wellcensus.com
The census of U.S. oil & gas wells
4,166,704 wellbores from 23 state regulator registries plus the federal orphaned-well inventory — the largest free well registry in America. API number, operator, status, dates, depth and location on one public atlas. The full US universe is ~3 million drilled wells; per-state coverage is documented honestly in the methodology. Click a state to drill in, or open the live well map.
Catalogued wells
4,166,704
28 states with data
Active wells
1,202,206
Producing or permitted-active
Documented orphans
164,816
No solvent operator of record
Operators
101,832
Canonical, cross-state resolved
Dataset updated . Derived from state oil & gas regulator registries + the USGS documented-orphaned-wells inventory.
Open the live well map →164,816 documented orphan wells
Orphaned wells have no solvent operator left to plug them — and $4.7 billion in federal plugging funds is flowing to the states to deal with them. WellCensus maps every documented orphan in the USGS inventory plus state-flagged orphans, by state and county.
Explore orphan wells →Largest well operators
Full ranking →| Operator | Wells | Active | Plugged | States |
|---|---|---|---|---|
| Historic Owner | 118,046 | 18,978 | 67,274 | OH |
| Chevron USA | 65,303 | 13,921 | 43,648 | AL AR CA CO KS LA MI ND NM OH OK PA UT WV WY |
| Aera Energy | 57,745 | 13,425 | 35,647 | CA |
| Inactive Operator | 45,271 | 0 | 39,755 | LA |
| Diversified Production | 31,363 | 28,431 | 688 | AL KY LA OH OK WV |
| Diversified Prod | 21,609 | 17,980 | 406 | PA |
| Hilcorp Energy | 19,950 | 15,820 | 2,086 | AL CO LA MS NM OH PA WY |
| Eog Resources | 16,762 | 2,897 | 4,127 | AR CA CO KS LA MI MS MT ND NM NY OH OK PA UT WV WY |
| Pa Dep Ofc Oil & Gas Mgmt | 12,967 | 0 | 3,391 | PA |
| Scout Energy Management | 12,456 | 9,882 | 1,040 | CO KS MT ND NM OK UT |
Wells by state
23 states carry state-registry records (Texas and Nebraska as location indexes while their full-attribute files land); the remaining states shown carry the federal orphaned-well overlay only. Per-state coverage, sources and caveats: methodology.
Data access
Request full data access
Weekly state files, the REST API and an MCP server for the multi-state well registry — API numbers, status, operators, dates and orphan-well flags. Tell us where to reach you.
We'll only use your email for this. No spam.