Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps

Abstract

The present invention relates to the use of water-based control fluid in subsea systems as barrier fluid for electric motors ( 2 ) coupled to subsea pumps ( 1 ). For that purpose, a hose (HFL) ( 12 ) is arranged between an umbilical termination unit ( 9 ) and the electric motor ( 2 ) of the submersible pump ( 1 ), by means of a connection plate (MQC) ( 7 ). This installation makes more rational use of the space on the floating production unit by reducing the number of devices required for the implementation thereof, and by facilitating logistics regarding these products and devices.

1 . Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps, comprising a platform ( 10 ) in which is installed a single hydraulic power unit (HPU) ( 5 ), provided with hydraulic control fluid and connected by an umbilical ( 6 ) to the umbilical termination unit ( 9 ), where a control module ( 8 ) and valves and “chokes” ( 11 ) are interconnected through hydraulic coupling plates (MQC) ( 7 ), wherein the said umbilical termination unit ( 9 ) is provided with a hose (HFL) ( 12 ) interconnecting it with the electric motor ( 2 ) of the pump ( 1 ) via one of the hydraulic coupling plates (MQC) ( 7 ), in such way that the hydraulic control fluid is also used as barrier fluid in the said motor ( 2 ) and centrifugal pump ( 1 ) assembly. 
     
     
         2 . Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps, according to  claim 1 , wherein the said installation provides the achievement of an overpressure of the barrier fluid relative to the inlet ( 3 ) of the process fluid. 
     
     
         3 . Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps, according to  claim 1 , wherein the hydraulic circuit originating from the hydraulic power unit ( 5 ) is enough to perform simultaneously the hydraulic control of the subsea system ( 8 ,  11 ) and supply of the barrier fluid for electric motor ( 2 ) of the subsea pump ( 1 ). 
     
     
         4 . Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps, according to  claim 1 , wherein the fluid used for control and for barrier fluid is a water based-fluid. 
     
     
         5 . Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps, according to  claim 1 , wherein the utilization of infrastructure generally existent on the platform is allowed. 
     
     
         6 . Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps, according to  claim 1 , wherein utilization of the control umbilical is allowed, with the fluid redistribution totally performed in the subsea environment. 
     
     
         7 . Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps, according to  claim 1 , wherein in the case of platforms with “turret”, the hydraulic paths in the “swivel” are used for distributing fluid. 
     
     
         8 . Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps, according to  claim 1 , wherein the logistics of fluids and offshore supplies already existing on the platform are used. 
     
     
         9 . Installation for using control fluid as barrier fluid for electric motors coupled to subsea pumps, according to  claim 1 , wherein there is no need to change quality requirements of the control fluid for use as barrier fluid.