NEW YORK, May 15 (Reuters) - U.S. crude stocks surged again last week, with the increase nearly four times more than what analysts had expected, due in part to stocks at the key Cushing oil hub increasing by nearly 3 million barrels, data from the American Petroleum Institute (API) showed on Tuesday.
U.S. crude oil inventories rose 6.57 million barrels in the week to May 11, outpacing analysts’ expectations of a rise of 1.7 million barrels, the API said. If confirmed by government data on Wednesday, it will be the eighth successive build.
Crude stocks at Cushing, Oklahoma, the delivery point for West Texas Intermediate crude, rose by 2.8 million barrels. If confirmed on Wednesday, Cushing stocks will have reached a record high just days before the Seaway oil pipeline is due to begin pumping surplus crude from there to the Gulf Coast.
U.S. crude oil prices slightly extended losses by several pennies to hit a year low of $93.05 a barrel after the API released its numbers. The Brent/WTI spread widened by nearly $2 a barrel earlier on Tuesday, before the data showed record-high inventories that could further weigh on U.S. prices.
The latest surprising jump in crude stocks came as refinery operations unexpectedly slowed last week, contrary to forecasts that operators would rev up runs ahead of the summer driving season. The decline occurred despite a pick-up in imports, which rose by 151,000 barrels per day (bpd) to 8.8 million bpd.
The draw in stocks was largely split between Padd 2, which is the Midwest including Cushing, and Padd 3, which includes the Gulf Coast.
Gasoline inventories fell by 2.6 million barrels last week, far more than the 500,000-barrel drop analysts had projected. The decline was split between the Midwest and West Coast, both of which fell by about 1.5 million barrels.
Domestic distillate stockpiles also fell, by 1.6 million barrels, compared with forecasts for a 600,000-barrel draw.
U.S. refinery rates slipped 0.2 percentage point to 84.8 percent of capacity, opposite of analysts’ expectations for a 0.4-percentage-point increase.
Traders will now await data from the U.S. Energy Information Administration for confirmation of the API report. Last week, EIA data showed Cushing’s crude inventories at a record high, while overall crude stocks reached the highest level since 1990.