A leaking natural gas line in the Middle Ground Shoal area of Alaska’s Cook Inlet was sealed late last week, pipeline operator Hilcorp Alaska LLC said.
“Weather and ice conditions allowed divers to begin their work on Saturday, April 8,” the company said. “A total of 12 dives were completed on the fuel gas line in order to locate the leak, then properly position, stabilize and prepare the pipeline for repair.”
The leak point was on the bottom of the pipeline, which was resting on a boulder embedded in the seafloor. Initial inspections noted the breach to be approximately 2 inches in size. The affected section of the line was lifted about 1.5 feet from the seafloor, then stabilized, allowing for closer, more careful inspection.
The actual size of the pipeline breach turned out to be three-sixteenths of an inch by three-eighths of an inch.
“Now that the leak has been stopped, over the next several days, as weather permits, further inspection and stabilization of both the oil and gas pipelines in Middle Ground Shoal will be completed,” Hilcorp said. “Neither pipeline will be returned to regular service until Hilcorp, along with state and federal regulators, agree it is safe to do so.”
The natural gas line leak was discovered in February, and at the time sea ice prevented its immediate repair. Regulators later ordered inspection of an adjacent crude oil pipeline. The leaking natural gas line necessitated the shut-in of crude oil production from the platforms served by the fuel gas line.