By OGJ editors
HOUSTON, Sept. 18 -- BP PLC plans to retrieve and rebuild all seabed production equipment from Thunder Horse field in the deepwater Gulf of Mexico following a series of tests in 4 months that showed metallurgical failure.
Consequently, BP does not expect production from Thunder Horse to begin before mid-2008. The company said it's too early to estimate the additional costs involved in replacing the affected systems.
The original projected start up was for late 2005, but it has been pushed back as BP has resolved "technology gaps" that emerged during development, a spokesman said.
Thunder Horse field was discovered in 1999. The project involves some of the highest-temperature, highest-pressure wells in the gulf.
The semisubmersible platform weighs more than 50,000 tons and is designed to process 250,000 b/d of oil and 200 MMscfd of gas. BP operates the development, owning 75% interest, and ExxonMobil Corp. owns the remaining interest.
The platform had to be restored to normal trim last year. That incident is unrelated to the latest subsea equipment issues, BP said (OGJ, July 25, 2005, Newsletter).
The drilling, production, and quarters platform on Mississippi Canyon Block 778 in the Gulf of Mexico, 150 miles southeast of New Orleans, was discovered listing 20-30° after Hurricane Dennis passed through the area (OGJ Online, July 12, 2005). The platform is moored in 6,050 ft of water.
The metallurgical problems became evident when BP conducted precommissioning tests by pumping water through the system to establish its integrity. The equipment passed all normal industry standard tests and regulatory requirements, but during more-rigorous and prolonged testing, a failure occurred on a subsea weld.
Consequently, BP opted to retrieve both the damaged seabed manifold and a second manifold for additional examination and testing. The second manifold displayed a similar failure during testing last week, BP said Sept. 18.