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 pump jack controller is provided that can harness the potential energy generated during the operation of one pump jack amongst a plurality of pump jacks located at a well site and convert that potential energy into electrical energy that can be used to provide electrical power generated by the pump jack to power the other pump jacks located at the well site.

A pump jack controller is provided that can harness the potential energy generated during the operation of one pump jack amongst a plurality of pump jacks located at a well site and convert that potential energy into electrical energy that can be used to provide electrical power generated by the pump jack to power the other pump jacks located at the well site.

A system for energy recovery from a rod pump includes a reversible hydraulic pump; a variable speed reversible motor-generator connected to the reversible hydraulic pump; and a variable speed drive that operates the motor-generator to rotate the reversible hydraulic pump in a forward direction to pump hydraulic fluid to the rod pump during an upstroke, and to operate the motor-generator in a generator mode in which a weight of a rod string lowers a piston in the rod pump during a downstroke to pump hydraulic fluid to rotate the hydraulic pump in reverse such that the motor-generator generates electricity, and the variable speed drive modulates a speed of the motor-generator during the downstroke to modulate a speed of the reversible hydraulic pump to control a rate of flow of hydraulic fluid through the reversible hydraulic pump and thereby modulate a rate of downward motion of the rod string.

A system and method for optimizing performance of an artificial lift system are provided. The optimization process can be performed automatically by a controller configured to receive optimization parameters from the user and information regarding the performance of the system. The optimization process adjusts the pumping speed of the system in response to measured rod load and a position of the downhole pump or surface pumping unit. More particularly, the optimization process can increase or decrease the pump speed of the system in response to the measured rod load at a reference position relative to a reference rod load at the reference position. The reference load and position can be selected to indicate pump inefficiencies. For example, the target reference load and position can indicate fluid pounding if the measured rod load at the reference position is greater than the reference rod load at the reference position.

A well service pump system for supplying working fluid to a well, the pump system having structural joint coupled to and extending between the housing of a hydraulic ram cylinder and the housing of a working fluid end cylinder that maintains the distance between the housings and stabilizes the housings relative to one another without interfering with the operation of the pump system. The structural joint further permits the use of minimal supporting structures for securing the hydraulic ram cylinder and working fluid end cylinder to a surface, such as the bed of a trailer.

Various embodiments include methods and apparatus structured to pump material, where such material is difficult to pump. In an embodiment, an apparatus can include an injector device capable of self-injecting material into a high pressure line. The apparatus may include multiple valves to control recharge of material into the injector device and to control reinjection of the material into the high pressure line. In an embodiment at a well site, a portion of fluid being injected into a wellbore can be diverted from one or more high pressure pumps to an injector device, where the diverted portion of the fluid can be used to power the injector device to inject material from a mixing tank to add material to the wellbore in addition to the non-diverted portion of the fluid injected into the wellbore. Additional apparatus, systems, and methods can be implemented in a variety of applications.

Various embodiments include methods and apparatus structured to pump material, where such material is difficult to pump. In an embodiment, an apparatus can include an injector device capable of self-injecting material into a high pressure line. The apparatus may include multiple valves to control recharge of material into the injector device and to control reinjection of the material into the high pressure line. In an embodiment at a well site, a portion of fluid being injected into a wellbore can be diverted from one or more high pressure pumps to an injector device, where the diverted portion of the fluid can be used to power the injector device to inject material from a mixing tank to add material to the wellbore in addition to the non-diverted portion of the fluid injected into the wellbore. Additional apparatus, systems, and methods can be implemented in a variety of applications.

Pumps are provided, more particularly piston type pumps having increased energy efficiency, systems incorporating such piston type pumps, and methods of operating piston type pumps. The pumps are suitable for pumping of oil from an oil well or for pumping other liquids such as ground water, subterranean liquids, brackish water, sea water, waste water, cooling water, gas, coolants, and the like.