Imported from jpfielding/claude.pnge (plugins/pnge-state-regulatory/skills/calgem/SKILL.md). Install upstream with npx skills add jpfielding/claude.pnge --skill calgem. Copyright stays with the author.

California CalGEM (DOGGR) Data Skill

Queries oil, gas, and geothermal well data from the California Geologic Energy Management Division (CalGEM). CalGEM (renamed from DOGGR — Division of Oil, Gas and Geothermal Resources — on January 1, 2020) is the state agency within the California Department of Conservation that regulates drilling, operation, and plugging of wells.

California matters for Li/Mg research for two distinct reasons:

1. Salton Sea KGRA (Imperial County) — the single largest known geothermal brine lithium resource in the U.S. Active development projects: Hell's Kitchen (Controlled Thermal Resources / CTR), EnergySource Minerals (ATLiS), and BHE Renewables (Berkshire Hathaway Energy) at the existing geothermal power plants.
2. Kern County (San Joaquin Basin) — the largest oilfield produced-water volume in the United States, with some of the strictest disclosure rules (SB 1281, 2014) and the most extensive Class II injection well network in the western U.S.

API Key Handling

No API key required. All CalGEM ArcGIS REST services and public portal data are freely accessible without authentication.

Data Access Architecture

CalGEM exposes data through four channels:

1. ArcGIS REST services (preferred for programmatic access) — WellSTAR map services return JSON for well locations, attributes, and status.
2. Well Finder web app — interactive map UI backed by the same REST services.
3. Bulk data files — monthly production/injection reports (PDF/XLS per operator) and statewide roll-up files published on the CalGEM website.
4. File Request system — PDF well records, logs, and histories by API number.

Channel 1: ArcGIS REST Services (Preferred)

Root: https://gis.conservation.ca.gov/server/rest/services/

Folders: CalGEM, WellSTAR, plus supporting layers under Base, CGS, DLRP, DMR, DO, MOL.

All services support standard ArcGIS REST query operations. maxRecordCount is 5000 per request; paginate with resultOffset and resultRecordCount.

Channel 2: Well Finder (Interactive)

https://maps.conservation.ca.gov/doggr/wellfinder/ — ArcGIS Web AppBuilder frontend over the WellSTAR/Wells service. Useful for human navigation; not an API but pages will link back to the REST service for bulk downloads.

Channel 3: Bulk Data Files

CalGEM publishes monthly production and injection reports as PDF/XLS files by operator and by field, plus annual statewide roll-ups. The index URL changes across SharePoint redesigns. Current path (verify if 404):

https://www.conservation.ca.gov/calgem/pubs_stats (occasionally redirects — the portal has been reorganized multiple times since the DOGGR→CalGEM rename).

If the pubs_stats path 404s, search the CalGEM site for "Annual Report of the State Oil and Gas Supervisor" and "monthly production injection".

Historical annual "Publication PR" (PR06) statewide data are archived as PDF volumes going back to 1915.

Channel 4: File Request System

https://filerequest.conservation.ca.gov/ — request well-history PDFs, logs, cores, cuttings descriptions, and drilling records by API number. Free; may require account registration for bulk requests.

Query Patterns

Well Search by County, Operator, or Field

# All Water Disposal wells in Kern County (sample 10)
curl -s "https://gis.conservation.ca.gov/server/rest/services/WellSTAR/Wells/MapServer/0/query" \
  --data-urlencode "where=CountyName='Kern' AND WellType='Water Disposal'" \
  --data-urlencode "outFields=API,LeaseName,WellNumber,WellStatus,WellType,OperatorName,FieldName,District,CountyName" \
  --data-urlencode "returnGeometry=false" \
  --data-urlencode "resultRecordCount=10" \
  --data-urlencode "f=json"

Geothermal Wells in Imperial County (Salton Sea KGRA)

# Count geothermal wells in Imperial County
curl -s "https://gis.conservation.ca.gov/server/rest/services/WellSTAR/Wells/MapServer/1/query" \
  --data-urlencode "where=CountyName='Imperial'" \
  --data-urlencode "returnCountOnly=true" \
  --data-urlencode "f=json"
# Returns: {"count":1589}  (as of 2026-04)

# Active geothermal wells — pull operator + field + status
curl -s "https://gis.conservation.ca.gov/server/rest/services/WellSTAR/Wells/MapServer/1/query" \
  --data-urlencode "where=CountyName='Imperial' AND WellStatus='Active'" \
  --data-urlencode "outFields=APINumber,LeaseName,WellNumber,WellStatus,WellType,OperatorName,FieldName,AreaName,Lat83,Long83" \
  --data-urlencode "returnGeometry=false" \
  --data-urlencode "resultRecordCount=50" \
  --data-urlencode "f=json"

