Subsea pumping system

Abstract

The invention concerns a subsea pumping system that comprises an reciprocating pump such as a membrane pump or a hose pump. The motive fluid for the pump is obtained from one of the well fluids which is pressurized in a separate stage.

1 . A subsea pumping system for use in a remote location such as a subsea hydrocarbon production facility, the subsea pumping system comprising:
 a source of high pressure fluid; and   a fluid driven reciprocating pump;   wherein the high pressure fluid is used as a motive fluid for the pump; and   means for creating pressure pulses in the motive fluid.   
     
     
         2 . The subsea pumping system according to  claim 1 , wherein the source of high pressure fluid is produced gas pressurized by a compressor. 
     
     
         3 . The subsea pumping system according to  claim 1 , wherein the source of high pressure fluid is produced liquids pressurized by a liquid pump. 
     
     
         4 . The subsea pumping system according to  claim 1 , wherein the source of high pressure fluid is an injection fluid provided by a pump located at a topside facility. 
     
     
         5 . The subsea pumping system according to  claim 1 , wherein the reciprocating pump is a diaphragm pump. 
     
     
         6 . The subsea pumping system according to  claim 1 , wherein the reciprocating pump is a hose diaphragm pump. 
     
     
         7 . The subsea pumping system according to  claim 1 , wherein the reciprocating pump is a piston pump. 
     
     
         8 . The subsea pumping system according to  claim 1 , wherein the means for creating pressure pulses comprises at least one valve arranged between the source of high pressure fluid and the pump. 
     
     
         9 . The subsea pumping system according to  claim 8 , the means for creating pressure pulses comprises an inlet valve and an outlet valve which are synchronized to provide the pulses. 
     
     
         10 . The subsea pumping system according to  claim 8 , wherein the means for creating pressure pulses comprises a rotating sequencing valve. 
     
     
         11 . The subsea pumping system according to  claim 10 , wherein the rotating sequencing valve has a rotational axis which is parallel to a pipeline axis for a pipeline in which the valve is arranged. 
     
     
         12 . The subsea pumping system according to  claim 1 , further comprising at least one separator. 
     
     
         13 . A method for operating a subsea reciprocating pump, the method comprising the steps of:
 separating out a first fluid phase from a well stream comprising a plurality of phases;   increasing the pressure of said first fluid phase; and   using a portion of the pressurized first fluid phase as a motive fluid for the reciprocating pump.   
     
     
         14 . The method according to  claim 13  wherein the pressurized first fluid phase is fed to the reciprocating pump through a sequential valve. 
     
     
         15 . The method according to  claim 13 , further comprising the step of the regulating a pressure differential in the first fluid phase. 
     
     
         16 . The subsea pumping system according to  claim 10 , wherein the rotating sequencing valve has a rotational axis which is transverse to a pipeline axis for a pipeline in which the valve is arranged.