Federal agency orders Hilcorp to replace pipeline that has leaked natural gas into Cook Inlet several times

Published: Apr. 8, 2021 at 3:09 PM AKDT
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ANCHORAGE, Alaska (KTUU) - A federal agency has ordered oil and gas company Hilcorp to repair and then replace an approximately 7-mile stretch of pipeline, which leaked natural gas into Cook Inlet earlier this month for the fifth time since 2014.

Hilcorp reported the leak to the Alaska Department of Environmental Conservation last week after a helicopter pilot saw bubbles on the surface of Cook Inlet waters while flying overhead.

At that time, an unknown amount of transmission-quality gas — 98% methane — was leaked into Cook Inlet until Hilcorp activated block valves and shut in the pipeline on April 3. The 8-inch pipeline carries the gas to power two offshore platforms — the 7-mile segment with the current leak runs from an onshore facility near Nikiski out to Hilcorp’s Platform A.

The Pipeline and Hazardous Materials Safety Administration originally issued Hilcorp a corrective action order on April 3, two days after the leak was reported.

According to a 12-page amended corrective action order issued Tuesday, Hilcorp originally told the agency that shutting in the pipeline posed a potential risk of causing a crude oil leak in another pipeline because the natural gas pipeline fuels boilers and powers the offshore platforms.

Hilcorp originally reported that it would not be able to get alternative heat sources to the platform in a timely manner in order to continue flowing water through the crude-oil line so that it wouldn’t freeze. The federal agency’s first corrective action order did not require Hilcorp to shut in its leaking natural gas pipeline — only to reduce the pressure.

The shut-in happened on April 3 when Hilcorp discovered a pressure drop and an increase in flow in the natural gas pipeline, according to the amended order. It was as a result of this change that Hilcorp shut-in and blocked the pipeline.

Now, the oil and gas company has until April 17 to temporarily repair the affected segment running between the onshore facility and the platform, and until May 1 to completely repair it, according to the amended order.

Hilcorp has one year to replace the pipeline entirely.

According to the order, the leak, which is estimated to be a quarter inch hole in the pipeline, spilled between 75,000 and 150,000 cubic feet of natural gas into Cook Inlet per day.

Associate Administrator Alan Mayberry wrote in the order that the pipeline leak “occurred in an ecologically sensitive area and presents a serious risk to the environment due to the presence of several endangered and threatened species.”

Those include Cook Inlet’s beluga whale population.

Last week’s leak is the fifth since 2014 for this particular pipeline, according to the order. The line leaked twice in 2014 before Hilcorp purchased the facilities in 2015.

The pipeline experienced a major leak between December 2016 and May 2017, when winter and ice conditions prevented Hilcorp from repairing it, and again in 2019 when a leak was discovered through an inspection. Three of those previous leaks were caused by rocks coming into contact with the pipeline, while the 2019 leak was caused by corrosion and weld discontinuity, the order states.

In the amended order, Mayberry wrote that he considered several factors in ordering the pipeline to be replaced, including its age and construction, the proximity of the pipeline to environmentally sensitive areas, the hazardous nature of the natural gas it transports and its history of leaks.

“I find that continued operation of the (pipeline) ... without corrective measures is or would be hazardous to life, property, or the environment, and that failure to issue this Amended Order expeditiously would result in the likelihood of serious harm,” Mayberry wrote.

Hilcorp did not respond to requests for comment in time for this article. The company has 10 days from the time the amended order was issued to request a hearing. Hilcorp can also request time extensions through written request.

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