Method and apparatus for skid-off drilling

Abstract

A different approach to tender assisted drilling which has the flexibility to be used with multiple jack-up rigs, and nearly any type of fixed offshore production platform. A skid base includes distinct capping beam feet and skid-off feet, the former adjustable to capping beam spacing and the latter restricted to support of the skid base upon cantilever beams. A special swivel mechanism and sliding mounting in the capping beam feet, and a vertical jack in the aft skid-off feet, enable the skid base to be transferred to the fixed platform simply by aligning them over the capping beams and depressurizing the skid-off feet. Thus, walking mechanisms may be swivelled and oriented upon the capping beams, notwithstanding relative movement between the jack-up rig and the platform. The skid base is simply walked across from the cantilever beams to the platform. The drill floor package is installed onto the skid base by raising and locking the cantilever beams into alignment with the skid base, while the skid base remains in a floating condition upon the fixed platform, and by skidding the drill floor package atop the skid base. The skid base may then be uncoupled from the cantilever and aligned with the platform using the walking and swivel mechanisms and the sliding mountings of the capping beam feet. Longitudinal and transverse movement abilities of the drill floor permit tender-assist drilling upon a variety of precise locations of the platform, and is readily supported from the jack-up rig with the aid of modular piping.