I know that there are sensors used to monitor the flow of crude, and that they at least make cursory visual inspections of the pipeline, but the lack of interior inspections that I read about in the article below makes me wonder how big of an accident has been avoided, and why haven't they used the "smart pig" in the last 14 years.
BP officials said the line where the leak was found was last checked for weakness using a technology called a ''smart pig'' in which a device is sent down the tubes to assess pipeline integrity in 1992.
BP had not done a routine maintenance ''pigging'' on its transit lines because they didn't think it was necessary because those lines carry clean crude from which water was removed.
Steve Marshall, president of BP Alaska, said the company believed ultrasonic testing of pipeline wall thickness was an acceptable substitute on those lines.
In hindsight, he said, that has proven not to be sufficient.
''Clearly, we are already in the process of adjusting considerably our corrosion program,'' Marshall said, adding that the company will significantly increase its maintenance and surveillance of the transit lines both now and when they are replaced. The company is spending $72 million this year to inhibit corrosion, up from $60 million last year.
The aging pipeline system on the North Slope has been fraught with problems lately. BP, which posted a net profit of $7.3 billion for the three months ending June 30, operates the Prudhoe Bay field.
In March, BP was blamed for the rupture of a pipeline at the same Prudhoe Bay field, leading to an extension of a criminal investigation into the company's management of its Alaskan operations.
Steve Marshall, president of BP Exploration Alaska Inc., said tests Friday indicated that there were 16 anomalies in 12 areas in an oil transit line on the eastern side of Prudhoe Bay. Tests found losses in wall thickness of between 70 and 81 percent. Repair or replacement is required if there is more than an 80 percent loss