| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Santo Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 2 | Secan Oil Co Inc | Oil & Gas Operator | May 1987 | |
| 3 | Serio Energy Corporation | Oil & Gas Operator | Jul 2000 | |
| 4 | Serio Operating Co. | Oil & Gas Operator | Mar 2007 | |
| 5 | Serio-Punches Oil Co | Oil Operator | Jan 2008 | |
| 6 | Sidney E. Pinkston, Jr, Trustee | Oil & Gas Operator | Apr 1980 | |
| 7 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2026 |
| 8 | Smith, Clyde H. Oper. Co., Inc. | Oil & Gas Operator | Jun 1994 | |
| 9 | Sooner Corp | Oil & Gas Operator | Oct 1990 | |
| 10 | Southern Hydrocarbons Inc | Oil & Gas Operator | Jul 1989 | |
| 11 | Southwest Mississippi Oil & Gas LLC. | Oil Operator | Feb 2026 | |
| 12 | Standard Operating Inc | Oil Operator | Jun 1986 | |
| 13 | Streetman Inc | Oil Operator | Oct 1987 | |
| 14 | Sun Exploration And Production Co | Oil & Gas Operator | Jan 1990 | |
| 15 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Apr 2026 |
| 16 | Sunland Production Company, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2026 |