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Pipe fails at BPXA’s Lisburne facility Spill not expected to affect oil production from Alaska’s North Slope; breach came during pressure test of newly installed valves Wesley Loy For Petroleum News
Little if any significant production impact was expected to result from a pipeline spill reported July 16 at BP’s Lisburne facility on Alaska’s North Slope.
BP Exploration (Alaska) Inc. estimated 50 to 100 barrels of methanol and produced fluids, including an undetermined volume of crude oil, spilled onto a gravel pad and into a freshwater tundra pond.
The spill was said to consist of 60 percent methanol and 40 percent produced fluids.
An 8-inch line in a piping system known as a header ruptured underground at a roadway crossing at the L-1 drill site, situation reports from the Alaska Department of Environmental Conservation said. The spilled fluids came out either end of a casing through which the ruptured pipe passes.
The line is used to divert production from wells to a test separator required by regulation, not to transport production to the Lisburne processing facility, BP said.
The pipe failure occurred during a hydrostatic pressure test intended to check newly installed valves.
The line failed after pressure reached 949 psi, the situation reports said. It reportedly was rated for considerably higher pressure, but BPXA spokeswoman Dawn Patience couldn’t specify how high.
Incident under investigation The Lisburne field is a reservoir located within the BP-operated Prudhoe Bay unit. Lisburne began production in 1986.
BPXA subcontractor employees discovered the spill at 3:28 a.m. July 16. The spill was reported to the Alaska State Troopers at 4:05 a.m., the DEC situation reports said.
Spill responders laid boom, and vacuum trucks recovered 15 barrels of spilled liquids from the tundra.
About 2,040 square feet of wet tundra and 4,960 square feet of gravel pad were affected, the situation report said.
The Lisburne facility had been shut down for maintenance for about a month, and so no production loss was experienced, Patience said.
“While the L-1 drill site will remain shut-in, this incident will not delay the restart condition for the Lisburne Production Center,” the DEC said.
The cause of the pipeline failure, and whether corrosion was a factor, remained under investigation, Patience said. Corrosion has been a well-publicized issue for BP since a pair of major oil transit lines sprang leaks in the Prudhoe Bay field in 2006.
“It would be preemptive to the investigation of the L-1 incident to speculate on a cause,” Patience said in a July 19 e-mail to Petroleum News. “This investigation is already underway and we will share the results with regulators.”
Patience added: “The pressure test was continuously monitored and the spill was detected immediately. The test was terminated and spill response was initiated. The test we were undertaking was in fact an integrity inspection of the pipe and its components. Hydrostatic pressure testing is a common and accepted method for integrity testing and is one of the ways a prudent operator ensures safe and reliable pipeline operations.”
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