Integrating Decision Support Models with Market and Non-Market Value Attributes for Platform Decommissioning: An Effective Approach for Resolving the Challenges Inherent at the Nexus of Science and Policy

Abstract

Abstract Many critical factors must be considered in determining the most feasible and appropriate options for decommissioning offshore oil and gas platforms, including alternatives from complete removal to partial removal with artificial reefing. Using financial-based cost/benefit analysis to evaluate decommissioning options neglects the complexities inherent in a successful platform decommissioning process, which includes non-monetary values such as the production of greenhouse gasses and the gains and/or losses of ecological services due to partial or complete removal. Multi-attribute decision analysis provides technically defensible consideration of both market and non-market values associated with the outcomes of rig decommissioning while allowing stakeholders to clearly and transparently investigate and evaluate the nexus between financial considerations and other factors (e.g., air/water quality, biological productivity, ocean access) that drive public policy. In California, the PLATFORM decision support model was a key component in helping a diverse group of stakeholders reach consensus on the preferred policy of partial removal and artificial reefing, which ultimately resulted in the creation of a public regulatory framework for rig decommissioning—the California Marine Resources Legacy Act. We describe how to use multi-variable decision analysis to facilitate offshore oil and gas platform decommissioning. We implemented decision analysis as a software tool (PLATFORM) to clarify and evaluate decommissioning alternatives against a comprehensive set of objectives, including both market and non-market values. Decommissioning options selected for in-depth analysis were complete platform removal and partial removal to 85 feet below the water line, with the remaining structure converted to an artificial reef. PLATFORM performed key analyses of the impacts of each option (e.g., on costs, fishery production, air emissions). The analysis found a near-consensus of stakeholders in support of partial removal and a "rigs-to-reefs" program. Decision support models, such as PLATFORM, are readily adaptable to support regulatory decision-making and alternatives analysis for decommissioning worldwide, including the North Sea, Australia, and Asia.