Corrosion

A federal appeals court in Washington, DC, has rejected a motion by the Environmental Protection Agency (EPA) to dismiss a case brought by independent producers alleging that the agency failed to go through the proper channels to regulate diesel fuel used in the hydraulic fracturing (fracking) process.

El Paso Natural Gas Co. said there was no evidence of corrosion, weld defects, prior gas leakage or slow-developing cracks in the “branch” or “tap” connection of a pipeline that ruptured and exploded Nov. 5 in Bushland, TX. “Instead, we learned the rupture was the result of an upward force on the branch connection that put pressure on a small area on the carrier pipe that contained a ‘lamination.’ The force on the lamination caused a fracture to develop in the lamination near the weld of the branch connection to the carrier pipe, resulting in the rupture,” El Paso said. A lamination is a tiny area of separation within a pipe wall where the metal has not properly bonded to itself, and the lamination feature was not a defect under the regulations of the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration, the company said. Stress Engineering Services Inc. conducted the metallurgical analysis; “We don’t know yet what caused the upward force on the branch connection,” El Paso said. Information about the investigation is at www.elpaso.com/bushlandinfo.

About 1 Bcf/d of NOVA capacity will be cut from May 31 to June9 as part of the system is inspected for stress corrosion crackingwhile tie-ins and other maintenance are performed. NOVA will take100 miles of 36-inch line between the Miekle River and Knightcompressor stations in northwest Alberta out of service during thattime. NOVA normally moves a total of about 11.8 Bcf/d, a spokesmansaid.