Abstract: A method of producing fluid from a wellbore includes operating a pump located proximate to a zone of fluid influx in the wellbore to draw a reservoir fluid from a reservoir into the wellbore at the zone of fluid influx. The pump is coupled to a tubing string extending above the pump, and a packer is coupled to the tubing string proximate to an upper end of the zone of fluid influx and seals an annular space around the tubing string. The method includes operating the pump to produce the reservoir fluid from the wellbore through the tubing string. A pump includes a drive chamber with a drive piston, a production chamber with a production piston coupled to the drive piston, and axially separated traveling valves.

Abstract: A hydraulic lift apparatus for operating a downhole pump features a hydraulic linear actuator with a piston longitudinally slidable on a central axis of a rotatable portion of a housing. An anti-rotation rod runs longitudinally through the piston at a position radially offset outwardly from the central axis to prevent rotation between the piston and housing. A stationary motor powers a drive train whose output is connected to the rotatable portion of the housing and centered on the central axis. The actuator is one-way actuator with a hydraulically driven upstroke. A leak detection passage extends through the piston to collect fluid that has leaked across the piston seals and convey it to a leak detection port and associated containment tank. A position sensor for monitoring the piston movement features a sensing rod depending downwardly into a hollow piston shaft carried by the piston and connected to the pump rod.

Abstract: A compression apparatus for compressing a fluid, the apparatus having a frame and a motor mounted to the frame, the improvement comprising a drive mechanism installed on the frame so as to be driven by the motor and at least one piston-cylinder unit operably connected to the drive mechanism, the piston-cylinder unit having a cylinder, a piston slidably installed within the cylinder, and a piston rod interconnecting the piston and the drive mechanism so as to shift the piston up and down within the cylinder.

Abstract: The invention relates to a hydraulic device with a supply line for pressurized hydraulic fluid and with a lubricating pump that is connected to the supply line in a fluidic fashion. The lubricating pump comprises a hydraulic inlet, a pump element for conveying a lubricant from a reservoir to at least one lubricating point of the hydraulic device, and mechanism for producing a pump stroke of the pump element. The mechanism for producing a pump stroke comprises a base body, a piston unit movable in the base body, and a reversing mechanism for reversing the direction of movement of at least one element of the piston unit.

Abstract: A linear compressor for multi-compression includes a stationary cylinder, a moving piston, and a stationary piston. The stationary cylinder has a first compression chamber formed therein. The stationary cylinder is provided at one side thereof with an outlet part. The moving piston is movable forward and backward by a linear motor, that compresses a fluid in the first compression chamber. The moving piston has a second compression chamber formed and is provided, at the position where the second compression chamber communicates with the first compression chamber, with a first valve. The stationary piston is fixedly disposed in the compressor. The stationary piston is fitted in the moving piston so that the fluid in the second compression chamber is compressed as the moving piston is reciprocated.

Abstract: A multistage piston compressor and a method for cooling of an electrical motor for a multistage piston compressor. Conventional piston compressors produce a high part of heat dissipation. This influences negatively the energy balance of the piston compressor and requires a high expenditure in cooling agents for conserving and treating with care the piston compressor. It is therefore disclosed to furnish the always present volume changeable free chamber (19) at the piston compressor (1) as a pressure chamber and a suction chamber, and to connect this volume changeable free chamber (19) to the atmosphere through the inner chamber of the electrical motor (2).

Abstract: A pump for compression of air includes a first inner stationary cylinder (1) arranged a second displaceable cylinder (2). A piston (3) arranged for reciprocating motion together with the first cylinder (1) divides the interior space of the first cylinder (1) into a first and a second chamber (8,9). A third cylinder (15) surrounding the second cylinder (2) is formed with a fourth chamber (16) in communication, via a passage (17), with a third chamber (12) in the second cylinder (2) and, via an inlet valve (19), with the surrounding atmosphere. Displacement of the piston rod (4) in one direction forces the air in the third chamber (12) into the first and second chambers (8,9) with resulting pressure increase in said chambers (8,9). At the same time, air is sucked into the fourth chamber (16). Upon displacement of the piston rod (4) in the opposite direction, the air in the fourth chamber (16) is forced into the third chamber (12) and further into the first chamber (8).

Abstract: A sucker rod pump comprises a cylindrical housing (1) having a suction valve (3), a hollow plunger (2) with a discharge valve (18) capable of reciprocating along the cylindrical housing (1) and at least two stationary sealing devices (7) spaced from each other for a distance equal to or higher than the length of the hollow plunger (2) which interacts with each sealing device (7) interacting, in turn, with the hollow plunger (2) whose length (L) is equal to or higher than the sum of the distance (H) between the adjacent sealing devices (7) and the length (B) of one sealing device (7) but less than the sum of the double distance (H) between the adjacent sealing devices (7) and the length (B) of one sealing device (7).

Abstract: This invention relates to a vacuum pump. The pump includes a pump housing (10) having upper and lower cylindrical, partly liquid filled, compression chambers (11 and 12 respectively) which are separated from each other and in which an upper and a lower part (14, 15) of a piston (12) is movable. The piston has a passage (21) which is provided with a check valve and which provides communication between the upper and the lower chamber (11 and 12 respectively). The upper chamber communicates, via an opening (26) which is provided with a check valve, with a liquid filled de-aeration receptacle (27). The lower chamber (12), during a part of the movement of the piston, via an inlet (33), communicates with the space being evacuated.

Abstract: A sub incorporating a check valve is connected into the lower end of a well pipestring. This valve will pass hot steam injected down the pipestring to the formations to loosen up the thick crude oil. The check valve prevents back flow and thus will hold the high pressure steam. To resume production, the production pump can then be lowered through the pipestring. The pump itself is provided with an extended probe member which will unseat the check valve when the pump is in proper position so that production pumping can resume.

Abstract: A rod-drawn pump for use in a well includes a tubing and a rod reciprocating within the tubing to move a plunger in a series of alternating upward strokes and downward strokes. The plunger defines a pump chamber with a standing valve through which liquid from the well passes during the upward stroke of the plunger. During the downward stroke, the liquid in the pump chamber passes through a traveling valve in the plunger and into a particular cavity defined by the plunger and a third valve. During the next upward stroke, the liquid in the particular cavity passes through the third valve to produce a column of the liquid which is eventually lifted from the well. The third valve supports the column of the liquid during the next downward stroke so that the traveling valve in the plunger is open when it contacts the surface of the liquid in the pump chamber. This inhibits gas and liquid pound during the downward stroke.

Abstract: The method and apparatus for producing an oil well, by the provision of a pumpjack unit which reciprocates an engine assembly located within the upper extremity of a wellbore. The engine assembly has a power piston which hydraulically drives a lift piston by means of hydraulic fluid being transferred therebetween. The lift piston is directly attached to and reciprocates a string of sucker rod, which in turn reciprocates the downhole production pump.The hydraulic fluid associated with the engine assembly is contained within a closed system, and the relative sizes of the power and lift pistons are of a ratio to cause the lift piston to travel a greater distance respective to the power piston, thereby enabling a relatively short stroke of the polish rod to impart the piston of the subsurface pump with a relatively larger stroke.