Spatial Query — Bounding Box around Salton Sea

# Envelope covers the Salton Sea KGRA (approx)
curl -s "https://gis.conservation.ca.gov/server/rest/services/WellSTAR/Wells/MapServer/1/query" \
  --data-urlencode "geometry=-115.9,33.05,-115.4,33.55" \
  --data-urlencode "geometryType=esriGeometryEnvelope" \
  --data-urlencode "inSR=4326" \
  --data-urlencode "spatialRel=esriSpatialRelIntersects" \
  --data-urlencode "outFields=APINumber,OperatorName,FieldName,WellStatus" \
  --data-urlencode "returnGeometry=false" \
  --data-urlencode "f=json"

Lookup a Well by API Number

California API numbers are 8 digits (county prefix + sequence). CalGEM strips the 04- (state) and -0000 (completion sidetrack) portions seen in federal API.

curl -s "https://gis.conservation.ca.gov/server/rest/services/WellSTAR/Wells/MapServer/0/query" \
  --data-urlencode "where=API='02920123'" \
  --data-urlencode "outFields=*" \
  --data-urlencode "f=json"

Aquifer Exemption Overlap (Class II Injection Context)

# All aquifer exemptions in Kern County
curl -s "https://gis.conservation.ca.gov/server/rest/services/CalGEM/Primacy_Aquifer_Exemptions/MapServer/0/query" \
  --data-urlencode "where=1=1" \
  --data-urlencode "outFields=*" \
  --data-urlencode "returnGeometry=false" \
  --data-urlencode "resultRecordCount=10" \
  --data-urlencode "f=json"

Layer 0 (Oil and Gas Wells) — Key Fields

Layer 1 (Geothermal Wells) — Key Fields

Extra fields beyond Layer 0: GeoDistrict (geothermal-specific district numbering), WellStatusDescription, ABDdate (abandonment date), CompDate (completion), Lat83/Long83 (NAD83 coordinates), DatumCode.

Workflow

Step 1 — Resolve Intent

Step 2 — Source Pick (Well Finder vs CalWIMS vs bulk)

• Well Finder (maps.conservation.ca.gov/doggr/wellfinder/) — for humans; use only as a visual sanity check.
• WellSTAR REST — the machine-readable source of truth for well locations and attributes. Use for all programmatic queries.
• CalWIMS (wims.conservation.ca.gov) — legacy Well Information Management System. The domain redirects as of 2026-04 and its functions have largely migrated into WellSTAR. If the user names CalWIMS, explain the migration and fall back to WellSTAR.
• Bulk monthly reports — for production/injection volumes per operator per field. Must be downloaded from the CalGEM site; not in the REST API.

Step 3 — Fetch Data

Use curl with --data-urlencode for REST queries. Respect maxRecordCount (5000). Paginate with resultOffset for large sets. Use returnCountOnly=true first for large filters to estimate pagination.

Step 4 — Parse Response

JSON. Each feature has attributes (the fields) and optionally geometry. For tabular research use returnGeometry=false.

Step 5 — Produce Output

Format: Raw Data Table + Narrative

## Geothermal Wells — Imperial County (Salton Sea KGRA)

| API       | Operator                          | Field          | Status  | Type        |
|-----------|-----------------------------------|----------------|---------|-------------|
| 02500123  | BHE Renewables                    | Salton Sea     | Active  | Geothermal  |
| 02500456  | EnergySource Minerals (ATLiS)     | Salton Sea     | Active  | Geothermal  |
| 02500789  | Controlled Thermal Resources      | Hell's Kitchen | Drilling| Geothermal  |
...

Summary: 1,589 geothermal wells recorded in Imperial County across the Salton
Sea KGRA. Three operators dominate the active lithium-relevant development:
BHE Renewables (legacy geothermal power), EnergySource Minerals (ATLiS DLE
pilot), and Controlled Thermal Resources (Hell's Kitchen integrated geothermal
+ Li project). Salton Sea brines carry ~200-400 mg/L Li at ~250,000-300,000
mg/L TDS — roughly the same Li range as the Smackover Formation (Arkansas)
but with the critical advantage of arriving at surface at ~300 degC, already
hot enough for direct lithium extraction (DLE) without supplementary heating.

