Comparative legal analysis reveals intensifying regulatory oversight, expanding financial assurance requirements and growing integration of environmental considerations in offshore oil and gas end-of-life planning

Decommissioning has shifted from a technical afterthought to a central regulatory and financial priority across major offshore jurisdictions.

Across mature and emerging basins alike, regulators are refining approval processes, strengthening financial assurance requirements and expanding liability chains to ensure that end-of-life obligations are funded, executed and monitored in full.

What was once treated as a technical closure phase is now a complex, capital-intensive and highly regulated discipline with direct implications for balance sheets, licence security and state revenues.

The International Guide to Offshore Decommissioning by CMS analyses 10 key jurisdictions, including Angola, Australia, Brazil, Bulgaria, Malaysia, the Netherlands, Norway, Poland, Romania and the UK, setting out the regulatory architecture, allocation of responsibility and enforcement frameworks governing offshore oil and gas asset retirement.

REGULATORY ARCHITECTURE & ALLOCATION OF LIABILITY

In Angola, Presidential Decree No 91/18 of 10 April and the Petroleum Activities Law establish detailed procedures for well abandonment and facility dismantling.

Contractors must submit a provisional decommissioning plan accompanied by an Environmental Impact Study, followed by a final plan, at least, 24 months before reaching economic limit or cessation of production.

Oversight is exercised by the National Concessionaire and the Supervisory Authority through inspections and audits.

Contractors are responsible for accidents arising during or after abandonment where negligence or wilful misconduct is established, and must restore wells to a definitively abandoned state.

Australia’s Offshore Petroleum and Greenhouse Gas Storage Act 2006 imposes primary responsibility on the registered titleholder, with complete removal of structures forming the "base case" unless an alternative delivers equal or superior environmental outcomes.

Although no statutory security must be lodged with the Commonwealth, titleholders must maintain financial assurance sufficient to meet all decommissioning obligations.

The Offshore Petroleum (Laminaria and Corallina Decommissioning Cost Recovery Levy) Act 2022 further enables recovery of Commonwealth expenditure through a temporary levy.

Brazil operates a multi-agency system involving the National Agency of Petroleum, Natural Gas and Biofuels (ANP), the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA), the Brazilian Navy and the National Nuclear Energy Commission.

Liability is joint and several among consortium members and extends through post-monitoring phases.

Administrative sanctions include fines and suspension or revocation of rights, while environmental breaches may trigger civil and criminal liability.

Bulgaria’s Underground Resources Act assigns oversight to the Minister of Energy and the Minister of Environment and Waters.

Operators must provide financial guarantees covering waste management, land recultivation and emergency measures.

Sanctions for non-compliance range from BGN 10,000 to BGN 100,000, increasing significantly for repeated violations.

Malaysia administers abandonment through PETRONAS and the Jawatankuasa Kerja Zon Ekonomi Eksklusif.

Production Sharing Contract contractors must plan for decommissioning from the development stage, submit abandonment plans for approval and conduct post-removal surveys.

Environmental compliance is governed by the Environmental Quality Act 1974. Breaches may result in fines of up to RM500,000 for serious offences, potential imprisonment for officers and recovery of remediation costs.

In the Netherlands, offshore decommissioning is regulated principally under the Mining Act and related decrees.

The Minister of Economic Affairs and Climate Policy oversees approvals for abandonment and removal.

Licence holders are required to submit a decommissioning plan detailing technical measures, environmental considerations and timelines.

Liability remains with the licence holder, and joint and several responsibility may arise among co-licensees.

Norway’s regime is governed by the Petroleum Act and administered by the Ministry of Energy and the Norwegian Petroleum Directorate.

Licensees must submit a cessation plan, including a decommissioning proposal and impact assessment, typically two to five years before production ceases.

The Ministry determines whether facilities must be removed, left in situ or repurposed, following consultation and parliamentary consideration where required.

Licensees are jointly and severally liable for decommissioning costs, and financial arrangements must ensure the state is not exposed to unfunded obligations.

Poland regulates offshore decommissioning under the Geological and Mining Law and maritime legislation.

