Sludge, lack of testing cited in pipeline failure

WASHINGTON – The North Slope oil pipelines being shut down because of corrosion were clogged for years by sludge buildup that may have prevented the most sophisticated internal corrosion tests, officials said Monday.

The last time the pipelines were cleaned and tested, using a “smart pig”
Investigators have been told that the Alaska pipeline, which sends oil from the feeder lines to the port of Valdez, conducts operations to clean line sludge every two weeks.

In Anchorage, BP Alaska President Steve Marshall said the company believed that ultrasound tests were an adequate substitute and that the “smart pig” tests weren’t necessary. He acknowledged in hindsight that was not sufficient.

AP