A pumping method can include displacing a rod string with pressure applied to an actuator by a pressure source including an accumulator and a separate gas volume in communication with the accumulator. A sensor indicates whether a fluid is in the gas volume. A pumping system can include an actuator, a pump connected between the actuator and an accumulator, a hydraulic fluid contacting a gas in the accumulator, a separate gas volume in communication with the accumulator, and a sensor that detects the hydraulic fluid in the gas volume. Another pumping system can include an actuator, a pump connected between the actuator and an accumulator that receives nitrogen gas from a nitrogen concentrator assembly while a hydraulic fluid flows between the pump and the actuator, a separate gas volume in communication with the accumulator, and a sensor that detects a presence of the hydraulic fluid in the gas volume.

A casing adapter and related systems and methods are provided for a lubricate and bleed operation in a wellbore where heavy fluids are directly deposited downwell. The casing adapter allows a hose to be positioned downwell and to be operably connected to a tank of heavy fluid. Once the heavy fluid is deposited, the casing adapter receives lighter fluids from the well bore, and the casing adapter is operably connected to a return tank that stores lighter fluids.

A casing adapter and related systems and methods are provided for a lubricate and bleed operation in a wellbore where heavy fluids are directly deposited downwell. The casing adapter allows a hose to be positioned downwell and to be operably connected to a tank of heavy fluid. Once the heavy fluid is deposited, the casing adapter receives lighter fluids from the well bore, and the casing adapter is operably connected to a return tank that stores lighter fluids.

A hydraulic oil well pumping system is provided. The system uses a pump to exert hydraulic pressure against a reciprocating piston over a wellbore. The piston is connected to a rod string and downhole pump for pumping oil from a wellbore. The system includes an electronic control system that controls movement of the piston as it moves between the upper and lower rod positions by cycling the hydraulic system between (i) an upstroke condition wherein the pump is pumping oil through the oil line into the hydraulic cylinder to move the piston to its upper rod position, and (ii) a neutral condition wherein the pump is no longer pumping oil into the hydraulic cylinder, but is allowing oil to flow back through the oil line in response to gravitational fall of the piston. The control system is programmed to cycle based upon a volumetric calculation of hydraulic oil in the cylinder without reference to position sensors along the wellhead. Wellhead conditions or placement of the hydraulic cylinder inside the wellbore may prohibit attaching physical sensors at the wellhead. A method for pumping oil from a wellbore using such a system is also provided herein.

A hydraulic oil well pumping system is provided. The system uses a pump to exert hydraulic pressure against a reciprocating piston over a wellbore. The piston is connected to a rod string and downhole pump for pumping oil from a wellbore. The system includes an electronic control system that controls movement of the piston as it moves between the upper and lower rod positions by cycling the hydraulic system between (i) an upstroke condition wherein the pump is pumping oil through the oil line into the hydraulic cylinder to move the piston to its upper rod position, and (ii) a neutral condition wherein the pump is no longer pumping oil into the hydraulic cylinder, but is allowing oil to flow back through the oil line in response to gravitational fall of the piston. The control system is programmed to cycle based upon a volumetric calculation of hydraulic oil in the cylinder without reference to position sensors along the wellhead. Wellhead conditions or placement of the hydraulic cylinder inside the wellbore may prohibit attaching physical sensors at the wellhead. A method for pumping oil from a wellbore using such a system is also provided herein.

Automated systems are disclosed that enable the rapid provision of fluids to downhole isolation tools. This is achieved by automatically optimizing the use of power available downhole by providing a high flowrate when pressure demand is low and a lower flowrate when pressure demand is high. Methods are disclosed which utilize the apparatus in a bottom hole assembly during downhole operations for isolating segments of a borehole.

An apparatus includes a linear motor and a fluid pump functionally connected to the linear motor. A fluid inlet of the fluid pump is in fluid communication with a fluid source. A fluid outlet of the fluid pump in fluid communication with a well. A pressure sensor is in fluid communication with the well. A controller is functionally coupled to the linear motor and the pressure sensor, wherein the controller is configured to operate the fluid pump to maintain a selected pressure in the well.

An apparatus includes a linear motor and a fluid pump functionally connected to the linear motor. A fluid inlet of the fluid pump is in fluid communication with a fluid source. A fluid outlet of the fluid pump in fluid communication with a well. A pressure sensor is in fluid communication with the well. A controller is functionally coupled to the linear motor and the pressure sensor, wherein the controller is configured to operate the fluid pump to maintain a selected pressure in the well.

The present invention relates to a subsea multipiston pump module, a subsea multistage pump and skid, having two reciprocating pistons controlled by a control means in such a way that the pistons can be driven either in a parallel mode, where the pistons are driven in phase with each other, or in a serial mode, where the pistons are driven out of phase with each other, wherein the pistons are fluidly connected with each other by a piston connection means in such a way that in parallel mode they are fluidly connected in parallel, and in serial mode, they are fluidly connected in serial. Further, the invention relates to a method of pumping a media fluid under subsea conditions.

The present invention relates to a subsea multipiston pump module, a subsea multistage pump and skid, having two reciprocating pistons controlled by a control means in such a way that the pistons can be driven either in a parallel mode, where the pistons are driven in phase with each other, or in a serial mode, where the pistons are driven out of phase with each other, wherein the pistons are fluidly connected with each other by a piston connection means in such a way that in parallel mode they are fluidly connected in parallel, and in serial mode, they are fluidly connected in serial. Further, the invention relates to a method of pumping a media fluid under subsea conditions.