Product Overview

Summary: This Offshore Platform Decommissioning Safe Operating Procedure provides a structured, safety-first approach to planning and executing the removal, dismantling and disposal of offshore oil and gas infrastructure. It supports Australian operators to manage complex marine, structural and environmental risks while maintaining WHS compliance, project control and stakeholder confidence throughout the decommissioning lifecycle.

Decommissioning an offshore platform is one of the highest-risk phases in an asset’s lifecycle, combining heavy lifting, marine operations, complex isolations, hazardous substances and legacy integrity issues in a dynamic offshore environment. This Safe Operating Procedure sets out a clear, end‑to‑end framework for safely planning, preparing and executing decommissioning works in Australian waters, from initial feasibility and regulatory approvals through to plug and abandonment interfaces, topsides and jacket removal, subsea infrastructure recovery and final site remediation. It provides a practical roadmap that integrates WHS obligations with environmental, maritime and petroleum regulatory requirements, helping duty holders demonstrate due diligence and effective risk management.

The SOP translates high-level decommissioning strategies into step-by-step operational controls that frontline personnel can follow. It covers critical elements such as structural condition assessment, safe access and egress, energy isolation and verification, SIMOPS coordination, marine spreads and lifting operations, diving and ROV activities, hazardous materials management (including NORM, asbestos and hydrocarbons), waste classification and onshore disposal pathways. By standardising roles, communication protocols, permit-to-work processes and emergency arrangements, the document reduces ambiguity between operators, contractors and vessel crews, minimises the likelihood of incidents, and supports predictable project delivery in line with Australian WHS law and regulator expectations.

For Australian businesses transitioning assets at the end of field life, this SOP helps bridge the gap between engineering studies and safe execution offshore. It provides a defensible, auditable procedure that can be tailored to specific platforms and campaigns, underpinning workforce training, contractor onboarding, toolbox talks and ongoing assurance activities. The result is a safer, more efficient and more compliant decommissioning program that protects workers, the marine environment and corporate reputation.

Key Benefits

• Ensure a structured, defensible approach to offshore decommissioning that aligns with Australian WHS and petroleum regulatory expectations.
• Reduce the risk of serious incidents involving structural collapse, dropped objects, vessel collisions and uncontrolled releases of hydrocarbons or hazardous substances.
• Streamline coordination between operators, marine contractors, drilling contractors, divers and onshore support teams through clearly defined roles and communication protocols.
• Improve project predictability by standardising planning, risk assessment, permit-to-work and change management processes across all decommissioning phases.
• Demonstrate due diligence to regulators, joint venture partners and stakeholders through documented, auditable decommissioning procedures and control measures.

Who is this for?

• Offshore Installation Managers (OIMs)
• Decommissioning Project Managers
• WHS Managers and Advisors
• Offshore Construction and Marine Supervisors
• HSE and Risk Managers
• Offshore Operations Engineers
• Diving Supervisors and ROV Supervisors
• Marine Vessel Masters and Barge Superintendents
• Maintenance and Integrity Engineers
• Contractor and Subcontractor Managers

Hazards Addressed

• Structural instability and collapse of ageing offshore platforms during cutting, lifting and dismantling activities
• Dropped objects from cranes, lifting operations and deck activities impacting personnel, vessels or subsea infrastructure
• Vessel collision and marine operations risks, including station-keeping failures and simultaneous operations (SIMOPS) conflicts
• Exposure to hydrocarbons, process chemicals and legacy contaminants during flushing, cleaning and dismantling works
• Presence and handling of hazardous materials such as asbestos-containing materials (ACM), naturally occurring radioactive material (NORM) and lead-based coatings
• Confined space entry risks in tanks, columns, caissons and enclosed modules
• Working at height on exposed decks, flare booms and derricks in adverse offshore weather conditions
• Failure of energy isolation, lock-out tag-out and verification leading to unexpected energisation or release of stored energy
• Diving and ROV operational hazards, including entanglement, differential pressure, poor visibility and subsea cutting operations
• Manual handling and ergonomic injuries from handling heavy or awkward components in constrained offshore spaces
• Fire and explosion risks arising from hot work, residual hydrocarbons and ignition sources
• Environmental incidents such as spills, debris release or seabed contamination during removal and transport activities
• Fatigue, stress and reduced situational awareness associated with extended offshore rosters and complex project timelines

Included Sections

• 1.0 Purpose, Scope and Application
• 2.0 Definitions and Abbreviations
• 3.0 Regulatory and Standards Framework (WHS, NOPSEMA, AMSA and Environmental Requirements)
• 4.0 Roles, Responsibilities and Competency Requirements
• 5.0 Decommissioning Strategy, Planning and Engineering Interface
• 6.0 Hazard Identification, Risk Assessment and ALARP Demonstration
• 7.0 Interface Management and SIMOPS Coordination (Drilling, Production, Marine, Diving and Construction)
• 8.0 Energy Isolation, Lock-Out Tag-Out and Verification Procedures
• 9.0 Structural Integrity Assessment and Access Arrangements
• 10.0 Marine Operations and Vessel Management (Mooring, Positioning and Transfer)
• 11.0 Lifting Operations, Rigging and Dropped Object Prevention
• 12.0 Diving and ROV Operations Control Measures
• 13.0 Confined Space Entry and Permit-to-Work Requirements
• 14.0 Management of Hazardous Materials (Hydrocarbons, NORM, Asbestos and Coatings)
• 15.0 Waste Management, Segregation, Transport and Onshore Disposal
• 16.0 Environmental Protection and Spill Prevention Measures
• 17.0 Personal Protective Equipment (PPE) and Safety Equipment Requirements
• 18.0 Communication, Toolbox Talks and Shift Handover Protocols
• 19.0 Emergency Preparedness and Response (Man Overboard, Fire, Structural Failure, Medical Emergencies)
• 20.0 Change Management, Deviations and Stop-Work Authority
• 21.0 Training, Induction and Competency Verification
• 22.0 Monitoring, Inspection, Audits and Continuous Improvement
• 23.0 Records, Reporting and Documentation Control
• 24.0 Post-Decommissioning Site Verification and Close-Out

Legislation & References

• Work Health and Safety Act 2011 (Cth) and model Work Health and Safety Regulations
• Offshore Petroleum and Greenhouse Gas Storage Act 2006 (Cth) and associated regulations
• NOPSEMA – Offshore Petroleum Facility Safety Case Guidance and Environment Plan Guidance
• Safe Work Australia – Code of Practice: How to Manage Work Health and Safety Risks
• Safe Work Australia – Code of Practice: Managing the Risk of Falls at Workplaces
• Safe Work Australia – Code of Practice: Confined Spaces
• Safe Work Australia – Code of Practice: Hazardous Manual Tasks
• AS/NZS ISO 45001:2018 Occupational health and safety management systems
• AS/NZS 4994 series: Temporary edge protection for construction and general use
• AS 2865: Confined spaces
• AS/NZS 1891 series: Industrial fall-arrest systems and devices
• AS 2550 series: Cranes, hoists and winches – Safe use
• Marine Order 21 (Safety and emergency arrangements) under the Navigation Act 2012
• Relevant AMSA Marine Orders relating to offshore support vessels and marine operations