Abstract: A method and system are disclosed for pumping a multi-phase fluid from an oil well. The method may comprise delivering a flow of a multi-phase fluid to a multi-phase fluid pumping system, wherein the multi-phase fluid has a gas/liquid ratio that varies during operation. The multi-phase fluid pumping system is operated to increase the pressure of the multi-phase fluid that is delivered thereto. Thereafter the flow of pressurized multi-phase fluid is delivered from the multi-phase fluid pumping system to one or more discharge conduits. The pump system may have a pump fluid chamber between opposed pairs of buffer chambers and driving fluid chambers. Seals may be provided to seal the respective chambers.

Abstract: A compressor comprises a first cylinder for compressing a fluid and a second cylinder for driving a piston in the first cylinder. The first cylinder comprises a chamber with first and second ends. The piston is reciprocally movable along an axial direction of the chamber for compressing a fluid. Three or more first ports at the first end include at least one first inlet port and at least one first outlet port. Three or more second ports at the second end include at least one second inlet port and at least one second outlet port. Each port has an axial direction parallel to the axial direction of the chamber. A check valve is connected inline with each port along the axial direction of the port.

Abstract: Methods and systems are provided to adaptively control a hydraulic fluid supply to supply a driving fluid for applying a driving force on a piston in a gas compressor, the driving force being cyclically reversed between a first direction and a second direction to cause the piston to reciprocate in strokes. During a first stroke of the piston, a speed of the piston, a temperature of the driving fluid, and a load pressure applied to the piston is monitored. Reversal of the driving force after the first stroke is controlled based on the speed, load pressure, and temperature.

Abstract: Systems are provided comprising at least one driving cylinder comprising a driving chamber and a driving piston within the driving chamber. The driving piston separates the driving chamber into a driving fluid zone for receiving a driving fluid and a buffer zone for receiving a buffer fluid. The driving piston is movable in the driving chamber by the driving fluid. The systems may also comprise a driven cylinder comprising a driven chamber and a driven piston moveable in the driven chamber. The driven piston is connected to and driven by the driving piston to move within the driven chamber. The driven chamber comprises an input port configured to receive a driven fluid at a first, lower pressure into the driven chamber and an output port configured to expel the driven fluid at a second, higher pressure from the driven chamber when the driven fluid is pressurized by the driven piston.

Abstract: Methods and systems are provided to adaptively control a hydraulic fluid supply to supply a driving fluid for applying a driving force on a piston in a gas compressor, the driving force being cyclically reversed between a first direction and a second direction to cause the piston to reciprocate in strokes. During a first stroke of the piston, a speed of the piston, a temperature of the driving fluid, and a load pressure applied to the piston is monitored. Reversal of the driving force after the first stroke is controlled based on the speed, load pressure, and temperature.

Abstract: Methods and systems are provided to adaptively control a hydraulic fluid supply to supply a driving fluid for applying a driving force on a piston in a gas compressor, the driving force being cyclically reversed between a first direction and a second direction to cause the piston to reciprocate in strokes. During a first stroke of the piston, a speed of the piston, a temperature of the driving fluid, and a load pressure applied to the piston is monitored. Reversal of the driving force after the first stroke is controlled based on the speed, load pressure, and temperature.

Abstract: A lift apparatus and method for driving a downhole reciprocating pump is disclosed and includes a hydraulic cylinder having a piston and a hydraulic fluid port, the piston being coupled to a rod for driving the reciprocating pump, the piston being moveable between first and second ends of the cylinder in response to a flow of hydraulic fluid through the hydraulic fluid port. A variable displacement hydraulic pump is responsive to a displacement control signal to draw hydraulic fluid from a reservoir and to produce a controlled flow of hydraulic fluid at the outlet. The apparatus also includes a valve connected between the hydraulic fluid port and the reservoir, the valve being responsive to a valve control signal for controlling discharge of hydraulic fluid from the hydraulic fluid port of the cylinder back to the reservoir to facilitate movement of the piston through a downstroke away from the second end toward the first end of the cylinder.

Abstract: Methods and systems are provided to adaptively control a hydraulic fluid supply to supply a driving fluid for applying a driving force on a piston in a gas compressor, the driving force being cyclically reversed between a first direction and a second direction to cause the piston to reciprocate in strokes. During a first stroke of the piston, a speed of the piston, a temperature of the driving fluid, and a load pressure applied to the piston is monitored. Reversal of the driving force after the first stroke is controlled based on the speed, load pressure, and temperature.

Abstract: Methods and systems are provided to adaptively control a hydraulic fluid supply to supply a driving fluid for applying a driving force on a piston in a gas compressor, the driving force being cyclically reversed between a first direction and a second direction to cause the piston to reciprocate in strokes. During a first stroke of the piston, a speed of the piston, a temperature of the driving fluid, and a load pressure applied to the piston is monitored. Reversal of the driving force after the first stroke is controlled based on the speed, load pressure, and temperature.

Abstract: A lift apparatus and method for driving a downhole reciprocating pump is disclosed. The apparatus includes a hydraulic cylinder having a piston and a hydraulic fluid port, the piston being coupled to a rod for driving the reciprocating pump, the piston being moveable between first and second ends of the cylinder in response to a flow of hydraulic fluid through the hydraulic fluid port. The apparatus also includes a variable displacement hydraulic pump coupled to receive a substantially constant rotational drive from a prime mover for operating the hydraulic pump, the hydraulic pump having an outlet and being responsive to a displacement control signal to draw hydraulic fluid from a reservoir and to produce a controlled flow of hydraulic fluid at the outlet.