Class Code 6235
Oil/Gas Wells – Drilling Or Redrilling/Install/Recovery Of Casing; Drilling Geothermal Wells
Class Code 6235 covers drilling and redrilling of oil and gas wells, installation or recovery of casing, and drilling of geothermal wells in California. The September 1, 2026 approved pure premium rate for this classification is $4.803 per $100 of payroll, which reflects the high-hazard nature of drilling operations.
What Class Code 6235 Covers
This classification applies to active drilling operations: rotary and cable-tool rigs drilling oil, natural gas or geothermal wells, plus operations to install or recover casing strings. It covers on-site crews engaged in drill floor and derrick work, tubular handling, rig-up/rig-down, mud system operation, and well-control activities during drilling or redrilling. Routine site support like road maintenance or administrative office staff are not part of 6235 and should be separately classified. Work that is strictly production, pump installation or well servicing/maintenance after drilling typically falls under different WCIRB classes; 6235 specifically addresses the dynamic, higher-risk phase of creating or re-entering the wellbore.
Who It Applies To
- Drilling contractors operating rotary or cable-tool rigs
- Drillers, assistant drillers, and derrickmen
- Roustabouts and roughnecks handling tubulars and casing
- Toolpushers and rig supervisors overseeing drilling operations
- Geothermal drilling firms and their on-site crews
Common Job Duties
- Operating drill floor equipment, rotary tables, top drives and Kelly/rotary systems
- Running, cementing, installing and recovering casing and liners
- Handling and tonging tubulars, slips, elevators and casing spools
- Monitoring mud systems, pumps, and solids control equipment
- Performing well-control operations, BOP testing and choke/manifold work
- Rig-up/rig-down, crane lifts, and moving heavy rig components
Common Injury Risks
Understanding the $4.803 Rate
The pure premium rate of $4.803 per $100 of payroll represents the portion of expected loss costs (medical + indemnity) assigned to payroll for this classification before company-specific adjustments. Insurers multiply this pure premium by your payroll to calculate expected loss dollars; the final premium you pay will also reflect your insurers expense load, your experience modification (EMR), audits, policy limits, and any state or carrier assessments.
Cal/OSHA Compliance Requirements
Drilling and geothermal operations must follow California Title 8 requirements, including a written Injury and Illness Prevention Program (8 CCR 3203) and the Heat Illness Prevention standard for outdoor work (8 CCR 3395). Employers must implement respiratory protection where gas exposures (H2S) are possible (8 CCR 5144), comply with hazard communication for drilling fluids and additives (8 CCR 5194), and follow permit-required confined space procedures and crane/hoist safety rules when applicable. Regular well-control training, BOP testing, lockout/tagout and documented inspections are critical to meet Cal/OSHA expectations.
How Key HR Helps Employers Under Class Code 6235
A PEO like Key HR can centralize payroll classification, ensure accurate reporting for class 6235, and provide injury-prevention programs tailored to drilling and geothermal hazards. Key HR coordinates claims management, return-to-work plans, and safety training (well-control, H2S awareness, confined space, PPE), which can reduce lost-time claims and improve your experience modification over time.
Get a QuoteFrequently Asked Questions
Does class 6235 include well servicing and production work?
No. Class 6235 specifically covers drilling, redrilling and casing installation/recovery and geothermal drilling. Routine well servicing, pumping-unit maintenance, production operations and lease-site maintenance are classified separately and typically carry different risk profiles and rates.
What can I do to lower workers' comp costs for drilling crews?
Focus on measurable controls: documented well-control and BOP testing, pre-job hazard analyses, formal H2S and confined-space programs, crane and lifting safety, and rigorous tubular-handling procedures. Consistent training, drug/alcohol testing, PPE enforcement, timely incident investigation and active return-to-work programs all reduce claims and improve your EMR.
Are geothermal drilling crews treated the same as oil and gas drilling under 6235?
Yes. WCIRB class 6235 explicitly includes drilling of geothermal wells. While the geology and some hazards differ, the classification covers on-site drilling activities, casing work and related risks for geothermal operations.
Quick Facts
- Class Code
- 6235
- Classification
- Oil/Gas Wells – Drilling Or Redrilling/Install/Recovery Of Casing; Drilling Geothermal Wells
- Pure Premium Rate
- $4.803 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
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