Fears that U.S. politicians will fail to agree on a new debt ceiling and perhaps trigger a default led to a drop in crude oil prices on Friday.
US benchmark, West Texas Intermediate crude for July dropped 25 cents or 0.3% to close at $71.69 a barrel on the New York Mercantile Exchange.
Brent crude, the global benchmark, slipped 28 cents or 0.8% and finished at $75.58 a barrel on ICE Futures Europe.
June natural gas was unchanged at $2.59 per 1,000 cubic feet.
Oklahoma energy stocks were mixed as some recorded gains while others lost ground on Friday. Empire Petroleum gained more than 3% for the day while other stocks recorded minimal losses.

APA Corp. (Apache) (APA) up 0.70 at 33.40 – change 2.14%
Cheniere (LNG) down 0.75 at 141.18 – change 0.53%
Chevron (CVX) up 1.22 at 155.22 – change 0.79%
ConocoPhillips (COP) up 1.86 at 102.60 – change 1.84%
Diamondback Energy (FANG) up 1.48 at 130.22 – change 1.14%
Energy Transfer LP (ET) up 0.04 at 12.76 – change 0.31%
Enterprise Products Partners (EPD) up 0.12 at 26.20 – change 0.46%
EOG Resources (EOG) up 2.57 at 114.59 – change 2.29%
ExxonMobil (XOM) up 0.49 at 106.26 – change 0.46%
Kinder Morgan (KMI) unchanged at 16.52 – change 0.00%
Marathon Oil Corp. (MRO) up 0.02 at 23.07 – change 0.08%
NOV Inc. (NOV) down 0.08 at 15.11 – change 0.53%
Occidental Petroleum (OXY) up 0.88 at 59.13 – change 1.51%
Phillips 66 (PSX) down 0.29 at 94.94 – change 0.31%
Pioneer Natural Resources (PXD) up 4.97 at 208.94 – change 2.03%
Tellurian Inc. (TELL) up 0.01 at 1.33 – change 0.75%
Valero (VLO) down 0.29 at 111.27 – change 0.26%
CLOSING TOP UTILITY STOCKS
American Electric Power (AEP) down 0.08 at 86.56 – change 0.10%
CenterPoint (CNP) up 0.15 at 28.59 – change 0.52%
Entergy (ETR) down 0.95 at 100.55 – change 0.94%