West Texas Intermediate sweet, light crude oil started the week under $103. On Friday, WTI crude gained 29 cents to reach $103.60 per barrel.
Traders were reacting to news that the Republican Party's leadership in Washington appears unwilling to push the U.S. government into default in mid-October by failing to raise the federal government's credit limit.
TransCanada said this week it was nearing completion of one leg of the Keystone XL oil pipeline project.
Analysts said the pipeline would even out supplies, moderating occasions when inventories are too high.
On the New York Mercantile Exchange, reformulated blendstock gasoline prices lost 3.52 cents to $2.6044 per gallon. Home heating oil shed 0.53 cents to $2.998 per gallon. Natural gas added 2 cents to reach $3.51 per million British thermal units.
At the pump, the national average price of unleaded gasoline fell to $3.366 per gallon from Thursday's $3.376, AAA's Daily Fuel Gauge Report said.