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 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. The apparatus also includes a hydraulic fluid line connected to deliver hydraulic fluid from the outlet of the hydraulic pump through the hydraulic fluid port to the cylinder for causing the piston to move through an upstroke away from the first end and toward the second end of the cylinder. The apparatus further 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. The valve is operable to prevent flow of hydraulic fluid through the valve during the upstroke and the hydraulic pump is operable to prevent flow of hydraulic fluid back into the outlet of the hydraulic pump during the downstroke.

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. The apparatus also includes a hydraulic fluid line connected to deliver hydraulic fluid from the outlet of the hydraulic pump through the hydraulic fluid port to the cylinder for causing the piston to move through an upstroke away from the first end and toward the second end of the cylinder. The apparatus further 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. The valve is operable to prevent flow of hydraulic fluid through the valve during the upstroke and the hydraulic pump is operable to prevent flow of hydraulic fluid back into the outlet of the hydraulic pump during the downstroke.

A pressure-driven metered treating chemistry dispensing pump for a laundry treating appliance having a housing having first, second and third chambers, with the first and second chambers each in fluid communication with the third chamber; a fluid inlet fluidly coupling a first fluid to the first chamber; an outlet fluidly coupled to the third chamber; a piston disposed in the housing; wherein, when the piston moves in a first direction in response to the first fluid entering the first chamber via the fluid inlet, the second chamber decreases in volume thereby ejecting at least some of the second fluid from the second chamber into the third chamber, and when the piston moves in a second direction, different from the first direction, the first chamber decreases in volume thereby ejecting at least some of the first fluid from the first chamber into the third chamber to mix the at least some of the first fluid and the at least some of the second fluid to form a mixture in the third chamber, which can be emitted through the outlet.

A pressure-driven metered treating chemistry dispensing pump for a laundry treating appliance having a housing having first, second and third chambers, with the first and second chambers each in fluid communication with the third chamber; a fluid inlet fluidly coupling a first fluid to the first chamber; an outlet fluidly coupled to the third chamber; a piston disposed in the housing; wherein, when the piston moves in a first direction in response to the first fluid entering the first chamber via the fluid inlet, the second chamber decreases in volume thereby ejecting at least some of the second fluid from the second chamber into the third chamber, and when the piston moves in a second direction, different from the first direction, the first chamber decreases in volume thereby ejecting at least some of the first fluid from the first chamber into the third chamber to mix the at least some of the first fluid and the at least some of the second fluid to form a mixture in the third chamber, which can be emitted through the outlet.

A cryogenic pump system includes a supply of liquid natural gas, a source of hydraulic fluid, a cryogenic pump, and an electronic control module. The cryogenic pump is operatively arranged with the supply of liquid natural gas and the source of hydraulic fluid. The cryogenic pump is configured to operate using the source of hydraulic fluid to compress at least some of the supply of liquid natural gas for delivery to an engine. The electronic control module is operably arranged with the cryogenic pump and configured to selectively operate the cryogenic pump. Control strategies for operating the cryogenic pump system are disclosed which have reduced power demands.

A cryogenic pump system includes a supply of liquid natural gas, a source of hydraulic fluid, a cryogenic pump, and an electronic control module. The cryogenic pump is operatively arranged with the supply of liquid natural gas and the source of hydraulic fluid. The cryogenic pump is configured to operate using the source of hydraulic fluid to compress at least some of the supply of liquid natural gas for delivery to an engine. The electronic control module is operably arranged with the cryogenic pump and configured to selectively operate the cryogenic pump. Control strategies for operating the cryogenic pump system are disclosed which have reduced power demands.

A downhole pump system for increasing production of a well includes a mechanical steam pump, a steam generator, a plurality of electrical pumps, and a cable. The mechanical steam pump is disposed within a horizontal section of the well. The electrical pumps are disposed in series within the vertical section of the well above the steam generator. The cable connects the mechanical steam pump, the steam generator, and the electrical pumps.

A downhole pump system for increasing production of a well includes a mechanical steam pump, a steam generator, a plurality of electrical pumps, and a cable. The mechanical steam pump is disposed within a horizontal section of the well. The electrical pumps are disposed in series within the vertical section of the well above the steam generator. The cable connects the mechanical steam pump, the steam generator, and the electrical pumps.

This invention relates to apparatus and methods for pumping liquids, in particular using hydraulic ram pump techniques. The techniques we describe can advantageously be used, for example, for drawing water from a deep well in a developing country. We describe a hydraulic ram liquid pump, the pump comprising: a liquid conduit having first and second arms and a connecting portion to connect said arms; first and second one-way inlet valves to said liquid conduit; first and second internal shockwave generating devices within said liquid conduit between said first and second inlets; at least one one-way exit valve from said liquid conduit; wherein, in use, when said second shockwave generating device is sealed a column of liquid in said first arm is in fluid communication with a said exit valve and when said first shockwave generating device is sealed a column of liquid in said second arm is in fluid communication with a said exit valve.