Method and system for handling producing fluid

Abstract

Production fluid is received in a seabed facility ( 3 ) from a hydrocarbon reservoir and water is separated from the production fluid by a fluid separator vessel ( 15 ) in the seabed facility ( 3 ). The production fluid is then conveyed to a host facility ( 2 ) by a production fluid pipeline ( 4 ). The separated water enters a fluid clean-up unit ( 19 ) which removes hydrocarbons from the water, and the water is then passed through a photo-chromatic device ( 20 ) which measures the amount of oil in the water. Providing that the water is measured to contain not more than the predetermined threshold maximum limit of oil in water, it is disposed of into the sea surrounding the seabed facility ( 3 ).

1 . A method for handling production fluid, comprising the steps of: 
 receiving production fluid in an underwater facility ( 3 ) from a hydrocarbon reservoir;    separating water from the production fluid in the underwater facility ( 3 ); and    disposing of the water below the surface of the water in which the underwater facility ( 3 ) is located.    
   
   
       2 . A method as claimed in  claim 1 , including the step of purifying the water separated from the production fluid before the step of disposing of the water.  
   
   
       3 . A method as claimed in  claim 2 , including the step of measuring the purity of the water before the step of disposing of the water.  
   
   
       4 . A method as claimed in  claim 3 , including returning the purified water back for further purification when the result of measuring the water purity reveals that it has a purity level below a predetermined threshold level.  
   
   
       5 . A method as claimed in  claim 3 , wherein the measuring step comprises measuring the amount of oil in water.  
   
   
       6 . A method as claimed in  claim 1 , wherein the step of disposing of the water comprises disposing of the water into the water in which the underwater facility ( 3 ) is located.  
   
   
       7 . A method as claimed in  claim 1 , wherein the step of disposing of the water includes injecting the water into the hydrocarbon reservoir.  
   
   
       8 . A method as claimed in  claim 7 , including the additional step of combining the water with injection fluid from a host facility ( 2 ) before injection into the hydrocarbon reservoir.  
   
   
       9 . A method as claimed in  claim 1 , wherein the step of disposing of the water comprises injecting the water into a disposal well ( 26 ).  
   
   
       10 . A system ( 1 ) for handling production fluid, comprising an underwater facility ( 2 ) having production fluid separation means ( 15 ) for receiving production fluid from a hydrocarbon reservoir and separating water from the production fluid, and disposal means ( 18 , 24 ) for disposing of the water from the underwater facility to below the surface of the water in which the underwater facility is located.  
   
   
       11 . A system as claimed in  claim 10 , wherein the underwater facility ( 2 ) includes water purification means ( 19 ) for purifying water separated from the production fluid by the separation means ( 15 ) before the water is disposed of by the disposal means ( 18 , 24 ).  
   
   
       12 . A system as claimed in  claim 11 , including a measuring device ( 20 ) between the water purification means ( 19 ) and the disposal means ( 18 , 24 ) for measuring the purity of the purified water.  
   
   
       13 . A system as claimed in  claim 12 , wherein the underwater facility ( 2 ) has recirculation means ( 21 ) for delivering purified water back to the water purification means ( 19 ) when the result of measuring the water purity reveals that it has a purity level below a predetermined threshold level.  
   
   
       14 . A system as claimed in  claim 12 , wherein the measuring device ( 20 ) is arranged to measure the amount of oil in the water.  
   
   
       15 . A system as claimed in  claim 12 , wherein the measuring device ( 20 ) comprises a photochromatic device.  
   
   
       16 . A system as claimed in  claim 10 , wherein the disposal means ( 18 , 24 ) is arranged to dispose of the water into the water in which the underwater facility ( 3 ) is located.  
   
   
       17 . A system as claimed in  claim 10 , wherein the disposal means includes a connector ( 13 ) for enabling the disposal means ( 23 , 24 ) to be connected to a disposal well ( 26 ) or to the hydrocarbon reservoir.  
   
   
       18 . A retrievable module ( 12 ) for an underwater processing system, the module comprising the system as claimed in  claim 10.