Floatation module and method

Abstract

An apparatus for reducing the load applied to a rig. The rig is positioned over a well, with the well having a tubular string disposed therein. A landing string is connected to the tubular string such as casing, production and/or testing assemblies. The apparatus comprises a floatation module attached to the landing string and a clamp for clamping the floatation module onto the landing string. In one embodiment, the floatation module comprises a tubular sleeve having a buoyant material applied thereto. The tubular sleeve includes slots. The clamp may contain a set of dies adapted to engage the slots of the tubular sleeve. A method of landing a work string into a sub-sea well head from a floating drilling rig is also disclosed, wherein a marine riser connects the rig to the sub-sea well head.

1 . An apparatus for reducing the load applied to a rig, the rig being positioned over, with the well having a tubular string disposed therein, the apparatus comprising:
 a landing string connected to the tubular string;   a first floatation module attached to the landing string;   clamp means for clamping the first floatation module onto the landing string.   
   
   
       2 . The apparatus of  claim 1  wherein said first floatation module comprises a tubular sleeve having buoyant material applied thereto. 
   
   
       3 . The apparatus of  claim 2  further comprising a first plurality of slots formed in the tubular sleeve that engage with the clamp means. 
   
   
       4 . The apparatus of  claim 3  wherein said tubular string is a casing string. 
   
   
       5 . The apparatus of  claim 4  wherein said tubular sleeve is constructed of aluminum and said buoyant material comprises a foam bonded to said aluminum sleeve. 
   
   
       6 . The apparatus of  claim 5  wherein said tubular sleeve comprises a first cylindrical half body and a second cylindrical half body. 
   
   
       7 . The apparatus of  claim 6  wherein said clamp means comprises a first shell attached to a second shell, and wherein said first shell and said second shell are pivotly attached to form a cylindrical member having an internal portion. 
   
   
       8 . The apparatus of  claim 7  wherein said clamp means further comprises a first set of dies adapted on the internal portion of said cylindrical member in order to engage the first plurality of slots formed in the tubular sleeve. 
   
   
       9 . The apparatus of  claim 8  wherein a second floatation module is attached to said landing string and wherein said clamp means further comprises a second set of dies adapted on the internal portion of said cylindrical member in order to engage a second plurality of slots located in said second floatation module. 
   
   
       10 . The apparatus of  claim 9  wherein said first shell comprises a latching rod and said second shell comprises a latching protrusion and wherein said latching rod is configured to engage said latching protrusion in order to latch said first shell and said second shell together. 
   
   
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