Alyeska plans to end West Tank Farm use

Four tanks at Valdez Marine Terminal are empty, disconnected from line; removing lids would improve safety, reduce operating costs

Kristen Nelson

Petroleum News

The volume of Alaska North Slope crude oil passing through the Valdez Marine Terminal is less than quarter of what it was at the peak of ANS production in the 1980s, and fewer tanks are needed to store oil prior to tanker loading.

The major trans-Alaska oil pipeline owners - BP Pipelines (Alaska) Inc., ConocoPhillips Transportation Alaska Inc. and ExxonMobil Pipeline Co. - have applied to the Regulatory Commission of Alaska to permanently discontinue use of the West Tank Farm at Valdez.

In a Dec. 5 filing the three major owners (Unocal Pipeline Co. is in the process of completing transfer of its minor interest to the remaining owners) told the commission the four tanks at the West Tank Farm are no longer needed to support the transportation service provided by the trans-Alaska oil pipeline.

The Valdez Marine Terminal has two tank farms, and the 14 tanks at the East Tank Farm are capable of storing 7 million barrels of oil; the West Tank Farm, when it was operational, could store 2 million barrels.

The owners said permanent removal of the West Tank Farm from service would reduce current and future operating and maintenance costs at the VMT, and eliminate capital investment costs that would otherwise be necessary to maintain the West Tank Farm.

Costs associated with the West Tank Farm include the cost of removing snow from the tank roofs.

Should the West Tank Farm not be permanently removed from service, changes would be required to its industrial wastewater system to satisfy Alaska Department of Environmental Conservation environmental regulations, alternations which would “require substantial capital investment.”

The owners said DEC has agreed that if the West Tank Farm is taken out of service, alterations to its industrial wastewater system would be unnecessary.

Costs associated with the permanent discontinuance of use of the West Tank Farm would not increase trans-Alaska pipeline system intrastate rates, the owners said.

In addition to economic benefits, permanently removing the West Tank Farm from service would simplify VMT operations and reduce personnel safety risks.

“Snow is manually removed from the tank roofs each winter to avoid the potential tank top deformation and structural failure of the tanks that might result from the heavy snow loads that are common in Valdez,” the owners said.

If the commission approves the application, “the roofs will be removed from the four West Tank Farm tanks, obviating the need for snow removal and eliminating the risks inherent in having personnel perform the snow removal tasks.”

With approval of the application, the owners said they would authorize Alyeska Pipeline Service Co., which operates the pipeline and the VMT for the owners, to begin work necessary for removal of the roofs during the 2015 summer construction season. To allow planning and preparation work, the owners are requesting approval of the application by April 15.

The four West Tank Farm tanks are empty, the owners said, “all recoverable tank bottoms have been removed, and the tank valves have been removed with blind flanges installed in their place.”

In addition, “each tank has been totally isolated from the crude piping previously connecting the tanks to crude oil manifolds, and the piping has been cleaned and capped to eliminate deadlegs.”

With application approval, the owners said, roof removal is expected to begin in late May.

“Removal of the tank roofs will reduce personnel safety risks associated with winter snow removal activities and will further reduce VMT operating and maintenance costs,” the owners said. “It will also serve to simplify operations at VMT.”