Floating production facilities are attractive candidates for worldwide offshore field developments and the Tension Leg Platforms (TLP's) is one of the favourable concepts. The Heidrun TLP is the biggest floating production platform ever built and the first one in concrete. This paper briefly describes the Heidrun TLP substructure including hull tethers and foundations. The description contains information about, configuration, main parameters, schedule, construction and marine operations. Further the paper shortly presents the work that has been carried out in order to develop the next generation of cost effective TLP's in deep water. The potential for further innovative developments is also covered in brief.
The Heidrun Field is located in 345 m water depth in the northern part of the Haltenbanken area, approximately 100N miles from the west coast of mid-Norway. The field is developed by Conoco Norway Inc. The Heidrun TLP is the most northern located platform and is so far operating in the deepest water in the North Sea. The recoverable reserves are estimated to some 750 millions barrels of oil and 9.35 billion m3 of gas. The oil is offloaded from the TLP through an export system and direct shuttle loading to shuttle tankers for transport to shore (see Fig. 1). The Gas is reinjected into the reservoir up until completion of Tjelbergodden methanol plant at the north west coast of Norway. The oil throughput is designed for 200.000 bbl/day. The oil production started in October 1995 whereafter Statoil became the field operator. The Aker Company Norwegian Contractor a.s. (NC) has undertaken an Engineering, Procurement, Construction and Installation (EPCI) contract for the Heidrun TLP substructure. This contract comprises the complete delivery of the hull with two Module Support Beams (MSB), including all mechanical outfitting and all marine operations related to the substructure.