Apparatus and method for subsea equipment removal and installation

Abstract

Provided is a subsea tool for engaging and/or disengaging a first member that is configured to be in contact with a second member. The tool may include a frame configured for fitting around or on top of a peripheral surface of the first member, the frame having mounted thereon one or more first engagement mechanisms having one or more first engagement members configured for moving into and out of engagement with the peripheral surface of the first member, and one or more second engagement mechanisms having one or more second engagement members for engaging the second member. The second engagement members may extend and retract relative to the frame and may be hydraulically driven. Provided also is a method of disengaging the first subsea member that is in contact with the subsea second member, and a method of engaging the first member into contact with the subsea second member.

1 . A subsea tool for engaging and/or disengaging a first member that is configured to be in contact with a second member, the tool comprising:
 a frame configured for fitting around or on top of a peripheral surface of the first member, the frame having mounted thereon;   one or more first engagement mechanisms having one or more first engagement members configured for moving into and out of engagement with the peripheral surface of the first member; and   one or more second engagement mechanisms having one or more second engagement members for engaging the second member, the second engagement members being configured for extending and retracting relative to the frame;   wherein the one or more second engagement members are hydraulically driven.   
     
     
         2 . A subsea tool as claimed in  claim 1 , wherein the first member is a gasket and the second member is a subsea wellhead or subsea equipment. 
     
     
         3 . A subsea tool as claimed in  claim 1 , wherein a plurality of first engagement mechanisms and a plurality of second engagement mechanisms are provided on the frame. 
     
     
         4 . A subsea tool as claimed in  claim 3 , wherein the frame comprises an annular body member having an inwardly facing surface profiled to be substantially congruent with an outer profile of the first member. 
     
     
         5 . A subsea tool as claimed in  claim 4 , wherein the plurality of first engagement mechanisms are provided equidistantly around the annular body member. 
     
     
         6 . A subsea tool as claimed in  claim 4 , wherein the plurality of second engagement mechanisms are provided equidistantly around the annular body member. 
     
     
         7 . A subsea tool as claimed in  claim 3 , wherein respective ones of the first and second engagement mechanisms are provided together adjacent one another, such that at designated locations around the annular body member a first engagement mechanism is provided adjacent a second engagement mechanism as a pair. 
     
     
         8 . A subsea tool as claimed in  claim 7 , wherein four pairs of first engagement mechanisms and second engagement mechanisms are provided substantially degrees apart on the annular body member. 
     
     
         9 . A subsea tool as claimed in  claim 1 , wherein the gasket has an outwardly projecting rib having an outwardly facing annular groove and/or a downwardly facing surface or groove. 
     
     
         10 . A subsea tool as claimed in  claim 9 , wherein the one or more first engagement members of the one or more first engagement mechanisms are configured to engage with the outwardly facing annular groove or downward facing surface or groove. 
     
     
         11 . A subsea tool as claimed in  claim 1 , wherein the one or more first engagement members of the one or more first engagement mechanisms are orientated to extend and retract in a first direction and one or more second engagement members of the one or more second engagement mechanisms are orientated to extend in a second direction, the first and second directions being substantially at 90 degrees to one another. 
     
     
         12 . A subsea tool as claimed in  claim 11 , further comprising a control means to control timing of the movement of the one or more first and second engagement members, whereby the one or more second engagement members are activated to extend, after extension of the one or more first engagement members. 
     
     
         13 . A subsea tool as claimed in  claim 12 , wherein the one or more first and second engagement mechanisms are hydraulically driven from a common fluid source, fluid to drive the one or more second engagement mechanisms only being available to the one or more second engagement mechanisms once the one or more first engagement mechanisms have been activated. 
     
     
         14 . A subsea tool as claimed in  claim 1 , wherein the one or more second engagement members are configured to engage an upwardly facing surface of the second member. 
     
     
         15 . A method for disengaging a first subsea member that is in contact with a subsea second member, the method comprising:
 (A) positioning a subsea tool according to  claim 1  such that its frame is around a peripheral surface of the first member;   (B) activating one or more of said first engagement mechanisms provided on the frame such that one or more engagement members engage with the peripheral surface of the first member; and   (C) activating one or more of said second engagement mechanisms provided on the frame such that one or more of the second engagement members are hydraulically driven to engage with the second member to urge the first subsea member out of contact with the second subsea member.   
     
     
         16 . A method for engaging a first member into contact with a subsea second member, the method comprising:
 a) positioning a subsea tool according to  claim 1  such that its frame is around a peripheral surface of the first member;   b) activating one or more of said first engagement mechanisms provided on the frame such that one or more engagement members engage with the peripheral surface of the first member to hold it for transport thereof;   c) activating one or more of said second engagement mechanisms provided on the frame such that one or more of the second engagement members hydraulically extend to be proud of the first member;   d) transporting the tool so as to be positioned above the second member;   e) lowering the tool so that the second engagement members land on the second member;   f) activating the one or more second engagement mechanisms to retract the second engagement members, thereby lowering the first member onto the second member;   g) activating the one or more first engagement mechanisms to retract the first engagement members to release the first member from the tool and in position on the second member.   
     
     
         17 . A method as claimed in  claim 16 , wherein steps a) and b) are carried out before the tool is subsea. 
     
     
         18 . A method as claimed in  claim 16 , wherein the tool comprises at least one downwardly depending guide arm for guiding the tool into position with respect to the second member.