Alyeska Pipeline Service Co. has twice "lost" pigs in the trans-Alaska pipeline in the past two years, says a report by a longtime independent oil industry analyst. Richard Fineberg says the pigs, used for cleaning or collecting data in the pipeline, ended up damaged and stuck in relief piping systems. In one case it took a week to find the pig, says the report covered today in the Fairbanks Daily News-Miner.
[Fineberg] said the pressure changes in the line caused a cleaning pig to be pulled backward "into the smaller diameter discharge relief piping, where damaged pig parts were found blocking the relief line one week later."
He said the incident was not covered by reporters and the public was not informed about the incident. Subsequent reports by the State Pipeline Coordinator's Office said the pressure relief system piping sustained extensive damage.
A second pig was lost in May 2012 at Valdez and parts of the machine also ended up in relief system piping.
Read more, and see a photo of a damaged pig, at the News-Miner: Oil industry researcher says Alyeska lost two pigs in two years