In response to a continuing natural gas pipeline leak under Cook Inlet, Hilcorp Alaska has shut in its Middle Ground Shoal oil field, the company said March 25. Having discovered a breach in the pipeline that supplies fuel gas to the field's offshore platforms, the company had already stopped nonessential operations on the platforms, so that the pressure in the fuel line could be minimized. Hilcorp had been reluctant to completely shut in the field. Given the cold winter conditions in the inlet, stopping the flow of oil through the subsea oil export line from the field posed the risk of the oil line freezing and thus incurring damage to the line.
"Shutting in wells and idling lines and equipment in very cold temperatures creates a known risk of freeze up and potential rupture," Hilcorp said. "Warmer ambient temperatures now permit a safer shut in process of the wells along with the associated lines and equipment."
After discussions with Gov. Bill Walker and the Alaska Department of Environmental Conservation, the parties involved agreed on a reduction of the pressure in the gas line to 65 pounds per square inch, a pressure level that necessitates shutting in oil production from the field, Hilcorp said.
The company plans to send divers down to repair the broken gas line but has not yet been able to do so because sea ice conditions in the inlet currently render diving operations unacceptably dangerous.
- ALAN BAILEY
See story in the April 2 issue, available online Friday, March 31, at www.PetroleumNews.com