The trans-Alaska oil pipeline is buzzing with activity. It's the fallout from an early 2011 spill at Pump Station 1 that forced extended shutdowns of the line and drew intense scrutiny from federal regulators.
The work, which involves rearranging station pipes and installing measures to help the pipeline better cope with extreme cold weather and cooling crude temperatures, approaches a budget of $200 million, Alyeska spokeswoman Michelle Egan told Petroleum News.
A "consent agreement" Alyeska signed with regulators is guiding the work. It's essentially a long to-do list stemming from the Pump Station 1 incident.
The Jan. 8, 2011, discovery of spilled oil in the basement of a booster pump building at the station forced two shutdowns extending over several days.
On Feb. 1, 2011, the U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration hit Alyeska with notice saying that as the result of an investigation, "it appears that multiple conditions exist on your pipeline facility that pose a pipeline integrity risk to public safety, property or the environment."
The notice focused on the pipeline's declining oil throughput, cooling crude temperatures and the potential for a pipeline freeze-up during a winter shutdown.
PHMSA also raised concerns about inaccessible, below-ground station piping of the sort that leaked at Pump Station 1.
The ensuing consent agreement between the agency and Alyeska, reached in August 2011, laid out extensive work that Alyeska is busy trying to complete.
A recent Alyeska update to PHMSA, dated Jan. 14, described some of this work.
At Pump Station 1, major work is under way to replace below-ground piping. Alyeska also plans to replace below-ground piping at several other pump stations along the 800-mile line.
In November, Alyeska installed and tested a new mainline pump engine at Pump Station 12, the update said. The pump and engine are meant to enhance the pipeline's cold restart capability.
Alyeska also finished "enhanced recirculation" projects at Pump Station 4 and Pump Station 7 in December. The projects involved changing out values or making other adjustments to run oil through the pump stations more than once, which Alyeska has found to be an effective way to add heat to the crude.
PHMSA inspectors have been visiting some of the work sites.
To date, the agency has not levied any fines against Alyeska for the 2011 spill and pipeline shutdowns.
Under the consent agreement, Alyeska is to replace or remove any piping along the pipeline system that can't be assessed with pigs and would, upon failure, compromise the safe operation of the pipeline.
Pigs are tools that move through a pipeline to check for problems such as corrosion.
Egan, the Alyeska spokeswoman, said the volume of work "is very significant and has been in the planning stages for several years."
The work to bring Pump Station 1 piping above ground is something that was in Alyeska's project plan even before the 2011 leak, she said.
"The benefit of elevating the piping at that station is to make it fully inspectable," Egan said.
She noted that the piping work coincides with the electrification and automation of Pump Station 1. It's the last station to undergo such a makeover in a long-running program Alyeska once referred to as "strategic reconfiguration."
The trans-Alaska pipeline has been moving North Slope crude oil since 1977. Alyeska runs the pipeline on behalf of the owners including BP, ConocoPhillips and ExxonMobil.