KNOWLEDGE HUB
Decommissioning Programme
The Central Regulatory Document for Offshore Oil and Gas Decommissioning
In the complex lifecycle of an offshore asset, the Decommissioning Programme (DP), often referred to as a Decommissioning Plan, serves as the central management tool and the primary regulatory document required to oversee the transition from production to removal. It is a comprehensive framework produced to ensure that the decommissioning of offshore oil and gas assets is completed in strict accordance with legal requirements.
Once approved, the DP is not merely a plan; it becomes a legal obligation in many regions.
The Regulatory Roadmap (UK example)
In the UK, the Offshore Petroleum Regulator for Environment and Decommissioning (OPRED) is the primary regulator of the Decommissioning Programme.
The roadmap involves several critical stages mandated by the UK Government:
Identification
Defining all infrastructure to be decommissioned.
Official Submission
Submitting the detailed plan to the Secretary of State.
Public Consultation
In the UK, the plan is opened to government bodies, non-governmental organisations, and stakeholders for feedback.
Approval or Rejection
OPRED evaluates the submission and consultation responses before reaching a final decision.
The Materials Inventory
The “backbone” of any UK Decommissioning Programme is the Materials Inventory. This body of work identifies exactly what exists on the seabed and the platform at the point of decommissioning. This is a significant undertaking because many assets modified over a 50-year lifecycle often differ greatly from their original design specifications.
The inventory includes a detailed breakdown of materials, weights, design outlines, the number of wells, and the specific lengths and sizes of pipelines.
Supporting Pillars: Comparative Assessment and Environmental Statements
A Decommissioning Programme is supported by two primary documents that justify the chosen methods to the regulator:
Comparative Assessment (CA)
Required for subsea infrastructure where full removal may not be the optimal solution, the UK process entails a seven-stage assessment. This evaluates options against five main criteria: environmental impact, economic cost, societal impact, safety, and technical feasibility.
Environmental Statement (ES)
This document outlines the potential impact of activities on the marine environment — from the seabed and mammals to the water column and bird populations. It quantifies the scale of the impact and details necessary modifications to protect the ecosystem.
Execution, Monitoring, and Compliance (UK example)
Once the DP is approved, it serves as the legal template for all future works. OPRED assigns a specific Case Manager to each UK operator to follow the project from preparation through execution to final closeout.
A critical component of the DP is the Waste Management Plan, which, in the UK, targets high recycling figures — often exceeding 96% — for materials brought back to shore. The DP also frames the project schedule, allowing the UK public and regulators to see the overall duration of activities and the specific windows for heavy-lift operations.
Derogations: The Exception to the Rule
While the UK regulatory expectation is a clear seabed, some challenging infrastructure may be eligible for a derogation. This applies to heavy steel jacket footings or concrete gravity base structures where full removal presents extreme safety risks or disproportionate costs.
In the UK, operators must first submit a full removal case; only after OPRED concludes that full removal is not possible will the formal derogation process begin. Notably, any infrastructure installed in the UK after 1999 is expected to be fully removed.
Professional Decommissioning Learning
Understanding the intricacies of the Decommissioning Programme is essential for professionals to ensure regulatory compliance and operational efficiency.
In the Lean Decom training course delivered by Gareth Jones, who is the Chair of Decom Mission and the Head of Decommissioning for Xodus, you will acquire a detailed walkthrough of how to construct these programmes. Complementary insights from the OPRED regulations session provide the necessary decision context regarding the regulatory requirements and the foundations of decommissioning planning.