It is the 3rd of the month in Bakersfield and your phone buzzes with a CalGEM notice. Two steam injectors on a Kern County pattern read zero for the prior month, and the auditor wants an explanation by end of week. The pumper swears he logged the meters. The meter card is nowhere in the office.
TL;DR: CalGEM (the agency formerly called DOGGR) collects monthly per-well production, injection, and well-status data from every California operator through WellSTAR. Filings are due the last day of the month following production. GreaseBook captures the gauges, run tickets, steam and water injection reads, and idle-day flags in the field so the WellSTAR upload is an export, not a reconstruction. The filing itself still goes through WellSTAR with the operator’s signature. This page is the California piece of the state production reporting framework that covers monthly operator filings across the country.
Operators who have been in California oil for 10+ years still call it DOGGR. The Division of Oil, Gas, and Geothermal Resources was renamed the California Geologic Energy Management Division (CalGEM) on January 1, 2020, but the name stuck because nobody rewrote their spreadsheets. The reporting is still real, the audit posture is serious, and California is not the place to guess.
DOGGR Is Now CalGEM
First, the name. DOGGR was the state agency regulating oil and gas production from the 1950s until 2020. Senate Bill 551 (signed 2019) renamed it CalGEM and expanded its mandate to include geologic energy management more broadly. The reporting requirements for operators did not fundamentally change with the rename, but the agency’s public-facing identity did.
If you are searching for “DOGGR monthly production report,” what you are really looking for is the current CalGEM monthly production report, filed through WellSTAR.
What CalGEM Requires Monthly
For every active well, California operators report monthly:
- Oil or condensate produced (barrels)
- Gas produced (MCF), including casinghead
- Water produced (barrels)
- Water injected for waterflood or saltwater disposal wells
- Steam injected for steamflood operations (significant in Kern County heavy oil)
- Gas injected for gas lift or pressure maintenance
- Days produced or injected each month
- Well status: active, idle, shut-in, plugged
Idle well reporting is a particular focus in California. The state has tightened enforcement on long-term idle wells since 2018, and operators with idle wells face annual fees and, depending on the idle count, required idle well management plans. CalGEM’s monthly data is how the state tracks idle status.
Who Files and When
The operator of record for each well is responsible for CalGEM reporting. Monthly production reports are due by the last day of the month following production. March production is due by the end of April. Filing goes through WellSTAR at wellstar-public.conservation.ca.gov.
California also requires an annual Form OG103 summary, but the heavy lift is the monthly WellSTAR submission.
The Field Data Behind the CalGEM Filing
CalGEM’s WellSTAR wants well-by-well numbers. That means the data chain looks like this:
- Pumper gauges: tank inventory by lease, temperature-corrected and BS&W-adjusted.
- Run tickets: every transport pull, tied to the correct lease and API number.
- Meter readings: gas, water injection, steam injection. California steamfloods have precise steam metering requirements at each injector.
- Well status flags: if a well went idle on the 7th, that shows up on the monthly as 6 days active and 24 days idle.
- Purchaser statements: reconciled against field totals before submission.
For California operators, the steam and water injection pieces are what distinguish the filing from states like Oklahoma or Texas. Kern County steamfloods have dozens of injectors per pattern, each with a monthly injection volume and temperature. Miss a meter read, and the monthly filing is wrong before it ever gets to WellSTAR. Operators managing multi-state production filings learn quickly that California’s steam and idle-day requirements have no equivalent in most other jurisdictions.
How GreaseBook Fits California Operator Workflows
GreaseBook captures the daily gauges, run tickets, water and steam injection readings, and downtime tags in the field. On the operator side, the data rolls up well-by-well in a layout that mirrors what CalGEM’s WellSTAR wants: oil produced, water produced, gas produced, days produced, well status.
GreaseBook does not submit to WellSTAR. That submission is owned by the operator and their California filer. What GreaseBook solves is the upstream data collection problem: the gauges that never made it to the accountant, the meter reads the pumper forgot to text over, the downtime that nobody tagged.
A small Kern County operator with 22 wells across two leases described the difference this way: “We used to spend the first two weeks of every month rebuilding last month from pumper notebooks. Now the rollup is done on the 2nd.”