Concession holders are required to decommission installations and restore the site in accordance with approved plans. The competent minister oversees compliance, and environmental authorities may impose additional requirements.

Financial security instruments are required to guarantee performance of obligations.

Failure to comply may result in administrative penalties, revocation of concessions and enforcement of guarantees.

Romania’s offshore oil and gas framework, including the Offshore Law and petroleum legislation, places responsibility for decommissioning on concession holders.

Operators must prepare and submit decommissioning programmes detailing technical and environmental measures.

Financial guarantees are required to secure performance of decommissioning obligations, with liability persisting until competent authorities confirm satisfactory completion.

In the UK, the Petroleum Act 1998 establishes a robust decommissioning regime overseen by the Secretary of State and the North Sea Transition Authority. Section 29 notices may be served on licensees and other associated parties, requiring submission and execution of decommissioning programmes.

Approved programmes detail removal, waste management and environmental restoration measures, and financial assurance arrangements are scrutinised to protect the Exchequer from exposure. Civil sanctions and cost recovery powers reinforce compliance.

FINANCIAL EXPOSURE, MARKET SCALE & STRATEGIC ADJUSTMENT

The financial scale of offshore decommissioning is most pronounced in Brazil, where projections published in 2024 anticipate investments exceeding BRL 27 billion through 2025 for removal or deactivation of mature offshore fields.

This level of activity is reshaping contractor markets, logistics planning and capital allocation strategies. Petrobras’ 2024 announcement of a reduction of approximately $1.1 billion in its 2025–2029 decommissioning budget illustrates the budgetary pressures inherent in large-scale retirement programmes.

In the UK and Norway, mature North Sea infrastructure is entering advanced decommissioning phases.

Joint and several liability among licensees, combined with rigorous financial assurance expectations, has driven early provisioning and continuous reassessment of cost estimates.

Regulatory authorities retain broad powers to require additional security where financial capacity is questioned.

The Netherlands similarly emphasises cost transparency and security, with licence holders expected to demonstrate adequate financial resources to meet projected liabilities.

In Poland and Romania, emerging offshore sectors are embedding decommissioning planning requirements at an early stage of field development, reflecting lessons drawn from more mature basins.

Australia’s cost recovery levy mechanism highlights the policy tools available where legacy assets create fiscal exposure.

Trailing liability provisions ensure that former titleholders and related entities may be called upon to fund remediation, reinforcing lifecycle accountability.

Angola’s escrow-based abandonment funds and sovereign investment requirements, Malaysia’s abandonment cess structures and Brazil’s comprehensive guarantee instruments each represent jurisdiction-specific adaptations of the same principle: ring-fenced funding must be in place before liabilities crystallise.

Environmental oversight is integrated across all ten jurisdictions. Impact assessments, post-removal surveys and monitoring obligations form standard components of approved plans.

Brazil’s IBAMA, Norway’s environmental authorities, the UK’s environmental regulators and equivalent bodies in other jurisdictions maintain supervisory roles that extend beyond physical removal to long-term seabed condition and pollution prevention.

Energy-transition considerations are beginning to intersect with decommissioning frameworks.

Brazil’s Law No 15.097/2025 establishes a framework for offshore renewable electricity generation, permitting consideration of asset reuse or coexistence in decommissioning planning.

Norway and the UK provide for ministerial discretion in determining whether installations may be left in situ or repurposed, subject to environmental assessment and public interest evaluation.

In other jurisdictions, including Angola, Bulgaria and Malaysia, no explicit linkage is yet embedded in legislation, although decommissioning planning must still account for environmental restoration standards.

Across the 10 jurisdictions analysed, a consistent pattern emerges: Decommissioning is governed by detailed statutory frameworks, enforced through joint and several liability, underpinned by mandatory financial security and subject to escalating regulatory scrutiny.

As investment commitments run into tens of billions of local currency units across mature basins, the technical execution of removal activities is inseparable from legal compliance, financial provisioning and strategic planning.

For operators, investors and policymakers, offshore decommissioning is no longer a terminal phase but a defining element of upstream asset governance.