Marine conductor pipe assembly

Claim 1

APPARATUS FOR DRILLING, COMPLETING AND WORKING OVER AN UNDERWATER WELL, SAID APPARATUS COMPRISING (A) OPERATIONAL PLATFORM MEANS POSITIONED ABOVE THE SURFACE OF A BODY OF WATER ON A VESSEL, (B) A WELL BASE POSITIONED BELOW THE SURFACE OF THE WATER AND INCLUDING SUBSTANTIALLY VERTICAL WELL BASE PIPE MEANS HAVING A LOWER PORTION THEREOF FIXEDLY ANCHORED TO THE FORMATION BELOW SAID BODY OF WATER AND A PORTION EXTENDING UPWARDLY ABOVE SAID FORMATION, (C) MARINE CONDUCTOR MEANS CONNECTIBLE AT ITS LOWER END TO THE UPPER END OF SAID WELL BASE PIPE MEANS WITH THE UPPER END OF SAID CONDUCTOR PIPE EXTENDING ABOVE THE SURFACE OF THE WATER IN THE VICINITY OF SAID OPERATIONAL PLATFORM MEANS, (D) BUOYANCY TANK MEANS SECURED TO SAID MARINE CONDUCTOR MEANS BELOW THE SURFACE OF THE WATER AND HAVING SUFFICIENT BUOYANCY TO SUPPORT A MAJOR PORTION OF THE WEIGHT OF SAID MARINE CONDUCTOR MEANS, (E) WEIGHT SUPPORT MEANS OPERATIVELY SECURED TO SAID MARINE CONDUCTOR MEANS NEAR THE UPPER END THEREOF AND TO SAID PLATFORM MEANS FOR SUPPORTING THAT PORTION OF THE WEIGHT OF SAID MARINE CONDUCTOR MEANS UNSUPPORTED BY SAID BUOYANCY TANK MEANS, (F) SAID WEIGHT MEANS CARRIED BY SAID VESSEL AND ARRANGED FOR SUBSTANTIALLY FREE VERTICAL MOVEMENT, SHEAVE MEANS SECURED TO SAID VESSEL AT A FIXED LEVEL ABOVE THE UPPERMOST POSITION OF SAID WEIGHT MEANS, CABLE MEANS HAVING ONE END THEREOF SECURED TO SAID MARINE CONDUCTOR MEANS, SAID CABLE MEANS PASSING OPERATIVELY OVER SAID SHEAVE MEANS WITH THE OTHER END OF THE CABLE MEANS SECURED TO SAID WEIGHT MEANS, SAID WEIGHT MEANS BEING FREE TO MOVE UP AND DOWN AS THE VESSEL RISES AND FALLS DUE TO WAVE ACTION (G) MOVEMENT-LIMITING MEANS POSITIONED IN CONTACT WITH SAID MOVABLE WEIGHT MEANS FOR CONFINING THE MOVEMENT OF SAID WEIGHT MEANS ALONG A SELECTED PATH, (H) SAID MOVEMENT-LIMITING MEANS COMPRISING SUBSTANTIALLY VERTICALLY-EXTENDING RIGID ELONGATED MEMBERS OF A LENGTH AT LEAST EQUAL TO THE MAXIMUM VERTICAL MOVEMENT OF SAID WEIGHT MEANS AND ARRANGED IN CONTACT WITH SAID WEIGHT MEANS TO PREVENT ANY SUBSTANTIAL LATERAL MOVEMENT THEREOF, AND (I) SAID WEIGHT MEANS COMPRISING VARIABLE WEIGHT TANK MEANS ADAPTED TO CONTAIN WEIGHTING MATERIAL.