured to receive produced fluids, for example as a multiphase flow of solids, gas and liquids, from a subsurface reservoir proximal thereto. The reservoir may be stimulated by hydraulic fracturing, thermal stimulation (such as cyclic steam cycling, steam assisted gravity drainage, heated solvent stimulation), chemically stimulated (such as solvent stimulation) and the like.

The subsurface systemmay include a pump assemblyand a fluid conducing systemthat extends from the pump assemblyto the wellhead. The fluid conducting systemprovides one or more conduits conducting the power fluidfrom conduitto the pump assemblyand the exhaust fluidfrom the pump assemblyto the conduit. In some embodiments of the present disclosure, the fluid conducting systemmay also provide an optional production conduitfor conducting production fluids to the production fluid outlet. In some embodiments of the present disclosure, the fluid conducting systemmay also provide a conduit for the electrical conducting systemto extend from the wellheadto the pumping assembly.

The pumping assemblyis configured to be positioned within an oil and/or gas well and to receive production fluids. The pumping assemblyis configured to pressurize and deliver the received production fluids (shown as unpressurized received production fluidsand pressurized received production fluidin) to the production fluid outletof the wellhead system. The pumping assemblyhas a first endA and a second endB for defining a longitudinal axis (represented by line α in) of the pumping assembly. As will be appreciated by those skilled in the art, the first endA is closer to the wellheadand, therefore, it may also be referred to as an uphole end. The second endB is further from the wellheadand, therefore, it may also be referred to as the downhole end. The term “uphole” may be used herein to refer to an end of a component or a directional orientation within the well that is towards the wellhead. The term “downhole” may be used herein to refer to a component or a directional orientation within the well that is away from the wellhead.

In some embodiments of the present disclosure, the pumping assemblycomprises three primary components: a power assembly, a powered actuator assemblyand a production fluid assembly. The pumping assemblyfurther includes a central conduitthat extends from the first endA through the production fluid assemblyand the powered actuator assemblyto the power assembly. The central conduitmay be centrally located within the cross-sectional area of the pumping assembly, or in some embodiments it may be positioned non-centrally. The central conduitis configured to provide fluid communication between the downhole end of the fluid conducting system, via a connector(which is also referred to as a flow distributor), and the power assembly.

The power assemblyis configured to receive the power fluidfrom the conduit, via the central conduit. The power assembly is further configured to direct the power fluidto the powered actuator assemblyfor moving a powered pistontherein. The powered pistonis operatively coupled by a linking member(see) to a production pistonso that if the powered pistonmoves in a first direction, the production pistonwill move in the same direction and the same stroke distance. If the powered pistonmoves in a second, opposite direction, the production pistonwill also move in the second direction and distance the same stroke distance as the powered pistonmoved.

As will be discussed further below, the pumping assemblymay also include a connectorthat is connectible to the first endA of the pumping assemblyfor providing fluid communication between the downhole end of the fluid conducting systemand the central conduit. The connectormay also be referred to as a flow distributor. In some embodiments of the present disclosure, the connectormay also provide a channel for the conductors of the electrical conducting systemto enter inside the pumping assembly. In these embodiments, all fluid/conduits that deliver fluids to and from the pumping assemblyand all electrical conductors that deliver electrical signals to—and optionally from—the pumping assemblyare inside an outer surfaceA of the pumping assembly. In some embodiments of the present disclosure, the primary components of the pumping assembly, namely: the power assembly, the powered actuator assemblyand the production fluid assemblyare all housed within an outer housing of the pumping assembly, and the outer housing defines the outer surfaceC. In other embodiments, each of the power assembly, the powered actuator assemblyand the production fluid assemblydefine their own respective outer surface such that when these assemblies are all assembled together into the pumping assemblytogether they define the outer surfaceC.

Without being bound by any particular theory, the internalization of all fluid conduits, electrical conduits and all other components of the pumping assemblywithin the outer surfaceC provides a substantially constant external profile of the pumping assembly. Furthermore, this internalized design allows the pumping assemblyto be constructed with an external diameter that may be smaller than other known submersible, downhole pumping systems. In some embodiments of the present disclosure, the outer diameter of the pumping assemblymay be substantially constant along its length from the first endA to the second endB. In some embodiments of the present disclosure, the external diameter of the pumping assemblymay be configured such that the outer surfaceC is substantially free of any protrusions so that that profile of the pumping assemblymay be referred to as a “smooth profile”.

provides a non-limiting schematic of function and fluid flows within the pumping assemblyduring operation thereof.

The power assemblycomprises an outer wall, which may form part of the outer housing of the pumping assembly, or not, but the outer wallcontributes towards defining at least part of the outer surfaceC. The outer walldefines an internal plenumthat acts a reservoir to hold lower pressure, exhaust fluid. The internal plenumalso houses a switchable valve.

