Abstract: A self-elevating offshore structure supports a deck for production operations at sea in the absence of an elevating hull. A non-buoyant deck is supported by braces and truss legs above wave action. The legs move in relation to the legs and the braces, elevating the deck and the braces supporting the deck. The offshore structure is transported to a deployment site by a buoyant vessel and then released from the vessel once the legs are embedded into the sea bottom.

Abstract: A self-elevating drilling unit has dual cantilever assemblies that move longitudinally and transversely in relation to the jack-up platform to allow drilling operation to be performed from two drilling floors. The twin cantilever assemblies permit simultaneous drilling on an 8 feet×8 feet spacing. The cantilever assemblies are retained attached to the platform by a hold down beam that extends over and across the cantilever assemblies. The hold down beam is positioned in a stationary manner on the platform deck. A movable strut that engages the underside of the hold down beam moves along the beam to counteract upward bending forces acting on the beam when the cantilever assemblies are extended from the platform. The cantilever assemblies are made of tubular truss work and can be moved to an infinite number of horizontal positions.