DESIGN AND CONSTRUCTION OF DEEP WATER JACKET PLATFORMS

Recent progress in offshore platforms is the result of step by step improvement of existing technology. The skirt pile, the gravity structure, the guyed tower, and the vertically moored platform, have all existed since World War II. Three pioneering structures of the jacket type have now been built in water depths greater than 800ft. The Cognac jacket, standing in 1025ft 90 miles south of New Orleans, is the current record holder. The design program for such an offshore platform is studied step by step in this article. Environmental loading design, with reference to hurricanes, is mentioned. Specific installation engineering and analysis problems are studied. The launch barge, for example, is a key piece of equipment in the installation. Barge stability problems preclude the use of the two sectionalized concept in deeper water. In very deep water a concept that allows the base section to be fabricated and transported in a vertical orientation is more feasible.