Well Pump Driven By Fluid Motor Mounted Above Ground Patents (Class 417/904)
  • Patent number: 11542799
    Abstract: 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.
    Type: Grant
    Filed: August 31, 2020
    Date of Patent: January 3, 2023
    Inventor: Micheal Neil Scott
  • Patent number: 10550673
    Abstract: 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.
    Type: Grant
    Filed: June 20, 2018
    Date of Patent: February 4, 2020
    Assignee: Hydraulic Rod Pumps, International
    Inventors: Christopher M. Hodges, Lance A. Mehegan, Timothy L. Hankerd, Nathan Terry, Walter Phillips
  • Patent number: 10184467
    Abstract: The non-beam pumping unit driven by a biaxial comprises a base, a tower body and a drive mechanism. The drive mechanism is mounted on the platform, comprising a biaxial motor, a large roller, a small roller, a belt and a counterweight device. The two ends of the biaxial motor are respectively connected with the two ends of the large roller through the chain and the sprocket respectively. The utility uses the biaxial motor instead of the uniaxial motor which in the prior art, the motor and the large roller on both sides are in balance, and solves the problem of partial grinding effectively and prolongs the service life of the bearing.
    Type: Grant
    Filed: July 24, 2017
    Date of Patent: January 22, 2019
    Assignee: Daqing Dannuo Petroleum Technology Development Co, Ltd.
    Inventor: Zhishen Su
  • Patent number: 9631463
    Abstract: An artificial lift system for use with a subterranean well can include a cylinder having a piston reciprocably disposed therein, the piston having opposing sides, one side being selectively communicable with at least one accumulator, and the other side having two areas, each of the areas being selectively communicable with a hydraulic pressure source and a hydraulic reservoir, and a gas pressure source connected to the accumulator, the gas pressure source including a gas compressor connected between at least one gas container and the accumulator. A method of controlling an artificial lift system can include connecting a cylinder to a hydraulic pressure source and to at least one accumulator, the accumulator being connected to a gas pressure source, and operating a gas compressor of the gas pressure source, thereby increasing hydraulic pressure applied to the cylinder from the accumulator.
    Type: Grant
    Filed: July 8, 2014
    Date of Patent: April 25, 2017
    Assignee: Halliburton Energy Services, Inc.
    Inventors: Tao Tao, Mathew J. McEachern, Huajun Chen, Yanmei Li
  • Patent number: 8875781
    Abstract: A pumping assembly includes a hydraulic pump having a hydraulic ram tied to a reciprocating annular piston having a central bore. When the annular piston moves in an upward direction, the hydraulic ram moves toward an extended position extending from the housing. When the annular piston moves in a downward direction, the hydraulic ram moves toward a retracted position retracted within the housing. A polish rod extends up through the central bore of the annular piston and is held in position by a polish rod clamp positioned on top of the hydraulic ram. The polish rod moves with the hydraulic ram. Other pumping systems, devices, and methods are also disclosed.
    Type: Grant
    Filed: September 2, 2013
    Date of Patent: November 4, 2014
    Assignee: 1238585 Alberta Ltd.
    Inventor: Perry L. St. Denis
  • Patent number: 8562308
    Abstract: A hydraulic cylinder assembly for a fluid pump including a cylinder, a bearing attached to an approximate first end of the cylinder, a rod slideably mounted within the bearing, and a piston located about an end of the rod in the cylinder opposite the bearing. A central axis of the rod is offset from, and parallel to, a centerline of the cylinder to impede a rotation of the piston about the rod. The hydraulic cylinder assembly further including a hydraulic pump fluidly connected to the cylinder, the pump configured to provide a hydraulic pressure to the cylinder during an up-stroke of the piston and rod and the pump further configured to generate electricity on the down-stroke of the piston and rod.
    Type: Grant
    Filed: October 11, 2011
    Date of Patent: October 22, 2013
    Assignee: Rodmax Oil & Gas, Inc.
