Method and system for pumping liquid from an offshore natural gas production well

Abstract

A pump assembly comprises a first piston near a lower end of a coiled water and/or other condensed liquid discharge conduit, which is actuated by second and third pistons that are arrange at the upper and lower ends of a hydraulic or pneumatic fluid conduit, wherein the third piston is connected to a floating body, which is oscillated by waves, such that a pair of one way check valves suck and push production water and other condensed liquids sequentially from a lower region of the well into a lower portion and subsequently into an upper portion of the coiled water and other condensed liquid outlet conduit.

1 . A method for pumping liquid from an offshore natural gas production well by means of a pump assembly that is actuated by wave energy derived from waves in a body of water surrounding an upper section of the well. 
     
     
         2 . The method of  claim 1 , wherein the pump assembly comprises a positive displacement pump, which is actuated to reciprocate in response to waves in the body of water, such as an ocean, sea, lake or river, surrounding an offshore gas production facility, such as a platform, to which the upper section of the well is connected. 
     
     
         3 . The method of  claim 2 , wherein the pump assembly comprises a positive displacement pump, which is arranged near a bottom of the well and is connected to a hydraulic or pneumatic power transfer conduit, which is connected to a positive displacement motor assembly that is arranged in the body of water. 
     
     
         4 . The method of  claim 3 , wherein the pump and motor assemblies each comprise piston and cylinder assemblies which are interconnected by the hydraulic or pneumatic power transfer conduit. 
     
     
         5 . The method of  claim 4 , wherein the piston of the piston and cylinder assembly of the motor assembly is arranged in a wave zone near the upper surface of the body of water, such that the piston is induced to oscillate in the cylinder in response to oscillating movement of the body of water at or near the upper surface thereof. 
     
     
         6 . The method of  claim 3 , wherein the pump assembly is connected to a first and second coiled tubing, which are suspended from a wellhead through the interior of a production tubing in the well, the first coiled tubing forms part of the hydraulic or pneumatic power transfer conduit between the positive displacement pump and motor assembly, and the second coiled tubing provides a production water and/or other liquid outlet conduit for discharging production water and/or other liquid from the bottom of the gas well to a production water and/or other liquid disposal facility. 
     
     
         7 . The method of  claim 6 , wherein a natural gas with a reduced production and/or other liquid content is produced through the production tubing surrounding the coiled tubings. 
     
     
         8 . The method of  claim 6 , wherein the coiled tubings are substantially coaxial relative to each other. 
     
     
         9 . The method of  claim 8 , wherein the second coiled tubing is arranged in the interior of the first coiled tubing. 
     
     
         10 . A system for inhibiting liquid loading in an offshore natural gas production well by pumping liquid from the well, the system comprising a pump assembly that is actuated by wave energy. 
     
     
         11 . The system of  claim 10 , wherein the pump assembly comprises a reciprocating pump, which is configured to reciprocate in response to waves in a body of water, such as an ocean, sea, lake or river, surrounding an offshore gas production facility, such as a platform, to which the well is connected. 
     
     
         12 . The system of  claim 11 , wherein the reciprocating pump comprises a positive displacement pump arranged near a bottom of the well and is connected to a hydraulic or pneumatic power transfer conduit, which is connected to a positive displacement motor that is arranged in the body of water. 
     
     
         13 . The system of  claim 12 , wherein the pump and motor assemblies each comprise piston and cylinder assemblies which are connected to each other by the hydraulic or pneumatic power transfer conduit. 
     
     
         14 . The system of  claim 13 , wherein the piston of the piston and cylinder assembly of the motor is connected to a floating body arranged in a wave zone near the upper surface of the body of water, such that the piston of the motor is induced to oscillate in the cylinder of the motor in response to waves at the upper surface of the body of water induced by wind, current and/or tides. 
     
     
         15 . The system of  claim 14 , wherein the pump comprises a first piston near a lower end of a coiled water and/or other condensed liquid discharge conduit, which is actuated by second and third pistons of the motor that are arrange at the upper and lower ends of a hydraulic or pneumatic power transfer conduit, wherein the third piston is connected to a floating body, which is oscillated by waves, such that a pair of one way check valves suck and push production water and other condensed liquids sequentially from a lower region of the well into a lower portion and subsequently into an upper portion of the coiled water and other condensed liquid outlet conduit.