The scope of work should include complete removal of the deck, jacket and piling structures by cutting the piles at a minimum of 5 feet below the mud lines using internal / external abrasive cutting method(s). Once the structure is severed from the piles it can be removed by lifting using a crane barge (lifting capacity depending on the type and weight of each structure). Typically, the riser(s) should be removed together with the jackets, while the deck removal will require a separate lift before the pile severing. For some platforms, the deck removal may be performed even earlier during the flare line flushing phase.
After jacket removal, the sea bottom will need to be scanned to identify any dropped objects and debris to be removed by diver assisted lifting. The goal is to return the sea bed to a condition that will not hinder other users. No major man-made objects should be allowed to remain in place except the piles and the abandon pipelines with an elevation of at least 3 ft. below the mud line.