Lubrication system for subsea compressor

Abstract

A compression apparatus including a motor, a lubricant source, an umbilical, a compressor, a separation device, and a lubricant recycling assembly. The lubricant source provides a lubricant. The umbilical is fluidly connected to the lubricant source. The compressor is operatively connected to the motor, fluidly connected to the umbilical, and includes a compressor lubricant outlet and a compressor lubricant inlet that is fluidly connected to the umbilical. The separation device is fluidly connected to the compressor, and the lubricant source, and a well including a process fluid, wherein the separation device separates the process fluid into a liquid portion and a gaseous portion, and a portion of the lubricant mixes with the process fluid. The lubricant recycling assembly includes a dirty side fluidly connected to the compressor lubricant outlet, a clean side fluidly connected to the compressor lubricant inlet, a lubricant filter, and a lubricant pump.

1 . A compression system, comprising:
 a compressor;   a process fluid source containing a process fluid;   a lubricant source;   a process fluid pump;   a lubricant inlet line fluidly connecting the lubricant source to the compressor and the process fluid pump, wherein the lubricant inlet line provides a usable lubricant to the compressor and the process fluid pump from the lubricant source;   a separation device fluidly connected with the lubricant source, the process fluid source, the compressor, and the process fluid pump, wherein a portion of the usable lubricant mixes with the process fluid, and the process fluid is separated such that a gaseous portion of the process fluid is channeled to the compressor and a liquid portion of the process fluid is channeled to the process fluid pump;   a lubricant recycling line fluidly connected to the lubricant inlet line, the compressor, and the process fluid pump, wherein a used lubricant is discharged from the compressor and the process fluid pump into the lubricant recycling line, and the lubricant recycling line provides a recycled lubricant to the lubricant inlet line;   a lubricant filter fluidly connected to the lubricant recycling line, wherein the lubricant filter filters the used lubricant;   a lubricant pump fluidly connected to the lubricant recycling line, wherein the lubricant pump pumps the used lubricant through the lubricant recycling line; and   a lubricant cooler fluidly connected to the lubricant recycling line, wherein the lubricant cooler cools the used lubricant.   
     
     
         2 . The compression system of  claim 1 , further comprising a motor operatively connected to the compressor and fluidly connected to the lubricant recycling line and the separation device, wherein the used lubricant is also discharged from the motor into the lubricant recycling line, and the lubricant inlet line provides the usable lubricant to the motor. 
     
     
         3 . The compression system of  claim 2 , wherein the lubricant pump is integrated with the motor. 
     
     
         4 . The compression system of  claim 1 , wherein the lubricant pump is integrated with the process fluid pump. 
     
     
         5 . The compression system of  claim 1 , wherein the lubricant pump is integrated with the compressor. 
     
     
         6 . The compression system of  claim 1 , wherein the process fluid source is located beneath a surface of a body of water, and at least one of the compressor, process fluid pump, lubricant filter, lubricant pump, and lubricant cooler is located beneath the surface of the body of water, proximal the process fluid source. 
     
     
         7 . A compression apparatus, comprising:
 a motor;   a lubricant source providing a lubricant;   an umbilical fluidly connected to the lubricant source;   a compressor operatively connected to the motor, fluidly connected to the umbilical, and including a compressor lubricant outlet and a compressor lubricant inlet that is fluidly connected to the umbilical;   a separation device fluidly connected to the compressor, the lubricant source, and a well including a process fluid, wherein the separation device separates the process fluid into a liquid portion and a gaseous portion, and a portion of the lubricant mixes with the process fluid; and   a lubricant recycling assembly comprising:
 a dirty side fluidly connected to the compressor lubricant outlet; 
 a clean side fluidly connected to the compressor lubricant inlet; 
 a lubricant filter interposed between the clean side and the dirty side; and 
 a lubricant pump interposed between the clean side and the dirty side. 
   
     
     
         8 . The compression apparatus of  claim 7 , wherein the lubricant recycling assembly further comprises a lubricant cooler interposed between the clean side and the dirty side. 
     
     
         9 . The compression apparatus of  claim 8 , wherein the motor further comprises:
 a motor lubricant inlet fluidly connected to the umbilical; and   a motor lubricant outlet fluidly connected to the dirty side of the lubricant recycling assembly.   
     
     
         10 . The compression apparatus of  claim 9 , further comprising a process fluid pump fluidly connected to the separation device and comprising:
 a pump lubricant inlet fluidly connected to the umbilical; and   a pump lubricant outlet connected to the dirty side of the lubricant recycling assembly.   
     
     
         11 . The compression apparatus of  claim 10 , wherein the lubricant pump is integrated with the compressor, the process fluid pump, or the motor. 
     
     
         12 . The compression apparatus of  claim 10 , wherein the well is located beneath a surface of a body of water, and at least one of the motor, the compressor, process fluid pump, lubricant filter, lubricant pump, and lubricant cooler is located beneath the surface of the body of water, proximal the well. 
     
     
         13 . A method of lubricating a compression system, comprising:
 supplying a compressor with a usable lubricant from a remote source;   mixing at least a portion of the usable lubricant with a process fluid in a separation device to form a mixture;   separating the mixture into a gaseous portion and a liquid portion in the separation device;   channeling the gaseous portion to the compressor;   channeling the liquid portion to a process fluid pump;   discharging a used lubricant from the compressor and the process fluid pump;   recycling the used lubricant to form a recycled lubricant, wherein recycling the used lubricant comprises filtering the used lubricant; and   channeling the recycled lubricant to the compressor.   
     
     
         14 . The method of  claim 13 , wherein recycling the used lubricant further comprises:
 cooling the used lubricant with a lubricant cooler; and   pumping the used lubricant with a lubricant pump.   
     
     
         15 . The method of  claim 14 , further comprising integrating the lubricant pump with the compressor. 
     
     
         16 . The method of  claim 15 , further comprising mixing the recycled lubricant with the usable lubricant to form a mixed lubricant. 
     
     
         17 . The method of  claim 16 , further comprising:
 supplying the separation device with the mixed lubricant; and   mixing the mixed lubricant with the process fluid.   
     
     
         18 . The method of  claim 13 , wherein:
 the remote source is located on an oil platform on a body of water;   the compressor is located under a surface of the body of water; and   the usable lubricant is continuously supplied from the remote source through an umbilical to the compressor during operation of the compression system.