They’re retired, but still relevant

Status, disposal plans updated for several pump stations no longer used to move North Slope crude oil down the trans-Alaska pipeline

Wesley Loy

For Petroleum News

As Alaska North Slope oil production has declined over the years, the operator of the trans-Alaska pipeline hasn’t needed to run as many pump stations to move the crude.

Today, only four pump stations do the main work along the 800-mile line.

Several others are, for the most part, retired.

But the retired stations aren’t entirely irrelevant. All continue to contribute something to the job of safely operating the pipeline. And they continue to consume significant dollars for maintenance, and for work toward the day when the stations could be dismantled.

The pipeline owners — BP, ConocoPhillips, ExxonMobil and Chevron — recently filed required annual updates with the Regulatory Commission of Alaska on the status of work at pump stations 2, 6, 7, 8, 10 and 12.

Alyeska Pipeline Service Co., which operates the line on behalf of the owners, has effectively disconnected most of these stations from the pipeline, and has done considerable work toward their permanent disposal.

Concurrently, the company has mounted a hugely expensive program to upgrade the four workhorse stations that today move around 550,000 barrels of oil per day. That’s a lot of oil, but far less than the peak of 2.1 million barrels seen in 1988.

Alyeska spokeswoman Michelle Egan told Petroleum News the company has conducted work such as “straight pipe” projects to route oil through idle stations, bypassing valves and other equipment.

The company has no immediate plans to remove entire pump stations, she said.

Here are a few notes from each of the six status reports the owners filed with the commission in February under docket No. P-04-021.

Pump Station 2 — This station, located toward the northern end of the pipeline, has been in “ramp down status” since 1997. The station is now permanently isolated from the main oil line, and is currently unmanned.

The station still has support equipment such as a communications module and pressure and temperature instruments.

“Preparation for final disposition remains to be done for some buildings, structures, systems and piping,” the update says. “Final disposition of these items may mean abandonment-in-place, removal for use elsewhere, salvage, or removal and disposal.”

Removal of structures and equipment is scheduled for no earlier than 2016. Asset retirement costs are estimated at $6 million to $10 million.

Pump Station 6 — This station has been in “ramp down status” since 1997, and is permanently isolated from the main oil line.

“Facilities that are currently active at this site include a refrigeration skid, vehicle fueling station, microwave communications tower, the pump station control room containing communications and control equipment, and a new communication module containing control and communication equipment,” the update says. “In addition, this site serves as an oil spill response base.”

Several buildings remain active for housing workers, and the site also serves as the base for the Yukon River bridge security detail.

“Preparation for final disposition and demolition is ongoing, with work currently planned for 2016 or later for some buildings, structures, systems and piping,” the update says.

Pump Station 7 — This station is no longer required to move crude. However, since 2011 it has played an important role in combating problematic chilling of oil inside the pipeline.

A single mainline pump at PS 7 has been configured to recirculate oil, which adds heat, the update says.

This pump will be operated in winter months when required to maintain crude temperatures above 31 degrees. The station also can assist with a “cold restart” of the pipeline.

The station will remain in service for crude oil heating until 2016, and is not currently scheduled for permanent isolation from the pipeline.

Capital improvements at the station totaled more than $12 million in 2013.

Pump Station 8 — The station has been in “ramp down status” since 1996, and is now permanently isolated from the main oil line.

Equipment such as flow meters for pipeline leak detection remains active at the station.

Future asset retirement costs are estimated at $6 million to $10 million.

Pump Station 10 — The station has been in “ramp down status” since 1996, and is now permanently isolated from the main oil line.

Work in 2013 included straight-lining the oil pipeline through the station, and draining and cleaning in preparation for demolition work.

A new generator module and a control system upgrade are planned for the station in 2014, at a total cost of up to $10 million.

Pump Station 12 — The station was permanently isolated from the main oil line in 2005-06.

The site continues as a base for spill response and cold restart equipment. A control system upgrade is planned.