System for and method of restraining a subsurface exploration and production system

Abstract

A system for and method of limiting and controlling the unintended subsurface release of an exploration or production riser system is provided including one or more means for anchoring the riser or casing stack at one or more pre-determined points upon the length of the riser, and/or on the housing of an associated buoyancy chamber or the like, and/or on a particular portion of the riser as dictated by the operational environment, and/or on an anchor portion secured in the sea floor; and a network of restraining members disposed on the anchoring means. A lower anchoring portion includes one or more anchors disposed in communication with a wellhead, or with the sea floor or below the sea floor mud line, or with a well casing portion. A network of restraining members forms an essentially continuous connection from the buoyancy member portion to said bottom anchor portion. In a particular, though, non-limiting embodiment of the invention, a means for anchoring the system using pairs of anchors disposed at one or more predetermined points along the riser portion of the system is provided. Also disclosed is a variety of means and devices by which a surface vessel or a rig, etc., servicing a subsea well equipped with the present system may absorb or deflect impact forces originating from portions of the system that unexpectedly break free and rush upwards toward the surface vessel or rig.

1 . A method for restraining the release of a subsurface riser system, said method comprising the steps of:
 disposing one or more anchoring members at one or more predetermined points along a length of said riser system; and   disposing one or more restraining members in communication with said one or more anchoring members.   
   
   
       2 . The method of  claim 1 , wherein said step of disposing one or more anchoring members further comprises a step of disposing one or more anchoring members in communication with an associated buoyancy member. 
   
   
       3 . The method of  claim 2 , wherein said step of disposing one or more anchoring members further comprises a step of disposing one or more anchoring members on at least one surface of said buoyancy member. 
   
   
       4 . The method of  claim 2 , wherein said step of disposing one or more anchoring members further comprises a step of disposing one or more anchoring members on at least one longitudinal portion of an upper riser segment disposed above said buoyancy member. 
   
   
       5 . The method of  claim 2 , wherein said step of disposing one or more anchoring members further comprises a step of disposing one or more anchoring members on at least one longitudinal portion of a lower riser segment disposed beneath said buoyancy member. 
   
   
       6 . The method of  claim 1 , wherein said step of disposing one or more anchoring members further comprises a step of disposing one or more anchoring members on at least one portion of an associated well casing. 
   
   
       7 . The method of  claim 1 , wherein said step of disposing one or more anchoring members further comprises a step of disposing one or more anchoring members on at least one portion of an associated sea floor. 
   
   
       8 . The method of  claim 7 , wherein said step of disposing one or more anchoring members further comprises a step of disposing one or more anchoring members on at least one portion of the sea floor disposed beneath the mud line. 
   
   
       9 . The method of  claim 1 , wherein said step of disposing one or more restraining members further comprises a step of disposing a restraining member between a first predetermined point and a second predetermined point disposed along a length of the riser system. 
   
   
       10 . The method of  claim 1 , wherein said step of disposing a restraining member further comprises a step of disposing at least one restraining member between a buoyancy member and a predetermined point along a length of said system. 
   
   
       11 . The method of  claim 1 , wherein said step of disposing one or more restraining members further comprises a step of disposing at least one restraining member between a predetermined point along a length of said riser system and a wellhead disposed in communication with said system. 
   
   
       12 . The method of  claim 1 , wherein said step of disposing one or more restraining members further comprises a step of disposing at least one restraining member between a predetermined point along a length of said riser system and a predetermined point disposed beneath a wellhead associated with said system. 
   
   
       13 . The method of  claim 1 , wherein said step of disposing one or more restraining members further comprises a step of disposing at least one restraining member between a predetermined point along a length of said riser system and a predetermined point disposed beneath the sea floor mud line. 
   
   
       14 . The method of  claim 1 , wherein said step of disposing one or more anchoring members further comprises a step of disposing at least one anchoring member between a first predetermined point and a second predetermined point located along one or more lengths of said riser system, wherein said first predetermined point and said second predetermined point are disposed in functionally close proximity to one another, thereby constituting an effective anchoring pair. 
   
   
       15 . The method of  claim 14 , wherein said step of disposing one or more restraining members further comprises a step of disposing at least one additional restraining member between said first predetermined point and said second predetermined point of said anchoring pair. 
   
   
       16 . A system for restraining the release of a subsurface riser system, said system comprising:
 one or more anchoring members disposed at one or more predetermined points along a length of said riser system; and   one or more restraining members disposed in communication with said one or more anchoring members.   
   
   
       17 . The system of  claim 16 , wherein said system further comprises one or more anchoring members disposed in communication with an associated buoyancy member. 
   
   
       18 . The system of  claim 17 , wherein said system further comprises one or more anchoring members disposed on at least one surface of said buoyancy member. 
   
   
       19 . The system of  claim 17 , wherein said system further comprises one or more anchoring members disposed on at least one longitudinal portion of an upper riser segment disposed above said buoyancy member. 
   
   
       20 . The system of  claim 17 , wherein said system further comprises one or more anchoring members disposed on at least one longitudinal portion of a lower riser segment disposed beneath said buoyancy member. 
   
   
       21 . The system of  claim 16 , wherein said system further comprises one or more anchoring members disposed on at least one portion of an associated well casing. 
   
   
       22 . The system of  claim 16 , wherein said system further comprises one or more anchoring members disposed on at least one portion of an associated sea floor. 
   
   
       23 . The system of  claim 22 , wherein said system further comprises one or more anchoring members disposed on at least one portion of the sea floor disposed beneath the mud line. 
   
   
       24 . The system of  claim 16 , wherein said system further comprises at least one restraining member disposed between a first predetermined point and a second predetermined point disposed along a length of the riser system. 
   
   
       25 . The system of  claim 16 , wherein said system further comprises at least one restraining member disposed between a buoyancy member and a predetermined point along a length of said system. 
   
   
       26 . The system of  claim 16 , wherein said system further comprises at least one restraining member disposed between a predetermined point along a length of said riser system and a wellhead disposed in communication with said system. 
   
   
       27 . The system of  claim 16 , wherein said system comprises at least one restraining member disposed between a predetermined point along a length of said riser system and a predetermined point disposed beneath a wellhead associated with said system. 
   
   
       28 . The system of  claim 16 , wherein said system further comprises at least one restraining member disposed between a predetermined point along a length of said riser system and a predetermined point disposed beneath the sea floor mud line. 
   
   
       29 . The system of  claim 16 , wherein said system further comprises at least one anchoring member disposed between a first predetermined point and a second predetermined point located along one or more lengths of said riser system, wherein said first predetermined point and said second predetermined point are disposed in functional proximity to one another, thereby constituting an effective anchoring pair. 
   
   
       30 . The system of  claim 29 , wherein said system further comprises at least one additional restraining member disposed between said first predetermined point and said second predetermined point of said anchoring pair.