BlueCrest amends Hansen discharge plan

Kristen Nelson

Petroleum News

BlueCrest Alaska Operating has applied to the Alaska Department of Environmental Conservation to amend its oil discharge prevention and contingency plan for its Hansen field, the Cosmopolitan project, on the Kenai Peninsula.

DEC said in a notice of the application that the current plan addresses spill prevention and response measures to support a maximum of 1,500 barrels per day of oil at the wellhead for a total discharge volume of 22,500 barrels over 15 days and a 300-barrel response planning standard for oil storage tanks. Based on information available on expected reservoir pressures when the plan was approved in 2015, DEC said there was no expected aerial blowout plume from a loss of well control event and oil from a blowout was expected to be contained within pad boundaries. No water response plans were included, and land recovery included only removal of oil from the existing pad.

“Following recent well workover operations the well pressures have increased substantially,” DEC said. An update blowout plume model was developed, which indicates potential for a significant aerial plume that could carry some 15,000 feet from the wellhead, with the potential for off-pad migration and deposition to the shoreline and waters of Cook Inlet.

However, based on current and expected production rates the response planning standard has been reduced from 1,500 bpd to 1,000 bpd for a total discharge volume of 15,000 barrels over 15 days.

In its application BlueCrest told DEC that in addition to addressing a reduction in the response planning standard, the amendment also reflects a change in the gas-to-oil ratio from 300 standard cubic feet of gas per barrel of oil to 10,000 standard cubic feet of gas per barrel. The company said that while it was reducing the response planning standard, “the increase in gas capacity results in a different plume size along with the associated potential environmental impacts, response strategies and tactics than previously modeled.”

- KRISTEN NELSON