Hydraulic power is provided to the pumping assemblyby delivery of the pressurized power fluidfrom the surface, via conduitand the fluid conducting systemto the central conduit. The power fluidflows through the length of the pumping assemblyto the power assembly, where it is directed to a first faceA or a second faceB of the powered piston. Lower pressure, exhaust fluidreturn to the internal plenumfrom where it enters the central conduitfor return to the exhaust conduit, via the fluid conducting system, and to the hydraulic station. In summary, the power fluidflows in a closed loop system to and from the surface to the pumping assemblyvia conduit, then through the fluid conducting system, then through the central conduitto the valve. Movement of the valvebetween its operational positions, will direct the power fluidto either the first faceA or the second faceB of the powered piston. Power fluidis directed from the opposite face of the powered pistonthat the power fluidis acting upon to flow through the valvefor return via the central conduitas described above. Being in a closed system, the power fluidmay be inside the powered actuator assemblyat pressures that are higher than ambient wellbore pressures, which may assist in lubricating and establishing a pressure isolation effect to keep wellbore fluid and contaminants from the moving parts of the powered actuator assembly. In some embodiments of the present disclosure, the pressure of the power fluidwithin the powered actuator assemblymay be at least double the ambient wellbore pressures.

As shown in, the central conduitincludes an inner conduitthat is coaxial with and extends the length of the central conduit. The inner conduitis configured to receive the power fluidfrom the fluid conducting systemand conduct the power fluidto the valve. Between the wall of the central conduitand the inner conduitis an annular space that is configured to receive the power fluidfrom the inner plenumof the power assemblyand conduct the power fluidto the exhaust conduitvia the fluid conducting system. As will be appreciated by those skilled in the art, the power fluidis a higher pressure than the power fluid, so from a materials and safety perspective, it may be desirable to use the inner conduitconducting the power fluid. However, it is contemplated by the present disclosure, that the inner conduitmay be used to conduct the power fluidand the annular space may be used to conduct the power fluid.

The powered actuator assemblymay be housed within an outer housing of the pumping assemblyor it may include an outer wall. In the latter case, the outer wallcontributes towards defining the outer surfaceC of the pumping assembly. An annular fluid chamber is defined between the outer wall(or the outer housing as the case may be) and a cylinder, which in turn houses the powered piston. The cylinderhas a first endA and a second endA, the second endB proximal to and in fluid communication with the power assembly(see). The powered piston is configured to slidably move along an inner surface of the cylinderin a first direction towards one end of the cylinderand in a second, opposite direction towards the other end of the cylinder. Suitable sealsmay be positioned between the outer edge of the powered pistonand the inner surface of the cylinderto ensure no fluid communication occurs across the powered piston and, optionally, to facilitate the sliding movement of the powered piston.

The valvemay be an electromechanical switching valve that is configured to receive the power fluidfrom the central conduitvia one or more extension conduitsA to direct the flow of the power fluidto either the first faceA or the second faceB of the powered pistonto cause the pistonto move (stroke) in a first direction or a second, opposite direction, or to bypass the powered actuator assemblyand merely flow through the valve and complete a circuit back to surface. The three valve positions may be referred to as “direct flow”, “cross-over flow” and “bypass” or “idle”. The “bypass” valve position isolates the actuator from hydraulic fluid flow and causes the pistonto be braked or locked in its then-current position, which is useful to avoid problems when tripping the downhole component into or out of the wellbore where pressure changes will come into play as the pumping assemblyis moved uphole or downhole in the well.

Additionally, while in the “bypass” or “idle” position, flow of the hydraulic fluid from surface to the pumping assemblyand back becomes relatively unimpeded, permitting fast round-tripping of fresh hydraulic fluid (for example, about 1 ½ minute per 1,000 feet travel distance) permitting use of the hydraulic fluid as a coolant to cool the pumping assembly, including the valve, as desired.

As shown in, the power fluidis directed by the valvealong conduitB to enter the powered assemblyto act upon the second faceB of the powered piston. Because the powered pistonhas the first faceA and the second faceB and it may move based upon power fluidacting upon either of these faces, the powered pistonmay be referred to as a dual-acting piston. The powered pistonand the cylinderand both of which are configured to accommodate the extension of the central conduittherethrough. When the valveis in the position depicted in, the power fluidwithin a first chamber of the cylindermay be present within the cylinderon the second faceB side of the powered piston. As the power fluidacts upon the second faceB, the exhaust fluidis directed from within the cylinderinto the annular fluid space to return to the valvevia conduitB. From the valve, the power fluidenters the inner plenumfor return to the surface as described above. In the configuration of, the powered pistoncan be said to be moving in a first direction, in this case an uphole direction.