GreaseBook gives California operators real-time pumper data so monthly WellSTAR filings are built on numbers you trust.
See how GreaseBook works →Common Mistakes on California Monthly Reporting
- Idle well status not flagged. A well that went idle mid-month still has to be reported that way. Leaving it on “active” creates an inconsistency that CalGEM audits will find.
- Steam injection volumes skipped or estimated. Steamflood operators have to hit the injector meter readings. Estimation is not a California-approved method.
- Wrong API number tied to a run ticket. California wells are reported by API, not just by lease. A run ticket filed under the wrong API misstates production at the well level even if the lease total is right.
- Purchaser reconciliation skipped. The oil purchaser reports their pulls to CalGEM as well. If your number and theirs disagree, the mismatch shows up.
- Annual summary inconsistent with monthlies. The annual Form OG103 should reconcile to the 12 monthly filings. If it doesn’t, you get a letter.
Phrases to Eliminate in CalGEM Correspondence
The language operators use when something goes wrong shapes the auditor’s response. Measurement language closes findings. Vague or blame language invites scrutiny.
| Instead of… | Say… | Why |
|---|---|---|
| “The well was idle for a while last year” | “Well API 04-XXX logged 214 idle days in 2025, documented on the monthly OPR submissions” | CalGEM tracks idle days precisely and ties them to idle well fees and management plans |
| “The pumper forgot to read the steam meter” | “Steam injection volume for injector I-7 is reconstructed from the adjacent-day readings and the meter totalizer on file” | Never tell CalGEM a record is missing if you can reconcile it. Show the reconstruction. |
| “We estimated the flare volume” | “We applied the documented calculation method cited in our OPR submission for flare volumes during that period” | “Estimated” without a method is an audit trigger in California. A cited method passes. |
| “The purchaser number is probably close” | “Purchaser statement for that period reconciles to field gauge totals within 0.3 percent” | CalGEM cross-checks operator filings against purchaser data. Numeric reconciliation closes the gap. |
Identity Framing: What the Best California Operators Do
The best California operators flag idle days the week they happen, cite the steam injection calculation method before the auditor asks, and reconcile to the purchaser statement before WellSTAR sees the upload. The monthly filing is a rhythm, not a fire drill.
Wrong Fit for This Page
If you are Chevron, Aera, or a California major with a full integrated production accounting stack that generates CalGEM-ready outputs, you don’t need help on the data collection side. This page is for the independent California operator with a handful of leases, a pumper or two, and a monthly WellSTAR deadline that keeps sneaking up.
FAQ
Does GreaseBook file my OG100/OG110 with CalGEM?
No, and it shouldn’t. CalGEM filing still goes through WellSTAR. What GreaseBook does is make the WellSTAR upload take 15 minutes instead of 3 days by giving you clean per-well monthly production, well status, and injection data ready to submit.
Is DOGGR the same as CalGEM?
DOGGR was renamed to CalGEM on January 1, 2020. The reporting requirements for operators carried over. “DOGGR monthly production report” and “CalGEM monthly production report” refer to the same filing.
When is the monthly California production report due?
Monthly production reports are due by the last day of the month following production. April production is due by the end of May.
What is WellSTAR?
WellSTAR is CalGEM’s electronic filing system for production reports, well permits, and related filings. The portal is wellstar-public.conservation.ca.gov. All operators file here.
Do idle California wells still have to report?
Yes. Idle wells report monthly with zero production and an idle status flag. California also charges annual idle well fees and can require idle well management plans depending on how many idle wells an operator carries.
Related Pages
GreaseBook also automates state production reports in Mississippi, Alabama, Wyoming, and Michigan for operators filing across state lines.
- Oil and gas regulatory production reports: the full state-by-state guide to monthly filings.
- New Mexico OCD Form C-115: New Mexico’s equivalent for operators active in both states.
- Wyoming Form 2: Wyoming monthly production reporting for operators with Rocky Mountain acreage.
GreaseBook captures California field data in real time, so you file from numbers that already match the purchaser statement. Because CalGEM's late-filing penalty compounds faster than the oil does.
See how GreaseBook works for California operators →