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Chevron restarts Cook Inlet platform Production from Anna tops 1,000 barrels of oil per day after operator completes repair of corroded riser on nearby Bruce platform Wesley Loy For Petroleum News
Chevron has repaired a corroded pipeline riser and placed its Anna platform in Alaska’s Cook Inlet back on production.
“We started shipping oil from the Anna on June 12,” company spokeswoman Roxanne Sinz told Petroleum News via e-mail on July 9.
The Anna platform, southwest of the village of Tyonek, has averaged 1,030 barrels per day since the restart, Sinz said.
Shipping resumed after a “composite pipeline repair of the riser” was installed, says a Chevron letter dated June 18 to the U.S. Pipeline and Hazardous Materials Safety Administration. The letter was posted July 6 on a federal website.
The letter says PHMSA officials witnessed the repair and approved restarting operation of the pipeline.
The pipeline and riser carry production from the Anna platform to the neighboring Bruce platform. From there, oil goes to the onshore Granite Point production facility.
Permit denial, and a fix The issue was a corrosion “feature” on the 12-inch riser, which is inside a leg of the Bruce platform.
Chevron’s subsidiary, Union Oil Company of California, had asked PHMSA for a special permit to waive compliance with pipeline safety regulations.
Corrosion had partially eaten through the riser wall, but Chevron asserted the remaining wall thickness was more than sufficient to handle the low operating pressures, and the riser had years of service life left. The company also noted the inaccessible location of the corrosion feature would make it difficult to fix.
The riser was installed in 1967, and Chevron said no leaks had been reported during its lifetime.
A state agency, the Petroleum Systems Integrity Office, opposed Chevron’s request for the repair waiver, saying “Alaska is under a national environmental microscope” and that “the political and environmental ramifications of a spill in Cook Inlet are grave.”
PHMSA ultimately denied the special permit with an April 27 letter. The agency shopped short of ordering Chevron to cease production from Anna, but said that continuing to operate the riser meant the company was “potentially subject to enforcement action.”
Chevron elected to immediately stop using the line by ceasing production from the Anna platform.
In the June 18 letter to PHMSA, Chevron’s Alaska oil and gas operations manager, Dale Haines, said the pipeline riser “is now fully remediated.”
The letter continues: “PHMSA was consulted throughout the repair process, and PHMSA personnel traveled to the Bruce Platform to witness the repair process. By the morning of June 11, 2010, the repair had properly cured, and the pipeline was ready to return to service.”
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