Faulty subsea equipment delays Tahiti

A third major field development in the deepwater Gulf of Mexico, Chevron’s $3.5 billion Tahiti project in Green Canyon, has been delayed because of problems associated with subsea equipment. Thunder Horse, Atlantis and now Tahiti represent billions of dollars in investment and hundreds of millions of barrels in stranded reserves.

Tahiti startup was delayed because of “metallurgical problems” discovered in the facility’s mooring shackles, Tahiti operator Chevron said June 28, adding that the company was in the process of ordering new shackles.

However, Chevron cautioned that replacing the shackles depended on “the ability of the company to secure replacement parts at commercially reasonable prices in a timely manner (and) the ability of the company’s contractor to install such parts in the timeframe required by the company.”

Tahiti is about 140 miles offshore and 190 miles south of New Orleans. It was scheduled for completion in mid-2008, with maximum production of 125,000 barrels of oil per day and 70 million cubic feet of natural gas per day.

Steel shackles are used to connect various components of a mooring line together. Mooring lines connect the spar to anchors on the seafloor. But the shackles are not part of the spar hull, “so this issue does not impact the spar’s integrity,” Chevron said.

“Major components of the project are nearing completion and work on their installation is expected to continue once timing for new shackles is determined,” the company added.

Initial quality control testing of Tahiti’s existing shackles did not identify a problem, Chevron said, noting that additional testing was then ordered after Chevron’s contractor discovered a “metallurgical problem” with shackles on a similar installation for another company. “Metallurgical problems were subsequently discovered in the Tahiti shackles as well,” Chevron said.

Last September BP announced that startup of its huge Thunder Horse field was delayed until mid-2008 because of “metallurgical failure” in components of the field’s subsea system. BP then decided to replace Atlantis’ subsea equipment, postponing startup of that field until sometime this year.

—Ray Tyson