Method for extending an extensively draft platform for offshore oil and gas production

摘要

"METHOD FOR EXTENDING AN EXTENSIBLE DRAFT PLATFORM FOR OFF-COAST OIL AND GAS PRODUCTION". An extension of an offshore oil and gas production platform comprises placing a floating equipment deck on a pontoon so that the elongated legs on the pontoon, each comprising a float, extend movably through respective openings in the deck. . Chains extending from the winches over the deck are passed through pontoon tips and connected back to the deck. Chains are extended to secure the deck to the pontoon for joint movement to an offshore location. The chains are loosened and the pontoon and the floats are ballasted so that the pontoon and the floats sink below the floating deck. The chains are then tightened until latches on the leg floats fit the deck. The buoyancy of at least one of the pontoon and buoys is increased so that the deck is thereby raised above the water surface. Chains are connected to mooring lines around an offshore pit site, and the raised deck and sunken pontoon are held in a selected position over the site with winches.