Considering economic impacts in comparative assessment of decommissioning options for fixed offshore structures: insights from the IOGP study

Decommissioning decisions for fixed offshore structures typically weigh environmental, safety, societal and technical considerations via Comparative Assessment or Multi-Criteria Decision Analysis. Economic impacts on national value, supply chains and fiscal outcomes are often treated implicitly, framed as cost-avoidance by operators. The International Association of Oil and Gas Producers (IOGP) conducted a study to explicitly evaluate the economic impacts of decommissioning options for steel piled jackets and concrete gravity-based structures on the UK and Norwegian Continental Shelves. Using a bespoke economic model with inputs from industry workshops and subject-matter experts, the study quantified direct and indirect effects (including supply-chain activity, household spending and tax generation) under options ranging from full removal to partial removal/toppling, within OSPAR Decision 98/3 and International Maritime Organization framework constraints. The results indicate that partial removal options can provide greater overall value to national economies than full removal, primarily through enabling governments to reallocate a portion of decommissioning expenditure to higher-value public investments. Heavy lift campaigns were identified as the most influential cost driver; increasing domestic participation in heavy lift and onshore disposal can magnify national impacts by 20–30% or more. IOGP recommends that economic impact be systematically included in decision-making processes, alongside other criteria, to support balanced, evidence-based decommissioning decisions.