| 1 | Carbon Oil Inc | Vidor, TX 77670 | Oil & Gas Operator | Oct 2025 |
| 2 | Cashco Oil Company | Houston, TX 77024 | Oil & Gas Operator | Aug 2003 |
| 3 | Caskids Operating Company | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 4 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jun 2025 |
| 5 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 6 | Christensen & Matthews | Houston, TX 77040 | Oil & Gas Operator | Oct 2025 |
| 7 | Cico Oil & Gas Company | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 8 | Cimarron Engineering, LLC | Kingsville, TX 78364 | Oil & Gas Operator | Oct 2025 |
| 9 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 10 | Coastline Exploration, Inc. | Stafford, TX 77477 | Oil & Gas Operator | Oct 2025 |
| 11 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Aug 2025 |
| 12 | Cokinos, Inc. | Beaumont, TX 77701 | Oil & Gas Operator | Aug 2003 |
| 13 | Conoco Inc. | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 14 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 15 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Oct 2025 |
| 16 | Contour Expl And Prod, LLC | Dallas, TX 75204 | Oil & Gas Operator | Oct 2025 |
| 17 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 18 | Copestone Operating, LLC | Houston, TX 77019 | Oil & Gas Operator | Oct 2025 |
| 19 | Core E & P Corp. | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 20 | Costa Energy, LLC | Irving, TX 75063 | Oil & Gas Operator | Oct 2025 |
| 21 | Cummins & Walker Oil Co., Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2021 |