    Inventors: David A. Krug, Stanley D. Nelsen, J. Dennis Allison
  • Patent number: 8534364
    Abstract: An underwater placed assembly produces gas or gas and oil/condensate from a subsea gaseous reservoir, where at least one production well is provided from the seabed to a production zone and at least one water injection well is provided from the seabed to an injection zone. The assembly includes: a pressure increasing device connected to the outlet of the production well in order to increase the pressure in a production flow from the production well, and a water turbine that is connected to and driving the pressure increasing device.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: September 17, 2013
    Assignee: Statoil ASA
    Inventor: Harald Underbakke
  • Patent number: 8523543
    Abstract: A pumping assembly includes a well head with a radial flow channel for pumped fluids. A spacer stand is secured to the well head. A hydraulic pump is provided with a housing secured to the spacer stand. The hydraulic pump has a hydraulic ram tied to a reciprocating annular piston having a central bore. When the annular piston moves in an upward direction the hydraulic ram moves toward an extended position extending from the housing. When the annular piston moves in a downward direction, the hydraulic ram moves toward a retracted position retracted within the housing. A polish rod extends up through the central bore of the annular piston and is held in position by a polish rod clamp positioned on top of the hydraulic ram. The polish rod moves with the hydraulic ram.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: September 3, 2013
    Assignee: 1238585 Alberta Ltd.
    Inventor: Perry L. St. Denis
  • Patent number: 8523533
    Abstract: A hydraulic rod pumping unit (12) has a constant horsepower regenerative assist featuring downstroke energy recovery. The pumping unit (12) has a hydraulic ram (26) connected to a ram pump (18). The drive shaft (40) of the ram pump (18) is coupled to the drive shaft (38) of an accumulator pump (20) and to a rotor of a drive motor (16). A hydraulic accumulator (24) is connected to the output of the accumulator pump (20). The ram pump (18) and the accumulator pump (20) are preferably variable displacement piston pumps which are controlled by a microprocessor based controller (44), such that during the downstroke of the hydraulic ram (26) the ram pump (18) operates as an hydraulic motor powering the accumulator pump (20) and during the up stroke of the hydraulic ram (26) the accumulator pump (20) operates as a hydraulic motor to provide assist to the ram pump (18).
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: September 3, 2013
    Inventor: Larry D. Best
  • Patent number: 8360751
    Abstract: A pump has a pump barrel formed from a larger diameter section and a smaller diameter section. Each section has a biased piston moveable within the section and the pistons are connected together to form a variable volume chamber between the pistons. As the connected pistons move toward the larger diameter section, a volume of fluid is moved through an inlet valve into the variable volume chamber of increasing volume. When the pistons are moved toward the smaller diameter section, a differential volume of fluid is discharged from the variable volume chamber of decreasing volume through a discharge valve into a discharge conduit. The pistons are actuated to move within the pump barrel by application and release of pressure at a remote end of the discharge conduit.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: January 29, 2013
    Assignee: Suncor Energy Inc.
    Inventor: Grant Duncan
  • Patent number: 8322435
    Abstract: A pressure driven pumping system includes a piston disposed within a first bore of a housing to separate a process chamber from a working chamber. A rod member coupled to the separating member extends into a reduced pressure chamber. The piston has a first face exposed to the process chamber and a second face exposed to the working chamber. The second face has an effective area less than an effective area of the first face. The housing may be placed in seawater at a selected depth. The process chamber can be in fluid communication with a well to pass well fluid into the process chamber at well pressure to move the piston, to discharge seawater from the seawater chamber. The working fluid, typically seawater in a subsea application, is pumped into the working chamber to move the piston, which discharges well fluid from the process chamber.
    Type: Grant
    Filed: May 5, 2010
    Date of Patent: December 4, 2012
    Assignee: Hydril USA Manufacturing LLC
    Inventors: Robert Arnold Judge, Peringandoor Raman Hariharan
  • Patent number: 8256504
    Abstract: An unlimited stroke drive method for pumping fluid from an oil well in which the well has a tubing string extending from the earth's surface down to a fluid producing formation. The method includes the steps of positioning a pump barrel within the tubing, an upper end of the pump barrel having communication through a standing valve with the interior of the tubing string, vertically reciprocating a length of flexible cable within the tubing string to vertically reciprocate a plunger within the pump barrel to allow a lower portion to quickly fill with fluid from the producing formation and then to a downward position in which fluid within the pump barrel lower portion is transferred through a traveling valve to an area within the pump barrel above the plunger to move formation fluid from within the pump barrel to the interior of the tubing and thence to the earth's surface.
