Integrity and risk assessment of offshore jacket structures

There are the common steel platforms which can be of the eight legged type, or of lightweight four-legged variety. There are also jack-up rigs which are mobile, and tension leg platforms (TLP) which float. With steel fixed platforms the jacket supports the superstructure which contains all necessary facilities. The jacket is built in a fabrication yard and if it is a large six or eight-legged jacket designed to support full production facilities, it may well have modified legs designed as floats, or additional ballast tanks may be installed, so that it can be floated out to the site.