Alyeska schedules two summer maintenance shutdowns

Petroleum News

The trans-Alaska pipeline, shut down at 6 a.m. July 10 for maintenance, was restarted at 1:30 p.m. July 11.

Alyeska Pipeline Service Co., which operates the pipeline on behalf of its owners, said it completed dozens of maintenance projects from Pump Station 1 at Prudhoe Bay to the Valdez Marine Terminal during the shutdown, which lasted approximately 30 hours.

The company said some of the most extensive work was a project at Pump Station 4, where a crew of more than 100 workers replaced two valves used to launch the pigs that perform a variety of tasks in the pipeline from cleaning pipe walls to detecting anomalies.

The F427 project also took “an orchestrated coordination of manpower and machinery,” Alyeska said. Four crews set limit switches on valves at 10 sites along the pipeline. The limit switches, the company said, “assure valves open and close properly, shutting off or resuming the flow of oil upon command.”

At Pump Station 3, crews changed out three valves associated with natural gas distribution, which is used to power pumps at stations 1, 3 and 4. The valves were replaced, Alyeska said, because they were nearing “completion of their natural life cycle.”

There are line-wide shutdowns nearly every summer, allowing crews to work on projects along the pipeline, the company said. The July shutdown was scheduled to coincide with routine maintenance by North Slope producers of equipment and facilities. Crude oil shipment continued during the shutdown, with loading from storage tanks at the terminal.

Alyeska said a second shutdown, Aug. 16-17, is for preparatory work for electrification at some of the pump stations as part of the company’s $250 million strategic reconfiguration.