Product Overview

Summary: This Wellbore Stability Safe Operating Procedure provides a clear, step-by-step framework for planning, monitoring and controlling wellbore stability risks throughout drilling operations. It helps Australian drilling and petroleum operations maintain safe hole conditions, prevent well control incidents and avoid costly non‑productive time associated with stuck pipe, lost circulation and wellbore collapse.

Maintaining wellbore stability is critical to safe and efficient drilling operations in Australia’s onshore and offshore oil and gas, CSG and geothermal sectors. Unstable formations, inappropriate mud weights, poor hole cleaning and inadequate monitoring can quickly escalate into stuck pipe, lost circulation, kicks and even catastrophic well control events. This Wellbore Stability Safe Operating Procedure sets out a structured, repeatable process for identifying geomechanical risks, selecting appropriate drilling parameters, and continuously monitoring well conditions to keep the hole stable and the crew safe.

The SOP aligns with Australian WHS legislation and industry best practice, giving your teams a practical, field-ready document that links engineering decisions with safety-critical controls. It guides personnel through pre‑spud planning, real-time monitoring, response to early warning signs of instability, and clear escalation pathways when conditions deteriorate. By standardising how wellbore stability is managed across rigs and projects, your organisation can reduce non‑productive time, protect high-value assets, and demonstrate due diligence to regulators, JV partners and clients.

With a strong focus on communication, handover and documentation, this procedure also supports competency development and consistent supervision on site. It ensures that everyone—from the rig floor to the office—understands their role in maintaining wellbore integrity, managing interface risks between drilling contractors and operators, and responding effectively to instability events before they become incidents.

Key Benefits

• Reduce the risk of well control incidents, stuck pipe and wellbore collapse through a structured approach to stability management.
• Ensure compliance with Australian WHS duties by demonstrating systematic identification and control of wellbore stability hazards.
• Standardise decision-making and communication between office-based engineers and rig personnel during critical drilling operations.
• Minimise non‑productive time and costly remedial work by detecting and responding early to signs of instability.
• Improve training, competence and supervision by providing clear, role-specific responsibilities and checklists for wellbore stability control.

Who is this for?

• Drilling Engineers
• Wellsite Supervisors (Company Men)
• Toolpushers
• Drillers and Assistant Drillers
• Petroleum Engineers
• WHS Managers in Oil and Gas
• Onshore and Offshore Rig Managers
• Geomechanics Specialists
• Operations Managers – Drilling and Completions
• HSE Advisors – Resources and Energy Sector

Hazards Addressed

• Wellbore collapse leading to stuck pipe and loss of well control margins
• Kicks and potential blowouts due to inappropriate mud weight or loss of hydrostatic pressure
• Lost circulation and formation breakdown from excessive equivalent circulating density (ECD)
• Hole pack-off and differential sticking during tripping and circulation
• Unexpected over-pressured or under-pressured zones causing instability
• Equipment damage and dropped objects resulting from sudden overpull or pipe failure during stuck pipe events
• Fatigue and human error during high-risk, high-workload sections such as drilling through depleted or tectonically stressed formations
• Environmental harm from uncontrolled release of formation fluids or drilling muds

Included Sections

• 1.0 Purpose and Scope
• 2.0 Definitions and Key Terms (Wellbore Stability, ECD, Kick Indicators, etc.)
• 3.0 Roles and Responsibilities (Operator, Drilling Contractor, Service Companies, WHS Personnel)
• 4.0 Applicable Legislation, Standards and Company Requirements
• 5.0 Pre‑Spud Planning and Geomechanical Risk Assessment
• 6.0 Mud Weight, Fluid Design and Wellbore Strengthening Strategy
• 7.0 Drilling Parameters, Tripping Practices and Hole Cleaning Requirements
• 8.0 Real-Time Monitoring, Data Requirements and Stability Indicators
• 9.0 Early Warning Signs of Instability and Trigger Action Response Plans (TARPs)
• 10.0 Operational Controls for High‑Risk Zones (Depleted, Over-Pressured, Naturally Fractured Formations)
• 11.0 Managed Pressure and Underbalanced Drilling Considerations (If Applicable)
• 12.0 Stuck Pipe Prevention and Initial Response Procedure
• 13.0 Lost Circulation Prevention and Control Measures
• 14.0 Interface Management and Communication Protocols (Rig–Office, Shift Handover, Reporting)
• 15.0 Emergency Response and Well Control Escalation Pathways
• 16.0 Environmental Protection and Spill Prevention Considerations
• 17.0 Training, Competency and Verification of Understanding
• 18.0 Documentation, Records and Reporting Requirements
• 19.0 Audit, Review and Continuous Improvement of Wellbore Stability Practices

Legislation & References

• Work Health and Safety Act 2011 (Cth) and equivalent state and territory WHS Acts
• Work Health and Safety Regulations 2011 (Cth) – including provisions for high risk work and remote or isolated work
• Offshore Petroleum and Greenhouse Gas Storage (Safety) Regulations 2009
• NOPSEMA – Offshore Petroleum: Safety Case Guidance and Well Integrity Management expectations
• AS/NZS ISO 31000:2018 Risk management – Guidelines
• AS/NZS 4801:2001 Occupational health and safety management systems (superseded but still commonly referenced in industry)
• Safe Work Australia – How to Manage Work Health and Safety Risks Code of Practice
• API RP 59: Recommended Practice for Well Control Operations (used as an industry benchmark in Australian operations)
• API RP 92M: Managed Pressure Drilling Operations (where applicable to stability management)