West Texas Intermediate oil futures bounced off six-and-half year lows Thursday, getting a lift from weakness in the U.S. dollar as the September contracts expired. But the move represented a modest tick higher for the commodity which has been pressured by a surprise weekly increase in crude supplies and concerns about the Chinese economy.

Crude futures for delivery in September gained 34 cents, or 0.8%, to settle at $41.14 a barrel, after settling Wednesday at the lowest since March 2, 2009. The September futures contracts expired at the close. October crude which became the front-month contract, settled at $41.32, up a nickel.

The expiration of the September WTI contract “amplified volatile conditions in an already wild energy market,” said Tyler Richey, co-editor of The 7:00’s Report. “The primary supporting factor for oil prices today, as well as the general commodity space, was the continued weakness in the dollar which is now down over 1% from the best levels of the week.” Meanwhile, October Brent crude shed 54 cents, or 1.2%, to $46.62 a barrel on the ICE Futures exchange, extending its losses to a second straight session. It marked its fifth loss in six sessions.

U.S. oil prices fell sharply Wednesday after the U.S. Energy Information Administration reported a surprise 2.6 million-barrel increase in last week’s U.S. commercial crude stocks on the back of higher imports on the Gulf Coast. “A drop in refinery utilization, combined with imports popping above 8 million barrels per day for the first time since April, flip-flopped the expectation of a 2 million barrel draw into the reality of a solid build,” said Matt Smith, director of commodity research at ClipperData. Meanwhile, Citi Futures noted that the latest figures from the Joint Organizations Data Initiative show Saudi Arabian oil exports rising by 430,000 barrels a day to 7.37 million barrels a day — a reminder of the global oil surplus.

Investors also remain jittery over the Chinese equity market, fluctuations in the yuan and the outlook for the country’s economic growth in general.