Method and apparatus for replacing damaged section of a subsea pipeline without loss of product or entry of seawater

摘要

A method and apparatus for repairing a submerged pipeline. The method comprises installing a pair of hot tap tees on either side of the damaged section of pipeline, cutting a hole in the pipeline through each hot tap tee, inserting and securing plugging pigs into the pipeline, cutting and removing the damaged section of pipeline, and installing a new section of pipeline. The apparatus includes a plugging pig for use during repair of a damaged pipeline comprising a body shaft, a cup seal secured to the body shaft for engaging an interior wall of the pipeline, a cam attached to the exterior of the body shaft, a slip assembly for sliding on the cam and engaging a slip against the pipeline wall, and a control mechanism for engaging and releasing the slip from the wall.