Prices have recovered slightly from last Thursday's low of $57.22, driven by expectations the Organization of Petroleum Exporting Countries will agree to an output cut to prevent prices from sliding further.
U.S. oil has fallen from record mid-July highs above $78 a barrel, weighed down by healthy global inventory levels.
"The OPEC cut and winter fears are limiting the downside but at the same time, the upside is limited by the high crude inventories in the United States," said Tony Nunan, a risk manager with Japan's Mitsubishi Corp.
