| Code | Description |
| CBM | Coalbed Methane Gas Well |
| CLASS I EPA | Class I Disposal Well (EPA Jurisdiction) |
| CLASS II EPA | Class II Disposal Well (EPA Jurisdiction) |
| CO2 | Carbon Dioxide Gas Well |
| DA | Dry & Abandoned Well |
| DM | Domestic Well |
| DSPW | Class II Disposal Well |
| ERIW | Enhanced Recovery Injection Well |
| GEO-INJ | Geothermal Injection Well |
| GEO-PRD | Geothermal Production Well |
| GEO-SCI | Geothermal Science Well |
| GS-MNTR | Geologic Storage Monitoring Well |
| GS-SCI | Geologic Storage Science Well |
| GS-VI | Class VI |
| GW | Methane Gas Well |
| HE | Helium Gas Well |
| LO | Permitted Well Location |
| OBW | Observation Well |
| OTH | Other |
| OW | Oil Well |
| STOW | Gas Storage Well |
| STRT | Stratigraphic Well |