CalGEM District Reference

Districts Critical for Li/Mg Research

• District 4 (Bakersfield / Kern County): 70,000+ producing wells, >75% of California's oil output, ~85% of the state's produced water. Monterey Formation and overlying diatomite reservoirs yield 8-10 barrels of water per barrel of oil in mature heavy-oil fields. Li concentrations in California oilfield waters are much lower than Smackover (typically <10-30 mg/L), but volumes are enormous. SB 1281 (2014) forces monthly disclosure of injected and produced water by source and destination — one of the richest water-accounting datasets in the U.S.
• District 6 (Imperial / Salton Sea): 11 operating geothermal power plants on the southeastern shore of the Salton Sea. The hypersaline brine (~25-28 wt% TDS, ~300 degC) carries ~200-400 mg/L Li — economically recoverable by DLE. Hell's Kitchen, ATLiS, and BHE's integrated lithium projects target this resource. See references/salton_sea_li.md.

Li/Mg Quick-Reference: California vs Other Basins

The key California contrast: Salton Sea wins on grade and heat; Kern loses on grade but wins on volume and regulatory data quality (SB 1281).

Error Handling

Caveats and Data Limitations

1. Portal redesigns: CalGEM's website (pubs_stats, WellReports.aspx, calwims subdomain) has been reorganized multiple times since the 2020 DOGGR → CalGEM rename. Many older links 404. The ArcGIS REST services at gis.conservation.ca.gov are stable; prefer them.
2. SB 1281 data quality: SB 1281 (2014) requires monthly reporting of water injected and produced volumes by source and destination for oilfield operators. Reporting is robust for volumes but has known gaps in water chemistry — operators are not compelled to report TDS or full ion suites unless specifically required by a RWQCB order. See CCST 2020 report for a critique of SB 1281 data completeness.
3. Geothermal vs oilfield distinction: CalGEM regulates both, but they are governed by different sections of the Public Resources Code. Layer 0 (Well) covers oil & gas; Layer 1 (Geothermal Well) covers geothermal. These share WellStatus and WellType vocabularies but not field names or operators. Do not conflate them in analysis.
4. API number format: California uses 8-digit API, distinct from the 14-digit federal API. The county code (first 3 digits) maps to California county FIPS. Cross-basin joins with USGS produced-waters DB require care.
5. Confidential wells: isConfidential='Y' / Confidential='Y' means the well is within the 24-month confidentiality window after spud — some attributes may be redacted.
6. Offshore state waters: California state waters offshore (within 3 nautical miles) are in CalGEM jurisdiction; federal OCS is in BOEM/BSEE jurisdiction. The South Ellwood and Platform Holly fields straddle this boundary.
7. Geothermal well counts are historical totals. Only a subset are currently producing. Filter on WellStatus='Active' for current operations.
8. Production/injection volumes are NOT in the REST API. They live in operator-level monthly reports (PDF/XLS) downloaded from the CalGEM website. Automated retrieval requires scraping or working from archive.org snapshots of the pubs_stats index.

Related Skills (Plugin Tie-ins)

• pnge-core:usgs-produced-waters — pull California subset of the USGS Produced Waters DB for geochemistry; cross-reference wells by API against CalGEM Layer 0 for operator/field context.
• pnge-core:usgs-minerals — Li and Mg commodity data, including the Salton Sea resource assessment in USGS Mineral Commodity Summaries 2025.
• pnge-federal-data:epa-regulatory — Envirofacts UIC_WELL cross-reference for Class II injection well compliance; California has EPA primacy for Class II programs so CalGEM is the primary regulator but EPA retains oversight.
• pnge-federal-data:netl-edx — DOE NETL critical-minerals datasets; search for "Salton Sea" and "geothermal lithium" to find integrated techno-economic models.
• pnge-core:pnge-literature — federated literature search (OpenAlex + CrossRef
  • USGS Pubs + DOE OSTI adapters) for technical reports from Berkeley Lab, Sandia, and PNNL on Salton Sea Li resource assessment, DLE chemistry, and CCS pilot integration with geothermal lithium extraction.

Reference Files

• references/salton_sea_li.md — KGRA boundaries, Li project operators, brine chemistry snapshot, and links to USGS and DOE resource assessments.
• references/well_data_access.md — detailed query recipes, field vocabularies, pagination patterns, and the CalWIMS → WellSTAR migration notes.
• references/golang_client.go — minimal Go client for WellSTAR queries with pagination, county/field filters, and CSV output.