Hydraulically actuated double-acting positive displacement pump system for producing fluids from a wellbore

Abstract

A submersible downhole pumping system is provided. The pumping system is designed so that all fluid conduits and electrical signal conduits are internalized within a pumping assembly. This design provides a substantially constant and slim profile to the pumping assembly. The pumping assembly comprises a housing that houses a power assembly, a powered actuator assembly that is operatively linked to a production fluid assembly and a central bore that extends through the pumping assembly to provide fluid communication between the power assembly and a first end of the pumping assembly. The pumping system further includes a flow distributor/connector at the first end or pump head for providing fluids' communication between the pump head and a conducting system that extends from surface to the pumping system. The communication fluids include high pressure power hydraulic fluid, low pressure exhaust hydraulic fluid and pressurized produced wellbore fluid.

1 . A fluid conducting system for providing fluid communication between an above-ground system of equipment and a downhole pumping assembly, the fluid connecting system comprising:
 a first end and a second end defining an outer surface therebetween, the first end connectible to the above-ground system of equipment;   one or more internal fluid conduits for providing fluid communication between the first end and the second end; and   a connector connected to the second end for operatively coupling the one or more internal fluid conduits to the downhole pumping assembly, the connector comprising a central channel, a secondary channel and a production fluid channel.   
     
     
         2 . The fluid conducting system of  claim 1 , wherein a diameter of the connector is equal to or smaller than an outer diameter of the downhole pumping assembly. 
     
     
         3 . The fluid conducting system of  claim 1 , wherein the one or more internal fluid conduits comprise a first conduit for conducting a power fluid, the first conduit is fluidly connected to the central channel of the connector. 
     
     
         4 . The fluid conducting system of  claim 3 , wherein the one or more internal fluid conduits comprise a second conduit for conducting an exhaust fluid, the second fluid is fluidly connected to the internal channel. 
     
     
         5 . The fluid conducting system of  claim 4 , wherein the power fluid is of a higher pressure and lower temperature than the exhaust fluid. 
     
     
         6 . The fluid conducting system of  claim 4 or 5 , wherein the first conduit is positioned within the second conduit. 
     
     
         7 . The fluid conducting system of any one of  claim 3, 4, 5 or 6 , further comprising a third conduit for conducting a production fluid uphole from the downhole pumping assembly, the third conduit is fluidly connected to the production fluid channel. 
     
     
         8 . The fluid conducting system of  claim 7 , wherein the first conduit and the second conduit are positioned within the third conduit. 
     
     
         9 . The fluid conducting system of  claim 8 , wherein the third conduit is the wellbore. 
     
     
         10 . The fluid conducting system of  claim 9 , wherein the third conduit is positioned within the wellbore. 
     
     
         11 . The fluid conducting system of  claim 1 , wherein the one or more internal fluid conduits comprises a first set of nested fluid conduits and a second set of nested fluid conduits, wherein each set of nested fluid conduits comprises an inner conduit positioned within an outer conduit. 
     
     
         12 . The fluid conducting system of  claim 11 , wherein the outer conduit of each set of nested conduits is for conducting a production fluid uphole from the downhole pumping assembly. 
     
     
         13 . The fluid conducting system of  claim 11 or 12 , wherein the inner conduit of the first set of nested fluid conduits is for conducting a power fluid and the inner conduit of the second set of nested fluid conduits is for conducting an exhaust fluid, wherein the power fluid is of a higher pressure and lower temperature than the exhaust fluid. 
     
     
         14 . The fluid conducting system of any one of  claims 1-13 , wherein at least one of the one or more internal fluid conduits houses one or more electrical conductors that are extendible from the first end to the second end. 
     
     
         15 . The fluid conducting system of any one of  claim 1-14 , wherein the connector further comprises an internal channel for internalizing and guiding the one or more electrical conductors from the second end to operatively connect with the downhole pumping assembly. 
     
     
         16 . The fluid conducting system of  claim 14 , wherein the one or more conductors extend through the connector to operatively connect to the downhole pumping assembly. 
     
     
         17 . The fluid conducting system of any one of  claims 1 to 15 , further comprising one or more production string adapters for fluidly and sealingly and fluidly communicably connecting the one or more internal fluid conduits to the production channel. 
     
     
         18 . The fluid conducting system of  claim 4 , further comprising a cross-over valve operationally positionable between a first portion of the first conduit and a second portion of the first conduit and between a first portion of the second conduit and a second portion of the second conduit. 
     
