A drive fluid inlet is at an uphole end of the submersible pump top drive. A removable hydraulic motor is driven by drive fluid received by the drive fluid inlet. The removable hydraulic motor is separable from a downhole pump. A receiver is at a downhole end of the hydraulic motor. The receiver is configured to mate with the downhole pump. A drive fluid outlet is configured to expel the drive fluid after the drive fluid has flowed through the hydraulic motor. The drive fluid outlet is downhole of the drive fluid inlet.

A drive fluid inlet is at an uphole end of the submersible pump top drive. A removable hydraulic motor is driven by drive fluid received by the drive fluid inlet. The removable hydraulic motor is separable from a downhole pump. A receiver is at a downhole end of the hydraulic motor. The receiver is configured to mate with the downhole pump. A drive fluid outlet is configured to expel the drive fluid after the drive fluid has flowed through the hydraulic motor. The drive fluid outlet is downhole of the drive fluid inlet.

A linear actuator for pumping comprising a stator having an inner opening, a shaft having a plurality of permanent magnets spaced linearly in the axial direction, the shaft disposed in the stator opening and configured to reciprocate linearly in the axial direction relative to the stator, the stator comprising a first stator assembly having a plurality of pole sections spaced linearly in the axial direction and a plurality of coils disposed therebetween, a second stator assembly having a plurality of pole sections spaced linearly in the axial direction and a plurality of coils disposed therebetween, a bearing assembly positioned axially between the first stator assembly and the second stator assembly, and the bearing assembly having a width that is a function of the spacing of the plurality of pole sections of the first stator assembly and the second assembly and the spacing of the plurality of permanent magnets of the shaft.

A linear actuator for pumping comprising a stator having an inner opening, a shaft having a plurality of permanent magnets spaced linearly in the axial direction, the shaft disposed in the stator opening and configured to reciprocate linearly in the axial direction relative to the stator, the stator comprising a first stator assembly having a plurality of pole sections spaced linearly in the axial direction and a plurality of coils disposed therebetween, a second stator assembly having a plurality of pole sections spaced linearly in the axial direction and a plurality of coils disposed therebetween, a bearing assembly positioned axially between the first stator assembly and the second stator assembly, and the bearing assembly having a width that is a function of the spacing of the plurality of pole sections of the first stator assembly and the second assembly and the spacing of the plurality of permanent magnets of the shaft.

An artificial lift system for a horizontal well deploys a downhole pump and flexible bladder reservoir chamber to be used with a conventional rod pump. The rod pump is used in the vertical at the top of the curve. The flexible bladder reservoir chamber is connected to the rod pump intake. The downhole pump is set in the producing formation and is connected to the reservoir chamber by tubing. The lift system uses a compressor drive system to operate the downhole pump to move fluids from the producing formation to the reservoir chamber. The reservoir chamber uses the flexible chamber bladder that is filled with well fluids by operation of the downhole pump to provide a continuous supply of well fluids to the rod pump intake. Operation of the rod pump lifts fluids from the flexible chamber bladder without regard to the operation state of the downhole pump.

An artificial lift system for a horizontal well deploys a downhole pump and flexible bladder reservoir chamber to be used with a conventional rod pump. The rod pump is used in the vertical at the top of the curve. The flexible bladder reservoir chamber is connected to the rod pump intake. The downhole pump is set in the producing formation and is connected to the reservoir chamber by tubing. The lift system uses a compressor drive system to operate the downhole pump to move fluids from the producing formation to the reservoir chamber. The reservoir chamber uses the flexible chamber bladder that is filled with well fluids by operation of the downhole pump to provide a continuous supply of well fluids to the rod pump intake. Operation of the rod pump lifts fluids from the flexible chamber bladder without regard to the operation state of the downhole pump.

A pump jack with counterbalance system is provided, including a supporting structure, a linear actuator with a housing and a shaft, a first pulley carried by the shaft, a second pulley fixed above the first pulley, an elongate flexible member, and a weight cared by the shaft. The housing is vertically oriented and mounted to the supporting structure above a ground surface. The shaft has a first end received within the housing and a connection end that extends out of the housing and carries the first pulley and the weight. The linear actuator drives the shaft between extended and retracted positions. The elongate member passes around the pulleys and has a first end fixed relative to the housing and a second end connected to a surface rod, such that reciprocating movement of the shaft causes the surface rod to move vertically and the weight to act as a mechanical counterbalance.

A pump jack with counterbalance system is provided, including a supporting structure, a linear actuator with a housing and a shaft, a first pulley carried by the shaft, a second pulley fixed above the first pulley, an elongate flexible member, and a weight cared by the shaft. The housing is vertically oriented and mounted to the supporting structure above a ground surface. The shaft has a first end received within the housing and a connection end that extends out of the housing and carries the first pulley and the weight. The linear actuator drives the shaft between extended and retracted positions. The elongate member passes around the pulleys and has a first end fixed relative to the housing and a second end connected to a surface rod, such that reciprocating movement of the shaft causes the surface rod to move vertically and the weight to act as a mechanical counterbalance.

A closed-loop hydraulic circuit includes a piston chamber housing a piston rod and a ram piston coupled to an end of the piston rod, and a pump in fluid communication with the piston chamber at first and second hydraulic ports. Pumping a hydraulic fluid to the first hydraulic port causes a forward stroke of the ram piston and the piston rod, and pumping the hydraulic fluid to the second hydraulic port causes a return stroke of the ram piston and the piston rod within the piston chamber. An accumulator is in fluid communication with the pump and the piston chamber, and a 3-2 valve is actuatable between a first position, where pressurized hydraulic fluid is conveyed from the accumulator to the pump during the forward stroke, and a second position, where excess hydraulic fluid is conveyed from the first hydraulic port to the accumulator during the return stroke.

A closed-loop hydraulic circuit includes a piston chamber housing a piston rod and a ram piston coupled to an end of the piston rod, and a pump in fluid communication with the piston chamber at first and second hydraulic ports. Pumping a hydraulic fluid to the first hydraulic port causes a forward stroke of the ram piston and the piston rod, and pumping the hydraulic fluid to the second hydraulic port causes a return stroke of the ram piston and the piston rod within the piston chamber. An accumulator is in fluid communication with the pump and the piston chamber, and a 3-2 valve is actuatable between a first position, where pressurized hydraulic fluid is conveyed from the accumulator to the pump during the forward stroke, and a second position, where excess hydraulic fluid is conveyed from the first hydraulic port to the accumulator during the return stroke.