Facilities piping gas leak shuts in Northstar
Alaska North Slope production was down more than 40,000 barrels per day following shut in of the offshore Northstar field Feb. 17.
A pinhole leak was discovered in piping on the gas compression side of the facility, BP Exploration (Alaska) spokesman Daren Beaudo told Petroleum News Feb. 21.
BP is the field operator, and 98 percent working interest owner; Murphy Oil owns about 2 percent of Northstar.
Beaudo said an operator at the facility spotted an indication of a pinhole leak, a sputtering and some ice accumulation in a spot on an eight-inch discharge pipe. The piping is in one of five stages of drying out the gas before it is reinjected. Beaudo said the low-pressure system piping connects different compression and cooling processes.
Pinhole leak at a weld The pinhole was located at a weld, Beaudo said, and when workers checked other welds they found others that were thinning. The pipe is being replaced rather than repaired, he said, and BP is also inspecting other stages of the gas compression unit.
Replacements and repairs will be made and Northstar is expected to be back online the week of Feb. 26.
Production began dropping at Northstar Feb. 16, with 43,104 barrels produced that day, compared to figures typically above 47,000 bpd earlier in the month. On Feb. 17 production dropped to zero, pulling total Alaska North Slope production into the 750,000-bpd range. ANS production ranged between 780,000 and 808,000 bpd Feb. 1-16.
The field, in the Beaufort Sea some six miles north of the Prudhoe Bay field, is produced from a gravel island with oil going to shore via a subsea pipeline. Production began from Northstar in October 2001 and peaked at 80,000 barrels per day.
—Kristen Nelson
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