- Alta Resources, LLC
- BHE GT&S
- BKV Operating
- Cabot Oil & Gas Corporation
- Chesapeake Energy Corporation
- Chief Oil & Gas, LLC
- Diversified Gas & Oil Corporation
- DTE Midstream
- Energy Transfer Partners
- EQT Corporation
- Equitrans Midstream Corporation
- Greylock Energy, LLC
- Hilcorp Energy Company
- JKLM Energy, LLC
- MPLX LP
- National Fuel Gas Midstream Company, LLC
- NRG Energy
- Olympus Energy LLC
- PennEnergy Resources, LLC
- Pennsylvania General Energy Company, LLC
- Peoples Natural Gas
- Range Resources Corporation
- REPSOL
- Seneca Resources Company, LLC
- Southwestern Energy Company
- Stonehenge Energy Resources II, LLC
- UGI Energy Services
- Williams
- XTO Energy