Oil futures tilted higher in Asian trade with US crude off January 26 lows, while Brent climbed from February 18 lows, as the dollar index scaled July 14 highs.
It comes ahead of a spate of US data later today, and amid ongoing negotiations between the US and Iran on the nuclear deal, which might open up Iranian exports to the world.
As of 05:39 GMT, US crude futures due in September rose 0.43% to $90.94 a barrel, while Brent October futures rose 0.50% to $97.06 a barrel, as the dollar index rose 0.08% to 109.09.
Zephyr Energy plc (LON:ZPHR) is an investment platform formed to aggregate responsibly-developed, economically-attractive oil and gas interests in the Rocky Mountain region of the United States.