US commercial crude stocks rose 1.45 million barrels to 383.91 million barrels in the reporting week that ended June 6, American Petroleum Institute data showed Tuesday.
Analysts surveyed Monday had been expecting a 1.2 million-barrel draw.
The unexpected build in stocks was likely a product of a 434,000 b/d decline in crude runs, which fell to 15.45 million b/d, according to API.
This helped to cut refinery utilization rates by 2.1 percentage points to 87.8% of capacity. Analysts had been expecting a 0.5 percentage point decline.
Runs on the US Gulf Coast fell 487,000 b/d to 7.62 million b/d, pushing utilization rates in that region 5.1 percentage points lower to 84.1% of capacity, according to the trade group.
As a result, USGC crude stocks rose 1.95 million barrels to 204.65 million barrels. A 65,000 b/d fall in USGC imports to 3.08 million b/d also helped to limit the build.
Crude stocks at Cushing, Oklahoma -- delivery point for the NYMEX crude futures contract -- fell 213,000 barrels to 21.21 million barrels, API data showed.
US gasoline stocks, meanwhile, fell 441,000 barrels to 213.33 million barrels last week, largely in line with analysts' expectations.
Stocks on the USGC were largely flat at 72.97 million barrels despite a 223,000 b/d drop in production to 2.05 million b/d.
US Atlantic Coast gasoline stocks fell 1.65 million barrels to 59.9 million barrels amid a 57,000 b/d decline in production, which fell to 3.09 million b/d.
US distillate stocks were largely flat, dipping 298,000 barrels to 116.23 million barrels last week. Analysts had been looking for a 750,000-barrel build.
USGC production fell 171,000 b/d to 2.54 million b/d last week. Of this, USGC ULSD production dropped 143,000 b/d to 2.28 million b/d.
This helped USGC ULSD stocks to fall 1.02 million barrels to 30.78 million barrels.
