- American Natural Energy Corp
- Apache Corp
- Bankoff Oil Co
- Beta Oil & Gas Inc
- Breeze Investments LLC
- C E Harmon Oil Inc
- Calumet Petroleum LTD
- Dmf Inc
- Empress Gas Corp LTD
- Kahan & Assoc Inc
- Kaiser Francis Anadarko LLC
- Mid Con Energy Corp
- Oakland Petroleum Operating Co
- PITCO
- RDT Properties
- Rhoades Oil Co
- Robinowitz Oil Co
- St Mary Land & Exploration Co
- Thomas Exploration Co
- Warren American Oil Co
- Western Resource Development