    Type: Grant
    Filed: September 5, 2007
    Date of Patent: September 4, 2012
    Inventor: T. Leon Brown
  • Patent number: 8235107
    Abstract: A hydraulic oil well pumping arrangement employs a compensating type hydraulic pump, a directional valving arrangement and a proportioning valving arrangement. When the directional valve is energized, oil is directed to the rod end of the hydraulic cylinder. The rod or piston part of the hydraulic cylinder will then elevate until a first limit switch is actuated which then will de-energize the directional valve and send a current signal to the proportional valve. This current signal to the proportional valve forces it to open to a point at which the cylinder rod would extend at the desired velocity until it reaches a second limit switch. The second limit switch is near the bottom (for example, 1 foot, or 0.30 meters) of travel of the rod or piston. The current signal to the proportional valve is then decreased, creating a choking arrangement that forces the cylinder rod to decelerate. The cylinder rod then reaches another limit switch.
    Type: Grant
    Filed: July 23, 2010
    Date of Patent: August 7, 2012
    Assignee: Lufkin Industries, Inc.
    Inventors: Michael A. Fesi, Willard J. Lapeyrouse, Kenneth H. Vincent
  • Patent number: 8087904
    Abstract: A hybrid hydraulic-electric pumping unit (12) with downstroke energy recovery is disclosed which is operated in a conventional flow mode to supply hydraulic fluid to a hydraulic ram (26), and then is operated in a reverse flow mode to receive the hydraulic fluid from the hydraulic ram (26) and turn an electric motor (16) to generate electric power. A single hydraulic hose (48) connects the pump (18) to the hydraulic ram (26), and is used for both passing the hydraulic fluid from the pump (18) to the hydraulic ram (26) and from the ram (26) to the pump (18). The potential energy of the weight of sucker rods (10) lifted in operating the pumping unit (12) is recovered by operating the pump (18) and motor (16) with return of the hydraulic fluid from the hydraulic ram (26) through the pump (18), which turns the motor (16) to generate electric power.
    Type: Grant
    Filed: August 14, 2008
    Date of Patent: January 3, 2012
    Assignee: Global Oilfield Services LLC
    Inventor: Larry D. Best
  • Patent number: 8083499
    Abstract: A hydraulic cylinder assembly for a fluid pump including a cylinder, a bearing attached to an approximate first end of the cylinder, a rod slideably mounted within the bearing, and a piston located about an end of the rod in the cylinder opposite the bearing. A central axis of the rod is offset from, and parallel to, a centerline of the cylinder to impede a rotation of the piston about the rod. The hydraulic cylinder assembly further including a hydraulic pump fluidly connected to the cylinder, the pump configured to provide a hydraulic pressure to the cylinder during an up-stroke of the piston and rod and the pump further configured to generate electricity on the down-stroke of the piston and rod.
    Type: Grant
    Filed: October 10, 2006
    Date of Patent: December 27, 2011
    Assignee: QuaLift Corporation
    Inventors: David A. Krug, Stanley D. Nelsen, J. Dennis Allison
  • Patent number: 7927083
    Abstract: An apparatus and method for pumping from a well. A pump includes a piston assembly reciprocably engaged in a cylinder assembly. Pressure applied to a column of fluid above the pump causes a pump chamber to fill with fluid. A spring mechanism coupled to an anchor point above the piston assembly provides upward force on the piston assembly. Alternate cycles of the application and release of pressure result in the pumping of a fluid.
    Type: Grant
    Filed: October 7, 2004
    Date of Patent: April 19, 2011
    Assignees: Pentagon Optimization Services Inc., Angel Energy Inc.
