More Prudhoe Bay infrastructure upgrades
Inspections and upgrades of pipelines and other infrastructure continue in the Prudhoe Bay field on Alaska’s North Slope, following some major pipeline replacements after pipeline corrosion caused an oil spill in 2006.
BP spokeswoman Dawn Patience told Petroleum News in a July 26 email that BP uses x-ray equipment, ultrasound and visual inspections as part of an on-going program to ensure pipeline integrity.
“BP has a measurable safety and reliability program for pipeline assurance on the North Slope,” Patience said. “It includes frequent inspections and applied technology. … BP does more than 110,000 inspections for corrosion under (pipeline) insulation and about 160,000 total pipeline inspections a year.”
Pipeline work According to BP’s latest Prudhoe Bay plan of development some pipeline replacement has continued, with the replacement of one of the pipelines in the field and the replacement of a fuel gas line in 2012. The company has also been doing pipeline inspections using pigs, the cylindrical devices that are passed down the insides of the lines — the company inspected four oil sales pipelines, 16 three-phase cross-country pipelines, five produced water injection pipelines, one seawater injection pipeline and three natural gas pipelines in 2012, the plan says. And most of the scheduled follow-up work for pipeline anomalies identified from similar inspections in the past two years has been completed, the plan says.
Work is also in progress to make it possible to do inspections with pigs in some other lines where pigs could not previously be used, the plan says.
Infrared technology Patience said that for a number of years BP has been monitoring pipelines from the air using infrared technology that can detect hydrocarbon vapor and temperature anomalies. The company has recently developed a means of fitting the infrared equipment on security vehicles, thus enabling ground-based infra-red monitoring, including the monitoring of areas of pipelines not visible from a vehicle cab and monitoring during variable weather conditions, Patience said. Infrared and video images from inspections are downloaded into a computer-based geographic information system, she said.
According to the development plan BP has also been upgrading the seawater treatment plant that provides water for injection into the Prudhoe Bay reservoir — the injected water maintains reservoir pressure and flushes oil from the reservoir rock. Upgrades have improved the reliability of the plant, reduced downtime and enabled better management of dissolved oxygen levels in the water, the plan says.
—Alan Bailey
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