Double hydraulic activated receptacle pump

Abstract

A downhole well pump has a housing with a housing bore having an upper section, a lower section and an intermediate section with a larger inner diameter than inner diameters of the upper and lower sections. A plunger has an upper plunger portion in the upper section of the housing bore, a piston in the intermediate section of the housing bore, and a lower plunger portion in the lower section of the housing bore. A hydraulic pump at the surface alternately supplies hydraulic fluid pressure to the upper and lower sides of the piston to cause the plunger to move upward and downward. A standing valve in the housing admits well fluid into the housing during the lifting stroke. A travelling valve moves in unison with the plunger for discharging well fluid from the housing during the lifting stroke.

1 . An apparatus for pumping well fluid from a well, comprising:
 a housing for securing to a string of tubing, the housing having a housing bore with an upper section, a lower section and an intermediate section between the upper and lower sections, the intermediate section having a larger inner diameter than inner diameters of the upper and lower sections;   a plunger carried reciprocally in the housing between a lifting stroke and a retracting stroke, the plunger having an upper plunger portion in sliding, sealing engagement with the upper section of the housing bore, the plunger having a lower plunger portion in sliding, sealing engagement with the lower section of the housing bore;   a piston on the plunger that moves in unison with the plunger and is in sliding, sealing engagement with the intermediate section of the housing bore;   a lifting stroke port in the housing leading to the intermediate section of the housing bore below the piston;   a retracting stroke port in the housing leading to the intermediate section of the housing above the piston;   a hydraulic pump assembly for placement adjacent a wellhead of the well and in fluid communication with the lifting stroke port and the retracting stroke port, the hydraulic pump assembly having means for alternately supplying hydraulic fluid pressure to the lifting fluid port to cause the plunger to move upward, and for supplying hydraulic fluid pressure to the retracting fluid port to push the plunger downward;   a well fluid intake in the housing;   a standing valve in the housing for admitting well fluid from the well through the well fluid intake into the housing during the lifting stroke of the plunger;   a well fluid discharge in the housing; and   a travelling valve that moves in unison with the plunger for discharging well fluid from the housing out the well fluid discharge into the string of tubing during the lifting stroke of the plunger.   
     
     
         2 . The apparatus according to  claim 1 , further comprising:
 a retracting stroke fluid line leading from the retracting stroke port to the hydraulic pump assembly.   
     
     
         3 . The apparatus according to  claim 1 , further comprising:
 a lifting stroke fluid line leading from the lifting stroke port to the hydraulic pump assembly.   
     
     
         4 . The apparatus according to  claim 1 , further comprising:
 a retracting stroke fluid line leading from the retracting stroke port to the hydraulic pump assembly;   a lifting stroke fluid line leading from the lifting stroke port to the hydraulic pump assembly; and wherein the means for alternately supplying hydraulic fluid pressure comprises:   a directional control valve connected between the retracting stroke fluid line and the lifting stroke fluid line that alternately shifts hydraulic fluid pressure between the lifting stroke fluid line and the retracting stroke fluid line.   
     
     
         5 . The apparatus according to  claim 1 , wherein the means for alternately supplying hydraulic fluid comprises:
 a directional control valve that alternately shifts hydraulic fluid pressure between the lifting stroke port and the retracting stroke port.   
     
     
         6 . The apparatus according to  claim 1 , further comprising:
 a lower adapter secured to and forming a part of the housing, the lower adapter having an upward facing shoulder extending outward from an exterior of the housing;   the lifting stroke port having an outer portion extending downward from the upward facing shoulder into the lower adapter; and   a lifting stroke line in fluid communication with the hydraulic pump assembly and extending alongside the housing into the lifting stroke port, the lifting stroke line being parallel to an axis of the housing.   
     
     
         7 . The apparatus according to  claim 6 , further comprising:
 an upper adapter secured to and forming a part of the housing, the upper adapter being above the lower adapter and having an upward facing shoulder extending outward from the exterior of the housing;   the retracting stroke port having an outer portion extending downward from the upward facing shoulder of the upper adapter into the upper adapter;   a retracting stroke line in fluid communication with the hydraulic pump assembly and extending alongside the housing into the retracting stroke port, the retracting stroke line being parallel to the axis of the housing.   
     
     
         8 . The apparatus according to  claim 6 , wherein:
 the lower adapter has a bore that is coaxial with the axis of the housing; and   the lower adapter has an outer diameter that is eccentric relative to the axis of the housing.   
     
     
         9 . The apparatus according to  claim 1 , further comprising:
 a plunger bore extending through the plunger;   wherein the travelling valve is mounted in the plunger bore; and   the plunger bore is in fluid communication with the standing valve for receiving well fluid from the well fluid intake.   
     