    Inventor: Daniel C. Simmons
  • Patent number: 7766079
    Abstract: A pumping installation for a gas producing well. A gas compressor is positioned on surface which receives gas. The compressor is powered by hydraulic fluid. An engine is positioned a sufficient distance from the gas producing well as not to pose a danger of gas explosion. A hydraulic reservoir is provided. Hydraulic fluid is circulated by the engine to supply hydraulic fluid from the hydraulic reservoir needed to power the compressor.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: August 3, 2010
    Assignee: Global Energy Services Ltd.
    Inventor: Clayton Hoffarth
  • Patent number: 7762321
    Abstract: A hydraulic oil well pumping arrangement employs a compensating type hydraulic pump, a directional valving arrangement and a proportioning valving arrangement. When the directional valve is energized, oil is directed to the rod end of the hydraulic cylinder. The rod or piston part of the hydraulic cylinder will then elevate until a first limit switch is actuated which then will de-energize the directional valve and send a current signal to the proportional valve. This current signal to the proportional valve forces it to open to a point at which the cylinder rod would extend at the desired velocity until it reaches a second limit switch. The second limit switch is near the bottom (for example, 1 foot, or 0.30 meters) of travel of the rod or piston. The current signal to the proportional valve is then decreased, creating a choking arrangement that forces the cylinder rod to decelerate. The cylinder rod then reaches another limit switch.
    Type: Grant
    Filed: February 1, 2007
    Date of Patent: July 27, 2010
    Assignee: Petro Hydraulic Lift System, L.L.C.
    Inventors: Michael A. Fesi, Willard J. Lapeyrouse, Kenneth H. Vincent
  • Patent number: 7744352
    Abstract: A jet pump assembly and method for removing fluid from a well bore extending into a formation is disclosed. The jet pump assembly includes a jet pump interposed between a tubing string and a packer. The jet pump includes a body having an outer surface, a lower tubular end, an upper tubular end connected to a lower end of the tubing string, and a central axial bore intersecting the upper tubular end at a discharge end and extending partially through the pump body toward the lower tubular end. The pump body further has a plurality of radial inlet ports intersecting the central axial bore and a plurality of production ports extending from the lower tubular end to the upper tubular end in a non-intersecting relation to the injection ports. The central axial bore is shaped to provide a non-restricted flow path from the point the injection ports intersect the central axial bore to the discharge end of the central axial bore.
    Type: Grant
    Filed: March 3, 2009
    Date of Patent: June 29, 2010
    Assignee: Latigo Pipe and Equipment, Inc.
    Inventor: Thomas Earl Parr
  • Patent number: 7546870
    Abstract: A method and system for the removal of produced liquid from a gas well extending from an earth surface through a subterranean gas-bearing formation using a thermodynamic cycle.
    Type: Grant
    Filed: May 8, 2008
    Date of Patent: June 16, 2009
    Assignee: BP Corporation North America Inc.
    Inventor: Bryan D. Dotson
  • Patent number: 7530799
    Abstract: Methods and apparatus for driving a positive displacement pump disposed within a wellbore are disclosed herein. Embodiments of the present invention provide a drive mechanism for driving the downhole positive displacement pump. In embodiments of the present invention, the positive displacement pump is hydraulically driven and mechanically counterbalanced. The drive mechanism may be mechanically or electrically controlled, or may be controlled by a combination of mechanical and electrical controls.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: May 12, 2009
    Inventor: Norris Edward Smith
  • Patent number: 7497667
    Abstract: A jet pump assembly for removing fluid from a well bore extending into a formation is disclosed. The jet pump assembly includes a jet pump interposed between a tubing string and a packer. The jet pump includes a body having an outer surface, a lower tubular end, an upper tubular end connected to a lower end of the tubing string, and a central axial bore intersecting the upper tubular end at a discharge end and extending partially through the pump body toward the lower tubular end. The pump body further has a plurality of radial inlet ports intersecting the central axial bore and a plurality of production ports extending from the lower tubular end to the upper tubular end in a non-intersecting relation to the injection ports. The central axial bore is shaped to provide a non-restricted flow path from the point the injection ports intersect the central axial bore to the discharge end of the central axial bore.
    Type: Grant
    Filed: August 23, 2005
    Date of Patent: March 3, 2009
    Assignee: Latigo Pipe and Equipment, Inc.
