World oil prices rose after data showed crude stockpiles fell by a sharper-than-expected amount in the United States.
US crude for delivery in August climbed $0.75 to $77.90 a barrel.
Brent North Sea crude for August gained 79 cents to 77.44 dollars.
The US Department of Energy (DoE) said US crude stockpiles slumped 5.1 million barrels last week. Analyst forecasts had been for a drop of only 1.2 million barrels.
Oil prices extended gains after soaring yesterday, when the dollar weakened and the International Energy Agency (IEA) forecast that demand was projected to increase slightly this year.
Meanwhile, strong US company results have sparked hope of rising energy demand in the world's biggest economy.