As shown in, the power fluidis directed by the valveto enter conduitB and move through the annular fluid space to then enter the cylinderto act upon the first faceA of the powered piston. The fluid on the opposite side of the powered pistonhas lost its pressure, due to the valveopening an exhaust port. As the powered pistonmoves in the second direction, in this case the downhole direction, the power fluidis directed along conduitA to the valvefor entry into the inner plenumand return to surface as describe above.

The powered pistonis mechanically coupled, or linked, to a production pistonthat is a component of the production fluid assembly. The mechanical coupling may be effected by a sleevethat is fixed at one end to the powered pistonand fixed at the other end to the production piston. The sleevecan be cylindrical in shape in order to accommodate the central conduitaround which the sleeveis positioned. The sleevemay slide along the outer surface of the central conduitor there may be a gap therebetween. In operation, when the powered pistonmoves in a first direction, for example uphole-due to the position of the valve-the production pistonwill move in the same direction and for the same distance, which may also be referred to as stroke length or stroke distance.

The production fluid assemblyincludes an outer wall, which similar to the power assemblyand the powered actuator assembly, may form part of an outer housing of the pumping assemblyor it may be a discrete structure that together with the outer walls of the power assemblyand the powered actuator assemblydefine the outer surfaceC of the pumping assembly.

The production fluid assemblyalso includes a cylinder, within which the production pistonslidably moves in two directions. The cylinderhas a first endA that defines the first endA and a second endB that is proximal the power actuation assembly(see). As will be appreciated by those skilled in the art, the production fluid assemblyis configured to include various seals in order to perform the functions described herein. The production pistonmay, similar to the powered piston, be a dual-acting piston with a first faceA and a second faceB. The cylinderand the pistondefine two pumping chambers. A first fluid pumping chamberis defined between the first faceA and the first endA and a second fluid pumping chamberis defined between the second faceB and the second endB. As the production fluid pistonmoves, due to the operative linkage with the powered piston, the volume within the two chambers,will change, with one increasing and the other decreasing in volume and, thereby having an inverse change in pressure. For example,depicts the scenario where the valveis directing power fluidinto the powered actuator assemblyso that the powered pistonmoves in an uphole direction. Due to the sleeve, the production fluid pistonalso moves in the uphole direction, causing the volume of the first chamberto decrease and the pressure therein to increase. In the second chamber, the volume is increasing and the pressure is decreasing as the production fluid pistonmoves in the uphole direction. The opposite occurs when the valvechanges position to direct power fluidinto the powered actuator assembly, namely the volume of the first chamberincreases and the pressure therein decreases and the volume in the second chamberincreases and the pressure therein decreases.

The outer wallincludes at least two groups of ports,A and two groups of valves,that provide fluid communication between outside of the outer wallof the pumping assemblyand inside the cylinder. For example, portA (see) may provide fluid communication between outside the pumping assemblyand the first faceA of the production piston. Port(see) may provide fluid communication between outside the pumping assemblyand the second faceB of the production piston. When the pumping assemblyis positioned within a well, the pumping assemblywill be submerged within various fluids, including production fluids and ports,A may provide production fluids to be received within either of the chambers,of the cylinder. Whether or not these fluid communication flow paths are open or closed depend upon the operational position of a valve assembly made up of valves,,andand the respective pressures within the chambers,that each valve controls fluidic access to. Valvecontrols fluid communication between the second chamberand portA for regulating the flow of production fluids through portA. Valvecontrols fluid communication between the second chamberand an annular fluid chamberthat is defined between the outer walland the cylinder. Valveis configured for regulating the flow of a pressurized and received production fluid into the annular fluid chamberfrom where the fluid flows through the first endA, through the connectorand into the fluid conducting system. The annular fluid chamberextends between the first end and the second end of the production fluid assembly. Valvecontrols fluid communication between the annular fluid chamberand the connector. Valvecontrols fluid communication between the first chamberand the connector.

shows two dotted lines A and B, line A indicates a cross- sectional cut through the valve assembly at the first endA of the production fluid assembly. Line B indicates a cross-sectional cut through the valve assembly at the second endB of the assembly. Together, lines A and B are taken to represent when the valveis directing power fluidto move the pistonsanduphole.shows two further dotted lines C and D, line C indicates a cross-sectional cut through the valve assembly at the first endA and line D indicates a cross-sectional cut through the second endB. Together lines B and C are taken to represent when the valve is directing power fluidto move the pistonsanddownhole.

shows a cross-sectional view of line A and line B. Under line A, the outer surface is shown as the outer wall, as described herein above, this represents the outer surfaceC of the pumping assembly. Between the outer walland the outer surface of the cylinder(not shown in this view) is the annular fluid chamber. Facing the viewer is a valve seatthat may define at least a portion of the first endA of the cylinder. In the center is the central conduitwith the inner conduittherein. Whileshows the operational position of three sets of valvesandand three sets of valvesand, there may be more or less of these valves. Under line B, the outer walland the annular fluid chamberare shown, as is a valve seatthat may define at least a portion of the second endB of the cylinder. Invalvesandare shaded to indicate that they are in a closed operational position to prevent fluid communication thereacross. Valvesandare shown unshaded to indicate that they are in an open operational position, permitting fluid to flow thereacross.shows the same structures as, except valvesandare closed and valvesandare open. The valves of the valve assembly may be one-way checker valves, such as a floating ball-type valve where the position of the valve (open or closed) is determined by a differential pressure across the valve. For example, the open/closed position of the valves inis determined by the pressure within the fluid pumping chambers,, relative to the pressure on the opposite side of each valve.

