Many pile mounted jacket type fixed platforms in shallow water have been installed during the last fifty years for producing oil. However, a production platform in 165 feet of water that produces 414,000 barrels of oil and 436 million standard cubit foot of gas per day (mmscfd) is not so common. In November 2003, such a platform has been installed by PEMEX (Petroleos Mexicanos) in the AKAL-L complex of Cantarell field located in the bay of Campeche. The Cantarell field development is a very high-profile development undertaken by PEMEX at a cost of more than US $10 billion. Although it is a shallow water platform, many design considerations are quite challenging because of the methods of construction, loadout, transportation, installation, etc. For example, the production deck of this installation weighs approximately 11, 500 tonnes, including rigging. In the early stage of design, it required consideration of one-piece construction vs. multi-piece construction for cost effectiveness. The decision process included considerations of not only the capabilities of fabrication facilities, but also the availability and capacity of an installation/crane barge, such as the Saipem S-7000. The deck was finally constructed in five modules, one large 7000 tonnes module, and four smaller modules for generator and compressors each weighing approximately 900 tonnes. Proper planning of loadout, lifting operations and related engineering issues proved crucial to the successful installation of the platform. The deck of the platform was built in Dragados Offshore yard in Cadiz, Spain, and was then dry towed on a large deck cargo barge, S-44, owned by Saipem. The water level at the loadout dock site and range of tides in the area made it necessary to ground the S-44 during deck loadout. Grounding of the barge raised several engineering issues, such as, the adequacy of the barge structure during the loadout operation, preparation of the mudline at the dock, developing of a detailed ballasting sequence, inspection of barge structure before sail-away, etc. The transportation of the deck not only required proper design of seafastening structures, but also required verifying the structural integrity of the deck and other structures of the module. This paper presents an overview of the design features of the platform as well as the methods of loadout, transportation and installation.
展开▼
