75,960 wells across 2,643 active operators, with 3,627 drilling permits filed in the last 24 months.
Refreshed monthly from CalGEM well-header records. Data current as of 2026-08-16.
Quick answer: The San Joaquin Basin formation in California has 75,960 wells on record across 2,643 active operators, with 3,627 drilling permits filed in the last 24 months (as of 2026-08-16). Its most active operators by well count are Chevron, Aera Energy, California Resources Production, E & B Natural Resources Management and Sentinel Peak Resources Ca. Compiled from California Geologic Energy Management Division (CalGEM) well-header records, refreshed monthly.
The operators with the most well counts targeting the San Joaquin Basin formation in California:
| # | Operator | Wells in San Joaquin Basin |
|---|---|---|
| 1 | Chevron | 34,514 |
| 2 | Aera Energy | 8,885 |
| 3 | California Resources Production | 5,598 |
| 4 | E & B Natural Resources Management | 3,032 |
| 5 | Sentinel Peak Resources Ca | 2,823 |
| 6 | Macpherson Oil Company | 1,236 |
| 7 | Berry Petroleum Company | 1,175 |
| 8 | Shell Oil Company | 537 |
| 9 | Bellaire Oil Company | 535 |
| 10 | Hunter Edison Oil Development LTD | 525 |
The California counties with the most San Joaquin Basin activity:
Kern, Fresno, Tulare, San Benito, Madera
The most recent 100 drilling permits filed for San Joaquin Basin wells in California:
| Permit Date | Well | API | County | Operator | Lateral (ft) |
|---|---|---|---|---|---|
| 2026-08-12 | Elena 14x-32 | 04030703060000 |
Kern | Valley Resources | — |
| 2026-08-12 | Unspecified 62cr1-29 | 04030703070000 |
Kern | Aera Energy | — |
| 2026-08-11 | Unspecified 56ei | 04019225570000 |
Fresno | Aera Energy | — |
| 2026-08-11 | Maxwell 417 | 04030391130000 |
Kern | Aera Energy | — |
| 2026-08-10 | Unspecified 102te-29 | 04030703050000 |
Kern | Aera Energy | — |
| 2026-08-10 | Unspecified 181te-29 | 04030703010000 |
Kern | Aera Energy | — |
| 2026-08-10 | Unspecified 58hr-20 | 04030703000000 |
Kern | Aera Energy | — |
| 2026-08-10 | Unspecified 51k1-29 | 04030703030000 |
Kern | Aera Energy | — |
| 2026-08-10 | Unspecified 178te-28 | 04030703040000 |
Kern | Aera Energy | — |
| 2026-08-10 | Unspecified 83tr1-29 | 04030703020000 |
Kern | Aera Energy | — |
| 2026-08-10 | Unspecified 166te-29 | 04030702990000 |
Kern | Aera Energy | — |
| 2026-08-06 | Maxwell D-708 | 04029737020000 |
Kern | Aera Energy | — |
| 2026-08-06 | Maxwell 264 | 04029777150000 |
Kern | Aera Energy | — |
| 2026-08-04 | Maxwell Z-31 | 04030205640000 |
Kern | Aera Energy | — |
| 2026-08-04 | Kendon 502 | 04030014460000 |
Kern | Aera Energy | — |
| 2026-08-04 | Ruth 78x-13 | 04030702980000 |
Kern | Valley Resources | — |
| 2026-08-03 | Section Seven W-1 | 04019042500000 |
Fresno | Aera Energy | — |
| 2026-07-30 | Mckittrick Unit 1 I-43 | 04030699810000 |
Kern | Sentinel Peak Resources Ca | — |
| 2026-07-29 | Unspecified 167te-29 | 04030702950000 |
Kern | Aera Energy | — |
| 2026-07-29 | Unspecified 62r1ech-29 | 04030702910000 |
Kern | Aera Energy | — |
| 2026-07-29 | Unspecified 48fur-20 | 04030702940000 |
Kern | Aera Energy | — |
| 2026-07-29 | Unspecified 63te-29 | 04030702960000 |
Kern | Aera Energy | — |
| 2026-07-29 | Unspecified 62r1-29 | 04030702930000 |
Kern | Aera Energy | — |
| 2026-07-29 | Unspecified 66te-29 | 04030702900000 |
Kern | Aera Energy | — |
| 2026-07-29 | Unspecified 62te-29 | 04030702970000 |
Kern | Aera Energy | — |
| 2026-07-29 | Unspecified 72d1-29 | 04030702920000 |
Kern | Aera Energy | — |
| 2026-07-29 | Penn-Zier 460 | 04019211410000 |
Fresno | Aera Energy | — |
| 2026-07-28 | Section Seven Ws-2 | 04019212620000 |
Fresno | Aera Energy | — |
| 2026-07-28 | Vedder-Rall 98bh | 04030702890000 |
Kern | California Resources Production | — |
| 2026-07-28 | Canadian 18 | 04019255290000 |
Fresno | Holmes Western Oil | — |
| 2026-07-28 | Section 23 273r | 04030702880000 |
Kern | California Resources Production | — |
| 2026-07-27 | Mcdonald 1-3 | 04030702870000 |
Kern | California Resources Production | — |
| 2026-07-24 | Young Fee 110r | 04030702840000 |
Kern | California Resources Production | — |
| 2026-07-24 | Mcdonald 4-1 | 04030702860000 |
Kern | California Resources Production | — |
| 2026-07-24 | Mcdonald 2-2 | 04030702850000 |
Kern | California Resources Production | — |
