Oil prices have been volatile again, hit by continuing oversupply, the strong dollar and weak global demand.
Some members of the Opec group of oil producers have called for an emergency meeting to discuss reducing output.
Opec president Emmanuel Ibe Kachikwu said an extraordinary meeting could be held in early March.
On Tuesday, Brent crude fell as low as $30.43 per barrel before recovering to trade 0.5% higher at $31.75 a barrel.
Meanwhile the US benchmark, West Texas Intermediate, slipped to $30.41 before regaining some ground to $31.06 a barrel.
Oil prices have fallen about 15% since the start of the year to near-12 year lows.
North Sea Brent Crude has fallen 70% since September 2014, when it it was last at $100 per barrel.