Update on Trading Bay slop oil release

Kristen Nelson

Petroleum News

In a Dec. 17 situation report on the Dec. 15 slop oil release at Hilcorp Alaska’s Trading Bay production facility, the Alaska Department of Environmental Conservation’s Division of Spill Prevention and Response said Hilcorp and Cook Inlet Spill Prevention and Response Inc. personnel were on site Dec. 17 continuing to recover oil from the containment area, with 17 barrels of the 190-barrel release recovered.

The release occurred during a transfer of slop oil from Tank 4 to the slop oil tank, TK-9500. As that was occurring the operator noticed the TK-9500 tank level was not increasing proportionately to the decrease in the level of Tank 4, and after visual inspection, the operator observed oil under and around the edges of the secondary containment liner.

The division said the operator immediately isolated tank TK-9500 and the leaking line.

Hilcorp describes slop oil “as oil that includes more water than their specifications for selling that oil,” the division said, with the slop oil going through additional treatment to remove excess water, after which it put back into the oil processing system.

In a final situation report, issued Dec. 22, the division said that as of Dec. 21 115 barrels of slop oil had been recovered.

“Response personnel continue to recover oil from the containment area with a vac truck,” the division said, and Hilcorp and its contractor Chosen Construction are working to remove snow and ice in preparation to excavate the site of impacted soils and inspect the ruptured line.

The division said Dec. 21 that CISPRI personnel were being demobilized and Chosen Construction has installed heaters to thaw certain areas within the containment area.

“Once the collection of oil with a vac truck is complete, personnel will work on small sections to scrape up contaminated soil. Excavation of the compromised line is anticipated to begin soon to uncover the pipeline point of failure,” the division said, with response actions, sampling and waste disposal continuing to be coordinated with Hilcorp and DEC.

- KRISTEN NELSON