     
         19 . The fluid conducting system of  claim 17 , wherein the cross-over valve is actuateable between a first position and second position, when in the first position the cross-over valve establishes fluid communication between the first and second portions of the first conduit and between the first and second portions of the second conduit. 
     
     
         20 . The fluid conducting system of  claim 18 , wherein when the cross-over valve is in the second position, the cross-over valve establishes fluid communication between the first portion of the first conduit and the second portion of the second conduit and between the first portion of the second conduit and the second portion of the first conduit. 
     
     
         21 . A downhole pumping assembly, the assembly comprising:
 a. a first end and a second end defining an outer surface therebetween, the outer surface having a substantially constant outer diameter;   b. a power assembly proximal the second end and configured to direct a power fluid;   c. a production fluid assembly proximal the first end and configured to receive wellbore fluids and comprising a production piston configured to direct the received wellbore fluids towards the first end;   d. a powered actuation assembly positioned adjacent the power assembly and in fluid communication therewith, the power actuation assembly is operatively coupled to the production fluid assembly, the powered actuation assembly configured to receive the power fluid and to move the production piston via the operative coupling for directing the received wellbore fluids towards the first end,
 wherein the power assembly comprises a switchable valve for directing the power fluid to a first face or a second face of a powered piston of the powered actuation assembly and comprising a check valve that is actuatable between a first position and a second position, when in the first position the checker valve is closed, when in the second position the checker valve may be opened by the power fluid for reversing a direction of power fluid flow through the power assembly. 
   
     
     
         22 . The downhole pumping assembly of  claim 21 , wherein the checker valve may be opened if the power assembly stops operations. 
     
     
         23 . The downhole pumping assembly of  claim 21 , further comprising a fluid conducting system for communicating the power fluid to the power assembly and for communicating an exhaust fluid from the power assembly. 
     
     
         24 . The downhole pumping assembly of  claim 21 , wherein the fluid conducting system comprises a first end and a second end defining an outer surface therebetween, the first end connectible to the above-ground system of equipment;
 one or more internal fluid conduits for providing fluid communication between the first end and the second end; and   a connector connected to the second end for operatively coupling the one or more internal fluid conduits to the downhole pumping assembly, the connector comprising a central channel, a secondary channel and a production fluid channel.   
     
     
         25 . The downhole system of  claim 22 , wherein the one or more internal fluid conduits comprises a power fluid conduit for communicating the power fluid to the power assembly and an exhaust fluid conduit for communicating the exhaust fluid from the power assembly. 
     
     
         26 . The downhole pumping system of  claim 23 , wherein the fluid conducting system further comprises a cross-over valve for establishing fluid communication between a first portion of the power fluid conduit and a second portion of an exhaust fluid conduit and for establishing fluid communication between a second portion of the power fluid conduit and a first portion of the exhaust fluid conduit. 
     
     
         27 . A method for reversing fluid flow within a system, the method comprising steps of:
 a. establishing flow of a first fluid in a first direction between a source of a first fluid to a power assembly, wherein the power assembly distributes the first fluid for operating a pumping system;   b. establishing flow of a second fluid in a second direction that is opposite to the first direction between the power assembly and the source of a second fluid, wherein the second fluid is a lower pressure than the first fluid;   c. reversing the flow of the first direction to the second direction.   
     
     
         28 . The method of  claim 25 , wherein the step of reversing comprises actuating a cross-over valve that is operatively coupled to a first conduit through which the first fluid flows and a second conduit through which the second fluid flows. 
     
     
         29 . The method of  claim 26 , wherein actuating the cross-over valve establishes flow of the first fluid through a first portion of the first conduit and a second portion of the second conduit. 
     
     
         30 . The method of  claims 26 and 27 , wherein actuating the cross-over valve establishes flow of the second fluid through a second portion of the first conduit and a first portion of the first conduit. 
     
     
         31 . The method of claim of any one of  claims 25-28 , wherein the step of reversing further comprises a step of opening a checker valve in the power assembly for establishing the flow of the first fluid in the second direction. 
     
     
         32 . The method of any one of  claims 25-28 , wherein the first fluid is a power hydraulic fluid. 
     
     
         33 . The method of any one of  claims 25-27 , wherein the second fluid is an exhaust hydraulic fluid.