    Inventor: Thomas Earl Parr
  • Patent number: 7458786
    Abstract: An improved oil well pumping unit and method thereof configured for use on new or existing oil wells. The present invention is for mechanical operation of the subsurface pump and replaces existing mechanical pumping units. The present invention multiplies input purchased energy through mechanical links, pressurized fluid and/or gas, moving weights and counterweights and a control system in order to pump produced fluid through a new or existing conventional reciprocating oil well pump.
    Type: Grant
    Filed: March 4, 2005
    Date of Patent: December 2, 2008
    Inventor: Robert George Mac Donald
  • Patent number: 7380608
    Abstract: In a method for de-watering a gas well, the water is pumped by an inverted API pump acting as a reciprocating pump from a position in the well casing below the gas formation and the gas escapes through the well casing around the transport tubes. The reciprocating pump is driven by a downhole engine in the form of a cylinder and piston which is moved by a hydraulic pump at the surface acting to generate a flow in a hydraulic fluid to drive the piston from a start position to an end position and causing fluid to be transferred from the cylinder on the other side of the piston to a counterbalance chamber against a back pressure provided by a charge of nitrogen gas. At the end of a pumping stroke of the reciprocating pump, pressure in the hydraulic fluid from the hydraulic pump through is released to cause the back pressure of the counterbalance chamber to drive the piston back to the start position.
    Type: Grant
    Filed: December 12, 2005
    Date of Patent: June 3, 2008
    Inventor: Howard Geier
  • Patent number: 7314081
    Abstract: A method of pumping upper production fluid from an upper level of an underground pool of production fluid and pumping lower production fluid having a higher concentration of sand from a lower level during a single pump cycle comprises providing a dual action reciprocating piston pump comprising a pump barrel and a reciprocating piston dividing the pump barrel into a lower and upper chambers. On a downstroke upper production fluid is drawn from the upper level into the upper chamber through an upper intake, and lower production fluid present in the lower chamber is forced up a tube toward ground surface. On an upstroke lower production fluid is drawn from the lower level into the lower chamber through a lower intake, and upper production fluid in the upper chamber is forced up the tube toward ground surface.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: January 1, 2008
    Assignee: 1075878 Alberta Ltd.
    Inventor: Wade Tokarek
  • Patent number: 7044215
    Abstract: I disclose an apparatus for driving a submerged pump in a well, of the kind where the pump has a driving rod. A motor is connected to a double-reduction helical gear drive, and the gear drive has a threaded output shaft. The gear drive output shaft is removably connected to the pump driving rod. There is a back plate; the motor and gear drive are connected together to the back plate. The back plate has at least one slotted track for vertically adjusting the position of the motor and gear drive above the pump driving rod. The apparatus has a drive head housing attached to the well head. A pivot connects the drive head housing and the back plate, so that the motor and gear drive may be pivoted clear of the pump driving rod when the gear drive and pump rod are disconnected. A back plate rest connected to the drive head housing supports the back plate (and the motor and gear drive) when the motor and gear drive are pivoted clear of the pump driving rod.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: May 16, 2006
    Assignee: New Horizon Exploration, Inc.
    Inventor: Greg Boyles
  • Patent number: 6558128
    Abstract: A fluid pumping system includes a number of stages. Each stage has a fluid chamber having a top end with an air aperture and a bottom end with a fluid apertures. An air line is connected to the air aperture, and a fluid input conduit, with an input check valve, is connected to the fluid aperture. A float valve is disposed in the chamber directly between the fluid aperture and the air aperture. A fluid output conduit is connected to the fluid aperture above the input check valve. The float has a bottom end adapted to seal with the fluid aperture when the chamber is empty. A first set of pumping stages are supplied by a first compressed air line and a second set of pumping stages are supplied by a second compressed air line. Periodically, compressed air is supplied to a first set of pump stages to drive fluid from each of the first set of pump stages to a second set of stages, and vice versa.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: May 6, 2003
    Inventors: John E. Marvel, Michael A. Porch
  • Patent number: 6435838
    Abstract: A fluid pumping system includes a number of stages. Each stage has a fluid chamber having a top end with an air aperture and a bottom end with a fluid apertures. An air line is connected to the air aperture, and a fluid input conduit, with an input check valve) is connected to the fluid aperture. A float valve is disposed in the chamber directly between the fluid aperture and the air aperture. A fluid output conduit is connected to the fluid aperture above the input check valve. The float has a bottom end adapted to seal with the fluid aperture when the chamber is empty. A first set of pumping stages are supplied by a first compressed air line and a second set of pumping stages are supplied by a second compressed air line. Periodically, compressed air is supplied to a first set of pump stages to drive fluid from each of the first set of pump stages to a second set of stages, and vice versa.
