Vessel-based water injection systems

Abstract

A marine vessel may be configured with a water pump and seawater treatment equipment for use in providing a marine vessel water pumping platform for pumping water into a subsea reservoir to help maintain or increase pressure to assist with producing oil and/or natural gas. The marine vessel water pumping platform allows for the pump and seawater treatment equipment to be continuously used for pumping operations as the marine vessel may be moved between subsea reservoir sites, which helps reduce maintenance costs. The water pump may be lower in minimal flow capacity than water pumps on platforms, thereby allowing for more diversity in supporting different oil and/or gas pumping in offshore drilling operations.

What is claimed is: 
     
         1 . A method for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas, said method comprising:
 positioning a marine vessel including a pump configured to pump water to a subsea manifold in fluid communication with the subsea reservoir at the subsea manifold;   treating seawater by seawater treatment equipment to produce treated seawater in preparation for pumping the treated seawater into the subsea reservoir; and   pumping, by the pump, the treated seawater through one or more conduits in fluid communication with the subsea manifold to cause fluid pressure in the subsea reservoir to be maintained or increased.   
     
     
         2 . The method according to  claim 1 , wherein positioning the marine vessel includes dynamically positioning the marine vessel in a substantially fixed location. 
     
     
         3 . The method according to  claim 1 , further comprising:
 fluidly connecting a water conduit injection tree to the subsea manifold in fluid connection with the subsea reservoir; and   fluidly connecting a conduit between the water injection pump and the water conduit injection tree.   
     
     
         4 . The method according to  claim 3 , further comprising:
 disconnecting the water conduit injection tree from the subsea manifold; and   fluidly connecting the conduit between the pump and a second subsea manifold in fluid connection with a second subsea reservoir.   
     
     
         5 . The method according to  claim 1 , wherein fluidly connecting a conduit includes fluidly connecting a drill pipe riser and flexible jumper. 
     
     
         6 . The method according to  claim 1 , wherein fluidly connecting a conduit includes fluidly connecting at least one pair of a coiled tubing riser and flexible jumper. 
     
     
         7 . The method according to  claim 1 , wherein fluidly connecting a conduit includes fluidly connecting a flexible pipe riser. 
     
     
         8 . A system for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas, said system comprising:
 a marine vessel;   a pump disposed on the marine vessel and configured to pump water to a subsea manifold in fluid communication with the subsea reservoir;   seawater treatment equipment configured to produce treated seawater in preparation for pumping the treated seawater into the subsea reservoir; and   one or more conduits in fluid communication with the pump and subsea manifold to enable the treated seawater to be pumped therethrough by the pump to cause fluid pressure in the subsea reservoir to be maintained or increased.   
     
     
         9 . The system according to  claim 8 , wherein positioning the marine vessel includes a propulsion control system configured to dynamically position the marine vessel in a substantially fixed location when the pump is pumping the treated seawater. 
     
     
         10 . The system according to  claim 8 , further comprising:
 a water conduit injection tree configured to the subsea manifold in fluid connection with the subsea reservoir; and   a conduit fluidly connected between the water injection pump and the water conduit injection tree.   
     
     
         11 . The system according to  claim 10 , wherein:
 the conduit is fluidly disconnected from the pump and the water conduit injection tree from the subsea manifold; and   the conduit being fluidly connected between the pump and a second subsea manifold in fluid connection with a second subsea reservoir.   
     
     
         12 . The system according to  claim 8 , wherein the conduit includes a drill pipe riser and flexible jumper. 
     
     
         13 . The system according to  claim 8 , wherein the conduit includes a drill pipe riser and flexible jumper. 
     
     
         14 . The system according to  claim 8 , wherein the conduit includes at least one pair of a coiled tubing riser and flexible jumper. 
     
     
         15 . The system according to  claim 8 , wherein the conduit includes a flexible pipe riser. 
     
     
         16 . A method for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas, said method comprising:
 positioning a pump on a seabed, the pump configured to pump water to a subsea manifold in fluid communication with the subsea reservoir;   positioning seawater treatment equipment on the seabed, the seawater treatment equipment configured to produce treated seawater in preparation for the pump to pump the treated seawater into the subsea manifold to the subsea reservoir;   fluidly connecting the pump and seawater treatment equipment together;   fluidly connecting the pump to the subsea manifold through one or more conduits;   positioning a marine vessel including an electric power generator at the pump and seawater treatment equipment;   electrically connecting the electric power generator to the pump;   treating seawater by the seawater treatment equipment to produce treated seawater in preparation for the pump to pump the treated seawater into the subsea reservoir; and   pumping, by the pump, the treated seawater through the one or more conduits in fluid communication with the subsea manifold to cause fluid pressure in the subsea reservoir to be maintained or increased.   
     
     
         17 . The method according to  claim 16 , wherein positioning the marine vessel includes dynamically positioning the marine vessel in a substantially fixed location. 
     
     
         18 . The method according to  claim 16 , further comprising:
 fluidly connecting a water injection tree to the subsea manifold in fluid connection with the subsea reservoir; and   fluidly connecting a conduit between the water injection pump and the water injection tree.   
     
     
         19 . The method according to  claim 18 , further comprising:
 disconnecting the water conduit injection tree from the subsea manifold; and   fluidly connecting the conduit between the pump and a second subsea manifold in fluid connection with a second subsea reservoir.   
     
     
         20 . The method according to  claim 16 , further comprising mounting the pump onto a skid for deployment to the seabed.