NEW YORK, July 2 (Reuters) - A routine shutdown for maintenance on the Trans Alaskan Pipeline System helped push U.S. oil inventories lower last week, an analyst at the Energy Information Administration said.
"That's certainly part of it," the oil and natural gas analyst at the EIA, the statistics branch of the Department of Energy, said about the shutdown. "How much of a role it played we're not sure."
Traders had been puzzled by weekly U.S. petroleum numbers the EIA published on Wednesday that showed oil inventories fell last week by a larger-than-expected 3.7 million barrels, despite slightly lower refinery runs and imports that rose a bit.
The draw was heavy on the West Coast, which operates as a separate market and receives oil from Alaska.
Alyeska Pipeline Service Co, operator of the 800-mile (1300 km) pipeline, said last month it had scheduled maintenance starting on June 20 that was expected to last up to 36 hours.
Alyeska typically does one or two line-wide maintenance shutdowns each summer. The pipeline shutdowns are also coordinated with North Slope oil producers' summer work plans.
A similar maintenance shutdown on the pipeline is slated for July 18 to 19.
Reporting by Timothy Gardner; Editing by Walter Bagley