    Type: Grant
    Filed: August 17, 2000
    Date of Patent: August 20, 2002
    Inventors: John E. Marvel, Michael A. Porch
  • Patent number: 6004114
    Abstract: A flow control assembly is provided for a submersible pump drive which has a hydraulic drive motor and a bearing pack for sealing a drive shaft which transfers drive from the drive motor to an oil well pump. The flow control assembly incorporates a production containment device for engaging said bearing pack The production containment device has a collar for supporting the bearing pack, drive shaft and hydraulic drive motor within the submersible pump drive, and a passageway through the collar for channeling fluid therethrough. The flow control assembly further includes a seal protection device for demountably engaging the bearing pack opposite the hydraulic drive motor. The seal protection device has a fluid deflecting cone shaped tip and a hollow cylindrical portion adjacent the tip for receiving a lubricant to impede any fluid entering the seal protection device from migrating through the bearing pack.
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: December 21, 1999
    Inventors: Edmund C. Cunningham, Gerald R. Leeb
  • Patent number: 5915475
    Abstract: A method and apparatus for pumping formation liquids provides a reciprocating down hole pump on the end of a coiled tubing string. In one embodiment, one fluid flow path is provided through the inside of the coiled tubing and another flow path is provided in an annulus between the coiled tubing and a, production string. In one embodiment, pressure delivered down the annulus to the pump moves a piston in a direction to move formation liquids upwardly to the surface. When pressure in the annulus is reduced, the hydrostatic weight of the pumped liquid moves the piston in a retracting direction to prepare for the next stroke. In other embodiments, the piston is moved downwardly, in retracting direction, by fluid pressure applied from the surface.
    Type: Grant
    Filed: July 22, 1997
    Date of Patent: June 29, 1999
    Inventors: Edward A. Wells, Paul S. Barter, Jr.
  • Patent number: 5827051
    Abstract: Regenerative hydraulic power transmission for subsurface pumps, including a power source, a variable flow rate hydraulic pump, means to reverse flow through the hydraulic pump responsive to change in direction of the subsurface pump stroke, and an inertial assist for the power source which gathers energy from the downstroke of the subsurface pump and utilizes the gathered energy to power the upstroke of the subsurface pump. The transmission can vary upstroke speed apart from downstroke speed, pump stroke length and dwell time of change in stroke direction.
    Type: Grant
    Filed: December 13, 1995
    Date of Patent: October 27, 1998
    Assignee: Air-Go Windmill, Inc.
    Inventor: Norris Edward Smith
  • Patent number: 5743716
    Abstract: A reversible flow variable rate hydraulic swashplate pump furnishes hydraulic fluid to stroke a piston supporting a subsurface pump. The controller determines reversal of pump flow and timing and speed of upstroke and downstroke of the subsurface pump. No valving restricts hydraulic fluid flow, and energy from the falling mass of the beam and sucker rods is accumulated during downstroke to be utilized during upstroke. The invention also includes the method steps of pumping hydraulic fluid to a cylinder containing a piston supporting the subsurface pump piston at a constant increasing rate until a maximum preset flow is reached, decreasing the flow to zero at a rate different than the increasing rate, reversing the hydraulic fluid flow to flow from the cylinder to the hydraulic pump at a constant increasing rate until maximum preset reverse flow is reached, and reducing reversed flow to zero at a rate different than the increasing flow rate.
    Type: Grant
    Filed: May 23, 1996
    Date of Patent: April 28, 1998
    Assignee: Air-Go Windmill, Inc.
    Inventor: Norris Edward Smith