The price of oil reached its highest point in eight weeks trading near $79 a barrel.
For August delivery, US crude rose 52¢ before falling 9¢ to stand at $78.77 by 06.48 GMT, while London Brent crude dropped 12¢ to $78 a barrel, according to Reuters.
Mexico has slowed oil exports because of tropical storm Alex, which has also forced BP and Shell to evacuate platforms and curb output.
OPEC said it is comfortable with the current oil prices and does not expect production levels to change until October.
