West Texas intermediate crude, which had begun the week near $104 per barrel, was off $1.08 late in the day to $101.93.
Reformulated blendstock gasoline prices were off 3.12 cents to $2.667 per gallon. Home heating oil lost 3.82 cents to $3.0318 per gallon. Natural gas added 0.58 cents to reach $3.781 per million British thermal units.
At the pump, the national average price of unleaded gasoline dropped to $3.345 per gallon from Thursday's $3.351, AAA's Daily Fuel Gauge Report said.