By OGJ editors
HOUSTON, Nov. 11 -- The US Minerals Management Service has approved the first permanent use of synthetic moorings to anchor a platform to the seabed in deep water. The action came Nov. 7 during a preliminary review of BP PLC's deepwater operations plan (DWOP) for the development of Mad Dog field in the Gulf of Mexico. Project owners are BP 63.56%, Unocal Corp. 25%, and BHP Petroleum (Americas) Inc. 11.44%.
Mad Dog, which has estimated reserves of 400 million boe, is on a $1 billion fast-track development schedule to produce first oil at the end of 2004 (OGJ, June 17, 2002, p. 22). To this end, BP will install a truss spar employing dry tree wells and the first permanent use in the gulf of synthetic moorings at the field, which lies on Green Canyon Block 826 in 4,420 ft of water.
The moorings consist of high-strength polyester fibers that provide protection equal to or greater than that provided by steel wire rope systems while reducing the vertical loads on the spar hull, MMS said. The truss spar is held on location by an 11-line polyester taut-leg mooring configuration.
"This approval is an excellent example of how MMS can work with industry to enable the use of new cost-effective technology while providing for safety and meeting MMS's regulatory responsibilities," said MMS Director Johnnie Burton.
MMS said it became convinced of the safety and reliability of this approach after participating in extensive testing and a total system engineering review, emphasizing operational safety, environmental protection, and conservation of resources.
Previously MMS had participated in nine joint industry projects (JIPs) and studies on synthetic moorings, directing $765,000 in research funding towards this effort. As part of the JIPs, MMS worked with the UK's National Engineering Laboratory to study fatigue of polyester moorings and to evaluate the long-term durability of fiber ropes in a marine environment.
In addition, MMS participated in and sponsored three workshops to increase the understanding and practical use of synthetic moorings worldwide. These JIPs and workshops were instrumental in the development of American Petroleum Institute's Recommended Practice "(RP) 2SM (Synthetic Mooring)" as an industry-wide recommended practice for the use of synthetic moorings.