Method and Apparatus for Thru-BOP Intervention Operations Using Riser System Components or Other Modular Components in a Structurally Sound Open-Water Intervention Configuration

Abstract

A well control assembly for use on subsea wells, especially during intervention or workover operations. The well control assembly is light weight, compact, and modular and, thus, can be deployed from much smaller vessels than conventional open water subsea equipment, while providing an internal diameter greater than or equal to the subsea trees upon which it would be deployed. Unlike conventional assemblies, tension and bending loads imparted by sea currents and/or a floating vessel can be resisted by the robust design of the well control assembly (and, in particular, load housing(s) thereof).

What is claimed: 
     
         1 . A well control apparatus for performing operations through a subsea tree having a central bore comprising:
 a) an emergency disconnect subassembly configured for attachment to the distal end of an open-water riser, wherein said emergency disconnect subassembly further comprises:
 i) a load housing defining an inner bore; 
 ii) a disconnect apparatus configured for selectively disconnecting said open-water riser from said well control apparatus; and 
   b) a well control subassembly configured for mounting to said subsea tree, wherein said well control subassembly further comprises a load housing defining an inner bore.   
     
     
         2 . The well control apparatus of  claim 1 , wherein said inner bores of said load housing of said emergency disconnect subassembly and said load housing of said well control subassembly are in linear alignment. 
     
     
         3 . The well control apparatus of  claim 2 , wherein said aligned inner bores of said load housings are greater than or equal to said central bore of said subsea tree. 
     
     
         4 . The well control apparatus of  claim 1 , further comprising a valve pack disposed within said inner bore of said load housing of said well control subassembly. 
     
     
         5 . The well control apparatus of  claim 4 , wherein said valve pack comprises a cutting device and at least one sealing valve. 
     
     
         6 . The well control assembly of  claim 5 , wherein said load housing of said well control assembly protects said valve pack from forces exerted by water current. 
     
     
         7 . The well control apparatus of  claim 1 , wherein said well control apparatus can be deployed from a multi-service vessel or boat having a moon pool. 
     
     
         8 . A well control apparatus for performing operations through a subsea tree having a central bore comprising:
 a) a modular emergency disconnect subassembly configured for attachment to the distal end of an open-water riser, wherein said modular emergency disconnect subassembly further comprises:
 i) a load housing defining an inner bore; 
 ii) a disconnect apparatus configured for selectively disconnecting said open-water riser from said well control apparatus; 
   b) a modular well control subassembly configured for mounting to said subsea tree, wherein said modular well control subassembly further comprises:
 i) a structure 
 iii) a load housing defining an inner bore disposed within said structure; and 
   c) a connector configured for operationally attaching said modular well control assembly to said subsea tree.   
     
     
         9 . The well control apparatus of  claim 8 , wherein said inner bores of said load housing of said modular emergency disconnect subassembly and said load housing of said modular well control subassembly are in linear alignment. 
     
     
         10 . The well control apparatus of  claim 9 , wherein said aligned inner bores of said load housings are greater than or equal to said central bore of said subsea tree. 
     
     
         11 . The well control apparatus of  claim 10 , further comprising a valve pack disposed within said inner bore of said load housing of said well control subassembly. 
     
     
         12 . The well control apparatus of  claim 11 , wherein said valve pack comprises a cutting device and at least one sealing valve. 
     
     
         13 . The well control assembly of  claim 12 , wherein said load housing of said modular well control subassembly protects said valve pack from forces exerted by water current. 
     
     
         14 . The well control apparatus of  claim 8 , wherein said well control apparatus can be deployed from a multi-service vessel or boat having a moon pool. 
     
     
         15 . A well control apparatus for performing operations through a subsea tree having a central bore comprising:
 a) an emergency disconnect subassembly configured for attachment to the distal end of an open-water riser, wherein said emergency disconnect subassembly further comprises:
 i) a load housing defining an inner bore; 
 ii) a disconnect apparatus configured for selectively disconnecting said open-water riser from said well control apparatus; 
   b) a well control subassembly configured for mounting to said subsea tree, wherein said well control subassembly further comprises a load housing defining an inner bore; and   c) a cutting device and at least one sealing valve disposed within said inner bore of said load housing of said well control subassembly, wherein said cutting device and at least one sealing valve are protected from water current forces by said load housing of said well control subassembly.