| 2026-07-24 | Govt 109 | 04030691280000 |
Kern | Holmes Western Oil | — |
| 2026-07-23 | Section 23 272r | 04030702830000 |
Kern | California Resources Production | — |
| 2026-07-21 | Tejon 539 | 04030382290000 |
Kern | Chevron | — |
| 2026-07-17 | Mckittrick Unit 1-109 | 04030699760000 |
Kern | Sentinel Peak Resources Ca | — |
| 2026-07-15 | Penn-Zier 445 | 04019211380000 |
Fresno | Aera Energy | — |
| 2026-07-15 | Unspecified Section 25 4-3 | 04030702820000 |
Kern | California Resources Production | — |
| 2026-07-10 | Section 23 286r | 04030702810000 |
Kern | California Resources Production | — |
| 2026-07-10 | Unspecified 31w-34s | 04030702770000 |
Kern | California Resources Production | — |
| 2026-07-10 | Opaque Sp1-30 | 04030702760000 |
Kern | Premier Resources | — |
| 2026-07-10 | Opaque Sp3 | 04030702750000 |
Kern | Premier Resources | — |
| 2026-07-10 | Opaque Sp2-30 | 04030702790000 |
Kern | Premier Resources | — |
| 2026-07-10 | Unspecified 64wy-4g | 04030702800000 |
Kern | California Resources Production | — |
| 2026-07-10 | Unspecified 86sy-28s | 04030702780000 |
Kern | California Resources Production | — |
| 2026-07-08 | Aviva 31x-20 | 04030702730000 |
Kern | Valley Resources | — |
| 2026-07-08 | Opaque 1414-30 | 04030702740000 |
Kern | Premier Resources | — |
The San Joaquin Basin is one of California's active oil and gas plays, with 75,960 wells on file across 2,643 distinct operators of record. Operators have filed 3,627 drilling permits targeting the San Joaquin Basin in the last 24 months — a measure of how active the play is right now versus its historical baseline.
For mineral owners with interests in Kern, Fresno, Tulare, San Benito, Madera, knowing whether your tract sits within an active San Joaquin Basin footprint is a foundational valuation question. Active formations with consistent permit flow command premium pricing; legacy formations with steady but declining production are valued differently.
See all California oil & gas formations & plays · Download the California formations dataset (CSV)
75,960 wells target the San Joaquin Basin in California, worked by 2,643 active operators, per CalGEM well-header records (as of 2026-08-16).
By well count, the most active San Joaquin Basin operators in California are Chevron, Aera Energy, California Resources Production, E & B Natural Resources Management and Sentinel Peak Resources Ca. The full ranking is in the table on this page.
Operators filed 3,627 drilling permits targeting the San Joaquin Basin in the last 24 months — a live measure of current activity, per CalGEM records.
Operators filed 3,627 new drilling permits targeting the San Joaquin Basin in California over the last 24 months. New permits and spuds are the clearest signal of active San Joaquin Basin drilling, per CalGEM records (as of 2026-08-16).
San Joaquin Basin activity in California currently spans 75,960 wells on record and 2,643 active operators, led by Chevron, Aera Energy, California Resources Production, E & B Natural Resources Management and Sentinel Peak Resources Ca, with 3,627 drilling permits filed in the last 24 months — refreshed monthly from California Geologic Energy Management Division (CalGEM) well-header records (as of 2026-08-16).
The most active San Joaquin Basin counties in California are Kern, Fresno, Tulare, San Benito, Madera.
Value depends on your net mineral acres or royalty decimal, the operator, the remaining drilling locations, and current oil and gas prices. Buckhead Energy checks your tract against current San Joaquin Basin well and permit data and puts a free, no-obligation written offer in writing — this page is informational only, not a valuation.
Cite this dataset
Permanently archived and citable via a DOI on Zenodo (CERN), under a CC BY 4.0 license. DOI: 10.5281/zenodo.21442884 · View on Zenodo
License & attribution: This data is licensed CC BY 4.0. You are free to share and adapt it, including commercially, provided you credit “Buckhead Energy” and link back to this page or the DOI above.
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Formation: San Joaquin Basin
State: California
Total wells: 75,960
Active operators: 2,643
Permits 24mo: 3,627
Last refresh: 2026-08-16
Free written offers on San Joaquin Basin mineral rights in California.
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