Energy stocks were lower Thursday afternoon, with the NYSE Energy Sector Index and the Energy Select Sector SPDR Fund (XLE) each shedding 0.4%.

The Philadelphia Oil Service Sector index was falling 1.3%, and the Dow Jones US Utilities index declined 0.4%.

Front-month West Texas Intermediate crude oil rose 2% to $63.90 a barrel, and the global benchmark Brent crude contract advanced 1.7% to $66.75 a barrel. Henry Hub natural gas futures were 0.1% higher at $2.83 per 1 million BTU.

US natural gas stocks rose by 56 billion cubic feet in the week ended Aug. 8, larger than the 54 billion gain expected in a survey compiled by Bloomberg and well above an increase of 7 billion cubic feet in the previous week.

In corporate news, Phillips 66 (PSX) has cut gasoline output at its Bayway refinery in New Jersey following a fire close to the plant's gasoline producing unit, Reuters reported. Phillips 66 shares declined 0.3%.

Epsilon Energy (EPSN) shares tumbled nearly 16% after the company late Wednesday reported Q2 earnings and said it agreed to buy 40,500 net oil and gas acres in the Powder River Basin in Wyoming from two entities majority owned by Yorktown Energy Partners funds for $86.3 million in stock and debt.

Brazilian sugar and ethanol producer Raizen, backed by Cosan (CSAN) and Shell (SHEL), is pursuing new funding as rising debt and weak investment returns drove its shares down 15% to a record low of 1.02 Brazilian reais ($0.19) in Sao Paulo, Bloomberg reported. Shell shares were down 0.5%.