System and method of installing and maintaining an offshore exploration and production system having an adjustable buoyancy chamber

Abstract

A system and method of establishing an offshore exploration and production system is disclosed, in which a well casing is disposed in communication with an adjustable buoyancy chamber and a well hole bored into the floor of a body of water. A lower connecting member joins the well casing and the chamber, and an upper connecting member joins the adjustable buoyancy chamber and a well terminal member. The chamber's adjustable buoyancy enables an operator to vary the height or depth of the well terminal member, and to vary the vertical tension imparted to drilling and production strings throughout exploration and production operations. Also disclosed is a system and method of adjusting the height or depth of a wellhead while associated vertical and lateral forces remain approximately constant. A variety of well isolation members, lateral stabilizers and anchoring means, as well as several methods of practicing the invention, are also disclosed.

1 . A method of transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water to a fluid retention vessel disposed nearer the surface of said body of water, said method comprising: 
 buoyantly supporting a well control system within said body of water;    positioning said well control system through said subsurface wellhead;    initiating a fluid flow from said subsurface wellhead;    receiving said fluid flow from said subsurface wellhead using a fluid flow receiving means;    transferring said fluid flow from said fluid flow receiving means to said well control system; and    transferring said fluid flow from said well control system to said fluid retention vessel.    
   
   
       2 . The method of transferring fluid flow initiated from a subsurface wellhead of  claim 1 , wherein said method further comprises: 
 buoyantly supporting said well control system within said body of water using a buoyancy chamber.    
   
   
       3 . The method of transferring fluid flow initiated from a subsurface wellhead of  claim 1 , wherein said method further comprises: 
 positioning said well control system through said subsurface wellhead using a stress joint.    
   
   
       4 . The method of transferring fluid flow initiated from a subsurface wellhead of  claim 3 , wherein said method further comprises: 
 receiving said fluid flow from said subsurface wellhead using said stress joint.    
   
   
       5 . The method of transferring fluid flow initiated from a subsurface wellhead of  claim 1 , wherein said method further comprises: 
 transferring said fluid flow from said fluid flow receiving means to said well control system using production casing.    
   
   
       6 . The method of transferring fluid flow initiated from a subsurface wellhead of  claim 1 , wherein said method further comprises: 
 transferring said fluid flow from said well control system to said fluid retention vessel using at least one of a production tree, a blowout preventer, and a wellhead disposed nearer the surface of said body of water than said subsurface wellhead.    
   
   
       7 . A means for transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water to a fluid retention vessel disposed nearer the surface of said body of water, said means comprising: 
 means for buoyantly supporting a well control system within said body of water; means for positioning said well control system through said subsurface wellhead;    means for initiating a fluid flow from said subsurface wellhead;    means for receiving said fluid flow from said subsurface wellhead;    means for transferring said fluid flow from said subsurface wellhead to said well control system; and    means for transferring said fluid flow from said well control system to said fluid retention vessel.    
   
   
       8 . The means for transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water of  claim 7 , wherein said means further comprises: 
 a buoyancy chamber for supporting said well control system within said body of water.    
   
   
       9 . The means for transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water of  claim 7 , wherein said means further comprises: 
 a stress joint for positioning said well control system through said subsurface wellhead.    
   
   
       10 . The means for transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water of  claim 9 , wherein said stress joint is also used for receiving said fluid flow from said subsurface wellhead.  
   
   
       11 . The means for transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water of  claim 7 , wherein said means further comprises: 
 a length of production casing for transferring said fluid flow from said subsurface wellhead to said well control system.    
   
   
       12 . The means for transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water of  claim 7 , wherein said means further comprises: 
 at least one of a production tree, a blowout preventer, and a wellhead disposed nearer the surface than said subsurface wellhead used for transferring said fluid flow from said well control system to said fluid retention vessel.    
   
   
       13 . A system for transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water to a fluid retention vessel disposed nearer the surface of said body of water, said system comprising: 
 a buoyancy chamber for buoyantly supporting a well control system within said body of water;    a means for positioning said well control system through said subsurface wellhead;    a means for initiating a fluid flow from said subsurface wellhead;    a fluid flow receiving means for receiving said fluid flow from said subsurface wellhead;    a length of production casing for transferring said fluid flow from said fluid flow receiving means to said well control system; and    at least one of a production tree, a blowout preventer and a wellhead disposed nearer the surface of said body of water used for transferring said fluid flow from said well control system to said fluid retention vessel.    
   
   
       14 . The system for transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water of  claim 13 , wherein said means for positioning said well control system through said subsurface wellhead further comprises a stress joint.  
   
   
       15 . The system for transferring fluid flow initiated from a subsurface wellhead disposed beneath the surface of a body of water of  claim 14 , wherein said stress joint is also used to receive said fluid flow from said subsurface wellhead.