Platform deck installation and removal method and apparatus

Abstract

An apparatus for loading a topside onto a jacket is provided. The apparatus may include: a projecting structure extending beyond a deck of a marine vessel wherein the projecting structure configured to support the topside and the projecting structure is dimensioned sufficiently long enough to allow the marine vessel to approach a submerged jacket and position the topside above the submerged jacket without having the marine vessel contact the jacket; and a support configured to support the topside above the projecting structure. A method for one of installing and removing a topside from a jacket may be provided. The method may include: positioning sponsons attached to a marine vessel around a jacket; supporting at least part of the weight of the topside on the sponsons; and one of attaching and detaching the topside and jacket.

1 . An apparatus for loading a topside onto a jacket comprising:
 a projecting structure extending beyond a deck of a marine vessel wherein the projecting structure is configured to support the topside in a cantilevered manner and the projecting structure is dimensioned sufficiently long enough to allow the marine vessel to approach a submerged jacket and position the topside above the submerged jacket without having the marine vessel contact the jacket; and   a support configured to support the topside above the projecting structure.   
     
     
         2 . The apparatus of  claim 1 , wherein the projecting structure includes a support beam located above the deck of the marine vessel. 
     
     
         3 . The apparatus of  claim 2 , wherein the support includes a skid shoe located on the support beam wherein the skid shoe is configured to skid across the support beam while supporting the topside thereby allowing the topside to move along the support beam. 
     
     
         4 . The apparatus of  claim 3 , further comprising a winch system located on the marine vessel configured to move the topside along the support beam. 
     
     
         5 . The apparatus of  claim 2 , further comprising a second marine vessel and a support column attached to the second marine vessel and the support beam whereby allowing the topside on the support beam to be supported by both marine vessels. 
     
     
         6 . An apparatus for loading a topside onto a jacket comprising:
 a projecting structure extending beyond a deck of a marine vessel wherein the projecting structure is configured to support the topside and the projecting structure is dimensioned sufficiently long enough to allow the marine vessel to approach a submerged jacket and position the topside above the submerged jacket without having the marine vessel contact the jacket; and   a support configured to support the topside above the projecting structure wherein the projecting structure includes a sponson attached to the marine vessel and providing buovancey to the marine vessel.   
     
     
         7 . The apparatus of  claim 6 , wherein the support includes a jack attached to the sponson and configured to be actuated to move the topside vertically with respect to the sponson. 
     
     
         8 . The apparatus of  claim 6 , wherein the sponson is a first sponson and further comprising a second sponson attached to the marine vessel and oriented alongside the first sponson and the topside is supported by both sponsons. 
     
     
         9 . The apparatus of  claim 6 , further comprising a buoyancy box attached to the sponson and configured to provide additional buoyancy to the sponson. 
     
     
         10 . A method for one of installing and removing a topside from a jacket comprising:
 locating a cantilevered support beam proximate to the jacket;   moving the topside along the support beam; and   one of attaching and detaching the topside and the jacket.   
     
     
         11 . The method of  claim 10 , further including using a skid shoe to move the topside along the support beam. 
     
     
         12 . The method of  claim 11 , further including loading a support assembly on a marine vessel, loading the topside onto the support assembly and fastening the topside and support assembly to the marine vessel. 
     
     
         13 . The method of  claim 11 , further comprising ballasting a marine vessel supporting the support beam and adjusting the ballasting of the marine vessel as the topside is one of loaded and unloaded from the marine vessel. 
     
     
         14 . The method of  claim 11 , further comprising supporting the support beam with a second marine vessel. 
     
     
         15 . A method for one of installing and removing a topside from a jacket comprising:
 positioning sponsons attached to a marine vessel around a jacket;   supporting at least part of the weight of the topside on the sponsons; and   one of attaching and detaching the topside and jacket.   
     
     
         16 . The method of  claim 15 , further comprising aligning the topside with the jacket and lowering the jacket to attach the jacket to the topside, 
     
     
         17 . The method of  claim 15 , further comprising ballasting the marine vessel supporting the support beam and adjusting the ballasting of the marine vessel as the topside is one of on loaded and off loaded from the marine vessel. 
     
     
         18 . The method of  claim 15 , further comprising raising the topside with respect to the sponsons. 
     
     
         19 . The method of  claim 15 , further comprising providing buoyancy to the sponsons with a buoyancy box. 
     
     
         20 . The method of  claim 15 , further comprising one of either attaching and reattaching the sponsons to the topside.