For example, when the valvecauses the pistons,to move in the uphole direction (as in) the pressure within the second chamberis lower than, and may continue to decrease, the ambient pressure of the production fluid that surrounds the pumping assembly. This causes valveto open so that production fluids can be received within the chamber, via portA. At the same time, the pressure within the annular fluid chamberexceeds the pressure within the chamberand this causes the valveto be closed. As the pistons,move in the uphole direction, pressure within the first chamberincreases and will exceed the pressure of the ambient production fluids, this causes valveto be closed and reservoir fluids are not received within the chamber. The pressure within chamberalso causes valveto open allowing the received (and pressurized) production fluid therein to flow out of the production fluid assemblyand into the connector. In effect,depicts an operational position of the valve assembly whereby production fluids are drawn into the chamberand received production fluids within chamberare pumped out into the connector.

depicts an operational position of the valve assembly, wherein valvesandare closed and valvesandare open. This operational position directs the received production fluid within chamberto flow through the annular fluid chamberand into the connectorand to close off fluid communication between the chamberand outside the production fluid assembly. This operational position also allows new production fluids to be received, via port, into the chamber.

shows the pumping assemblycomprising the connectorpositioned within the wellboreand submerged within production fluids (depicted as open arrows). The operational position of the valve assembly of the production fluid assemblyis the same as shown inand, so that production fluids may be received within the chamberof the production fluid assemblyvia portA. Connectorcomprises a first end′ that is operatively coupled to the downhole end of the fluid conducting systemand a second end″ that is operatively coupled to the first endA of the pumping system. The connectoris configured to provide fluid communication between the downhole end of the fluid conducting systemand the central bore a channel for receiving and internalizing the electrical conducting system. While the connectoris shown inas having a larger outer diameter than the outer surfaceC of the pumping assembly, that is simply to assist with depicting the features and functionality of the connector. In fact, the connectorhas the same or smaller outer diameter than the outer surfaceC. The connectoris configured to be operatively coupled to the first endA of the pumping assembly. In particular, the connectorprovides one or more internal conduits for conducting pressurized and received production fluids received from the production fluid assemblyas described above. The fluid conducting systemcomprises a production linefor conducting the pressurized and received production fluidfrom the connectorup to the wellhead. The fluid conducting systemfurther comprises a hydraulic conduction linethat provides an extension of the conduitsand(see). In particular, lineis configured to house an extensionA of the conduitpositioned within the conduit, optionally concentrically positioned within conduitso that the power fluidflows internal to and in an opposite direction as the exhaust fluidthrough the fluid conducting system. The lineis configured to fluidly and sealingly connect with a string adapterof the connectorto receive and maintain the isolation and flow direction of the power fluidand the exhaust fluidthrough to an internal fluid channel systemof the connectorand to conduct same to fluidily communicate with the central conduit(see). In particular, the power fluidwithin conduitof lineis conducted through the internal fluid channel systemof the string adapter, through the connectorand into the inner conduit. The exhaust fluidflows through the annular space of the central conduit, through the internal fluid channel systemwithin the connectorto enter the extensionA for conduction to the surface. Whileshows the internal fluid channel systemas having a corner, the person skilled in the art will appreciate that it may be advantageous to have all corners rounded, smoothed or substantially straightened to reduce, mitigate or remove any negative impact such changes in direction could have on maintaining the pressure of the power fluid.

The connectorfurther comprises a production string adapterfor fluidly and sealingly connecting the production conduitto the connectorto facilitate conducting the pressurized and received production fluidfrom the production fluid assembly. The connector further comprises a central channelF and a secondary channelF. The central channelF can fluidly couple the power conduitwith the inner conduitof the pumping assembly. The secondary channelF can fluidly couple the exhaust conduitwith the exhaust output flow of the downhole pumping assembly.

The connectorfurther comprises an internal channel for conducting the electrical conductors of the electrical conducting systemtherethrough. This internal channel for electrical conductors is configured to receive the electrical conductors from outside the fluid conducting systemand to internalize the electrical conductors so that they may extend from the connector, through an internal channel of the pumping assembleto electrically communicate electrical signals from the controllerto the valve.