     
         10 . An apparatus for pumping well fluid from a well, comprising:
 a housing for securing to a string of tubing, the housing having a housing bore with an upper section, a lower section and an intermediate section between the upper and lower sections, the intermediate section having a larger inner diameter than inner diameters of the upper and lower sections;   a plunger carried reciprocally in the housing between a lifting stroke and a retracting stroke, the plunger having an upper plunger portion in sliding, sealing engagement with the upper section of the housing bore, the plunger having a lower plunger portion in sliding, sealing engagement with the lower section of the housing bore, the plunger having a bore extending therethrough;   a piston on the plunger that moves in unison with the plunger and is in sliding, sealing engagement with the intermediate section of the housing bore;   a lifting stroke port in the housing leading to the intermediate section of the housing bore below the piston;   a retracting stroke port in the housing leading to the intermediate section of the housing bore above the piston;   a hydraulic pump adapted to be placed adjacent a wellhead of the well;   a lifting stroke fluid line extending from the hydraulic pump to the lifting stroke port for supplying hydraulic fluid pressure from the hydraulic pump to the lifting stroke port to cause the plunger to move upward in the lifting stroke;   a retracting stroke fluid line extending from the hydraulic pump to the retracting stroke port for supplying hydraulic fluid pressure from the hydraulic pump to the retracting stroke port to cause the plunger to move downward in the retracting stroke;   a well fluid intake in the housing;   a standing valve in the housing below the plunger that opens a path from the well fluid intake to the plunger bore during the lifting stroke, and closes the path from the plunger bore to the well fluid intake during the retracting stroke of the plunger; and   a travelling valve in the plunger bore that closes the plunger bore during the lifting stroke and opens the plunger bore during the retracting stroke.   
     
     
         11 . The apparatus according to  claim 10 , wherein:
 the hydraulic pump assembly includes a directional control valve that alternately supplies hydraulic fluid pressure to the lifting stroke fluid line and to the retracting stroke fluid line.   
     
     
         12 . The apparatus according to  claim 10 , wherein the inner diameter of the lower section of the housing bore is at least equal to the inner diameter of the upper section of the housing bore. 
     
     
         13 . The apparatus according to  claim 10 , wherein the standing valve is mounted in the lower section of the housing bore. 
     
     
         14 . The apparatus according to  claim 10 , wherein:
 the housing has a lower portion containing the lower section of the housing bore, an upper portion containing the upper section of the housing bore, and an intermediate portion containing the intermediate section of the housing bore; wherein the apparatus further comprises:   a lower adapter connected between the lower portion and the intermediate portion of the housing, the lower adapter having an adapter bore through which the lower portion of the plunger passes;   an outer portion of the lower adapter extending laterally outward from the lower portion of the housing relative to a longitudinal axis of the housing; and   wherein the lifting stroke port extends through the outer portion of the lower adapter to the lower section of the housing bore.   
     
     
         15 . The apparatus according to  claim 14 , wherein:
 the outer portion of the lower adapter has an upward facing shoulder;   the lifting stroke port has an outer portion extending downward from the shoulder into the lower adapter;   the lifting stroke fluid line has a lower end extending into the outer portion of the lifting stroke port; and   the lifting stroke fluid line extends alongside the intermediate and upper portions of the housing parallel to the axis.   
     
     
         16 . The apparatus according to  claim 14 , wherein:
 the lifting stroke port has a lateral portion extending inward from the outer portion of the lifting stroke port and an inner portion extending upward from the lateral portion to an upper end of the lower adapter.   
     
     
         17 . A method of pumping well fluid from a well with a downhole hydraulic drive comprising:
 a housing suspended on production tubing in the well, the housing having a housing bore with an upper section, a lower section and an intermediate section between the upper and lower sections, the intermediate section having a larger inner diameter than inner diameters of the upper and lower sections;   a plunger carried reciprocally in the housing between a lifting stroke and a retracting stroke, the plunger having an upper plunger portion in sliding, sealing engagement with the upper section of the housing bore, the plunger having a lower plunger portion in sliding, sealing engagement with the lower section of the housing bore;   a piston on the plunger that moves in unison with the plunger and is in sliding, sealing engagement with the intermediate section of the housing bore;   a standing valve in the housing in fluid communication with well fluid in the well; and   a travelling valve that moves in unison with the plunger and is in fluid communication with the production tubing; the method comprising:   supplying hydraulic fluid pressure to the intermediate section of the housing bore below the piston to cause the plunger to move upward in the lifting stroke;   opening the standing valve and closing the travelling valve to lift a column of fluid in the production tubing during the lifting stroke; then   supplying hydraulic fluid pressure to the intermediate section of the housing bore above the piston to push the plunger downward in the retracting stroke; and   closing the standing valve and opening the travelling valve during the retracting stroke.   
     
     
         18 . The method according to  claim 17 , wherein:
 the plunger has a plunger bore extending therethrough;   the travelling valve is mounted in the plunger bore; and   the standing valve is located below the lower plunger portion; and the method further comprises:   flowing well fluid through the standing valve into the plunger bore during the lifting stroke; and   blocking well fluid from flowing downward out of the plunger bore and through the standing valve during the retracting stroke.   
     
     
         19 . The method according to  claim 17 , wherein supplying hydraulic fluid pressure to the intermediate section of the housing bore comprises:
 operating a hydraulic pump adjacent a wellhead of the well; and   alternately supplying hydraulic fluid pressure from the hydraulic pump to the intermediate section of the housing bore below and above the piston.   
     
     
         20 . The method according to  claim 19 , wherein alternately supplying hydraulic fluid pressure from the hydraulic pump comprises:
 flowing an output from the hydraulic pump through a directional control valve; and   alternately shifting the directional control valve.