Benchmark crude was up 15 cents to $101.46 per barrel at midday Singapore time in electronic trading on the New York Mercantile Exchange. The contract rose 52 cents to settle at $102.32 per barrel in New York on Thursday.
Brent crude was up 29 cents at $120.40 per barrel in London.
Crude has jumped from $96 earlier this month as a surge in stock markets suggests investor confidence in the U.S. economic outlook is improving. The U.S. Labor Department said weekly applications for unemployment benefits dropped for the fourth time in five weeks to the lowest point since March 2008.
The Dow Jones industrial average rose 1 percent Thursday to its highest level in almost four years while Asian stocks jumped on Friday.
Rising fears that a military conflict will erupt over Iran's nuclear program and block oil supplies from reaching markets has also helped push crude prices higher.
The U.S. and Europe are tightening economic sanctions against Iran over what the West believes is Iran's attempt to build a nuclear bomb. World leaders fear Israel may be planning a strike against Iran.
In response, Iran, which is the world's third largest exporter, has threatened to withhold its own oil deliveries and to block the Strait of Hormuz, through which one-fifth of the world's oil flows.
"Given the headlines regarding Iran, the market appears to be entering panic mode," energy traders and consultant The Schork Group said in a report. "In this current sky-is-falling market, facts like weak demand relative to supply are overshadowed by fear and greed. Bottom line, this oil market is afraid, very afraid."
Some analysts are starting to worry that rising fuel costs will undermine consumer spending and stymie economic growth. At about $3.50 a gallon, the average U.S. price for gasoline is 38 percent higher than a year ago and likely to raise into the summer, said Carl Larry of energy consultant Oil Outlooks and Opinions.
"We all have to wonder now if that's going to have a deteriorating effect on the current growth of America," Larry said. "The question now is will America be ready for this shock?"
A slowdown in consumer spending in developed countries would likely hurt demand for Asian exports and the region's economic growth. Asia currently accounts for most of the world's crude demand growth.
"The cost of crude acts like a tax on economic activity," HSBC said in a report. "As crude costs push higher, demand for the region's exports quickly softens. For Asia, the current risk from rising oil prices isn't inflation, it's growth."
In other energy trading, heating oil was down 1.2 cents at $3.18 per gallon and gasoline futures slid 1.3 cents to $3.16 per gallon. Natural gas rose 0.7 cent to $2.43 per 1,000 cubic feet.