US crude oil stockpiles fell by nearly 10 million barrels last week, far more than expected, as refineries processed the most crude oil since January, the Energy Information Administration said on Wednesday.
Crude inventories fell by 9.5 million barrels in the week to July 5, compared with analysts' expectations for a decrease of 3.1 million barrels.
Stocks have now fallen for four consecutive weeks, according to the EIA, and this week's official data follows similar industry estimates from the American Petroleum Institute on Tuesday, which showed a large drop in stocks of 8.1 million barrels.
"The inventory draw was much stronger than expected and also exceeded the already huge draw reported by the API yesterday. This should push oil prices even higher," said Carsten Fritsch, oil analyst at Commerzbank. "The US oil market is clearly tightening."
Oil prices extended gains after the data. By 10:48 a.m. EDT (1448 GMT), US crude futures were up 3% at $59.59 a barrel, while Brent gained 3% as well to $66.06 a barrel.
The market was already higher before the data, partly due to numerous oil majors operating in the Gulf of Mexico shutting drilling facilities and evacuating staff ahead of a tropical cyclone forming in the Gulf, which is bringing high winds and storms.
Refinery crude runs rose by 148,000 barrels per day to hit 17.4 million bpd, the most since early January, responding to higher summer demand.
Refinery utilization rates rose by 0.5 percentage points to 94.7% of overall capacity, also their highest since January. That is even though refinery operations fell to 69.5% of capacity on the East Coast in the wake of the shutdown of the Philadelphia Energy Solutions complex, the largest in the region.
Gulf Coast operating rates were at nearly 98% of capacity - their most since December.
Gasoline stocks fell by 1.5 million barrels, near analysts' expectations in a Reuters poll for a 1.3 million-barrel drop.
Distillate stockpiles, which include diesel and heating oil, rose by 3.7 million barrels, versus expectations for a 739,000-barrel increase, the data showed.
Net US crude imports fell last week by 341,000 bpd, while crude production edged up 100,000 bpd to 12.3 million bpd.
Crude stocks at the Cushing, Oklahoma, delivery hub for crude futures fell by 310,000 barrels, EIA said.