Patent ID: 7380608
Filing Date: 2008-06-03
Classification: E21B,F04B,Y10S

Abstract:
1. A method of pumping liquid from a first location to a second location comprising: providing a hydraulic pump at the second location for generating a flow of hydraulic fluid under pressure; providing at the first location a cylinder having a piston therein; providing at the first location a hydraulic counterbalance chamber having back pressure therein; providing a first transport tube extending from the hydraulic pump at the second location to the cylinder at the first location on one side of the piston therein; providing at the first location a reciprocating pump for receiving and pumping the liquid; providing a second transport tube from the reciprocating pump at the first location to the second location; causing the hydraulic pump at the first location to generate a flow of a volume of the hydraulic fluid through the first transport tube to the cylinder at the second location on one side of the piston to drive the piston from a start position to an end position; causing fluid to be transferred from the cylinder on the other side of the piston by movement of the piston to the counterbalance chamber against the back pressure where the transferred fluid is stored under the back pressure; causing the movement of the piston to drive the reciprocating pump through a pumping stroke to pump the liquid into the second transport tube for transportation to the second location; and at the end of a pumping stroke of the reciprocating pump, releasing pressure in the hydraulic fluid from the hydraulic pump through the first transport tube to the cylinder so as to cause the back pressure of the counterbalance chamber to return the stored fluid under the back pressure back to the cylinder so that the back pressure acts to drive the piston back to the start position; and arranging the piston and the first transport tube such that the movement of the piston acts to force said volume of hydraulic fluid from the cylinder back through the first transport tube.