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Hilcorp has flow line spill at Milne Quarter-inch hole in 10-inch line found Feb. 28; flow stopped, wells shut-in; bypass line installed; cleanup of pad, tundra begun Kristen Nelson Petroleum News
New Milne Point field operator Hilcorp Alaska had a produced fluids release Feb. 28 from a hole on the bottom of a Tract 14 production flowline.
A statement from the unified command for the release - Hilcorp Alaska, the Alaska Department of Environmental Conservation and the U.S. Environmental Protection Agency - said the source of the leak was a quarter-inch hole in a 10-inch diameter flow line.
DEC’s Division of Spill Prevention and Response said in situation reports that the release was observed at 7:50 a.m., Feb. 28. The cause of the production line rupture is under investigation.
Hilcorp spokeswoman Lori Nelson told Petroleum News that the line was installed in 2009. Hilcorp acquired 50 percent of BP’s interest in Milne Point and took over as operator when the sale closed in November.
Tract 14 production line The division said the incident was in a Milne Point Tract 14 production line, approximately 25 miles northwest of Deadhorse and 40 miles northeast of Nuiqsut, with an unknown amount of produced fluids, including crude oil and produced water released to the pad and tundra.
Tract 14 wells were shut-in, production flow stopped and the 15-foot segment of pipe containing the hole was isolated by shutting valves on either side of the hole. In a situation report issued the afternoon of March 3, SPAR said pressure inside the pipe segment was zero and that remaining product in the affected segment of pipe had been removed.
A wooden plug was inserted into the hole and that portion of the pipe wrapped to prevent further release, with containment supplies placed under the release point to reduce further environmental impact.
Production re-established SPAR said in its March 3 situation report that crews were able to install a bypass line and re-establish normal production levels from Tract 14 wells, eliminating the risk of freeze up in the pipeline and further protecting the environment from additional spills.
Mechanical equipment and hand tools were used to clear snow and ice. Weather on the North Slope created cleanup difficulties and responders sprayed water onto the area affected by the spill to form an ice cap, preventing further migration from blizzard conditions.
SPAR said the ice cap would not interfere with recovery of product from the site.
An estimated 3,906 gallons, 93 barrels, of liquids had been recovered by vacuum truck by March 3. Some 96 cubic yards of impacted snow was removed and staged in containers for final removal and disposal.
Product volume estimates include impacted snow, ice and released product, so an actual volume of fluids released from the pipeline is unknown, SPAR said.
Recovering product Some 38,800 square feet of gravel pad and tundra were heavily to lightly misted by fluids and the focus now is on continuing to recover spilled product from the pad and tundra. Tactics may include mechanical and hand tool removal, vacuum truck, tundra washing and collecting tundra washing water for disposal.
SPAR said there are no reports of impacted wildlife, but as a precaution, wildlife fencing has been erected to keep wildlife out of the impacted area, with wildlife hazing permits and hazing personnel activated to further deter wildlife.
The affected 15-foot pipeline segment has been emptied and the damaged portion will be removed for further inspection and analysis.
A process will be determined to estimate the amount of fluids released from the pipeline and until then the amount of affected materials recovered, including snow, ice and released fluids, will continue to be reported.
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