System for mooring a production vessel

Abstract

A system for mooring a floating production vessel comprising: two or more buoys anchored to the seafloor that are also connected directly to the floating production vessel; and one or more risers connected to at least one of the buoys that is also connected to one or more subsea wellheads or manifolds wherein the buoys are not connected to the floating vessel by a swivel and turret system.

1 . A system for mooring a floating production vessel comprising:
 a. two or more buoys anchored to the seafloor that are also connected directly to the floating production vessel; and   b. one or more risers connected to at least one of the buoys that is also connected to one or more subsea wellheads or manifolds   wherein the buoys are not connected to the floating vessel by a swivel and turret system.   
     
     
         2 . A system as claimed in  claim 1  wherein risers are connected to each of the two or more buoys. 
     
     
         3 . A system as claimed in  claim 1  wherein the buoys can be disconnected from the floating vessel by releasing the buoys to be submerged at a deeper depth than that when connected. 
     
     
         4 . A system as claimed in  claim 1  wherein each of the buoys is anchored to the seafloor by more than two mooring lines. 
     
     
         5 . A system as claimed in  claim 4  wherein the two or more buoys are anchored to the seafloor by a plurality of mooring lines positioned at an angle to the vertical. 
     
     
         6 . A system as claimed in  claim 1  wherein two or more buoys are connected to each other with one or more connection lines. 
     
     
         7 . A system as claimed in  claim 1  wherein the floating production vessel is a ship. 
     
     
         8 . A system as claimed in  claim 1  wherein the two or more buoys are not connected directly to each other. 
     
     
         9 . A method of mooring a floating production vessel comprising:
 a. providing two or more buoys that are anchored to the seafloor; and   b. connecting the two or more buoys to the floating vessel   wherein the buoys are not connected to the floating vessel by a swivel and turret system.   
     
     
         10 . A method as claimed in  claim 9  wherein the buoys are connected to each other with one or more connection lines. 
     
     
         11 . A method as claimed in  claim 9  wherein the two or more buoys are not connected directly to each other. 
     
     
         12 . A method of protecting production risers and the floating production vessel from the effects of a storm comprising:
 a. providing two or more buoys that are anchored to the seafloor and connected to a floating production vessel;   b. providing one or more production risers that are connected to a source of oil and gas production on the seafloor and to at least one of the buoys;   c. disconnecting all buoys that are connected to the one or more production risers from the floating production vessel; and   d. submerging all buoys to a depth of at least 10 meters below sea level.   
     
     
         13 . A method as claim in  claim 12  further comprising moving the floating production vessel away from the storm.