Oil futures were little changed Wednesday after the Energy Information Administration released new petroleum inventory figures that showed a surprising decrease in crude stores from the previous week.

August light sweet crude was down 25 cents at $72.56 a barrel on the New York Mercantile Exchange. Reformulated gasoline fell 6 cents to $2.31 a gallon, and heating oil edged a penny lower to $2.11 a gallon.

Natural gas was down 10 cents at $6.60 per million British thermal units.

The EIA's inventory report for the week ended July 6 showed that crude stores fell by 1.5 million barrels. Analysts had been expecting a 50,000-barrel decline. Gasoline inventories grew by 1.1 million barrels, whereas analysts were expecting an 825,000-barrel injection.

Distillate stocks grew by 760,000 barrels, which was slightly lower than what analysts had predicted. Refinery utilization increased slightly to 90.2% from 90.0%.

According to Alan Mandel, analyst at Alan M. Trading, the Commitment of Traders Report published by the Commodity Futures Trading Commission currently shows a record open interest in oil futures.

"This usually means that most of the optimistic buyers are already in the market and that crude should be feeling some downside pressure," he said.

Meanwhile, oil and gas stocks were mixed. The CBOE Oil Index rose 0.5% to 795.15.

RBC Capital Markets downgraded a large swath of oil-service companies to sector perform from outperform, saying in a note that high natural gas inventories in the U.S. will likely weigh on some domestic energy companies through the end of the year.

The downgraded stocks were all weaker. Halliburton ( HAL - Get Report) was down 1.4%, BJ Services ( BJS) lost 0.4%, Patterson-UTI ( PTEN - Get Report) fell 1.7%, and Nabors ( NBR - Get Report) was weaker by 1%.

Grey Wolf ( GW) surrendered 2%, and Basic Energy Services ( BAS) was down 1.6%.

Merrill Lynch also cut a group of oil service stocks, taking Noble ( NE - Get Report), Global Santa Fe ( GSF), Baker Hughes ( BHI) and Smith International ( SII) to neutral from buy. All fell at least 1%.

The firm took Ensco ( ESV) to sell from neutral, causing it to fall 2%.