Considerations in evaluating potential socioeconomic impacts of offshore platform decommissioning in California

Abstract

The 27 oil and gas platforms offshore southern California will eventually reach the end of their useful lifetimes (estimated between 2015 and 2030) and will be decommissioned. Current state and federal laws and regulations allow for alternative uses in lieu of the complete removal required in existing leases. Any decommissioning pathway will create a complex mix of costs, benefits, opportunities, and constraints for multiple user groups. To assist the California Natural Resources Agency in understanding these issues, we evaluated the potential socioeconomic impacts of the 2 most likely options: complete removal and partial removal of the structure to 85 feet below the waterline with the remaining structure left in place as an artificial reef-generally defined as a manmade structure with some properties that mimic a natural reef. We estimated impacts on commercial fishing, commercial shipping, recreational fishing, nonconsumptive boating, and nonconsumptive SCUBA diving. Available data supported quantitative estimates for some impacts, semiquantitative estimates for others, and only qualitative approximations of the direction of impact for still others. Even qualitative estimates of the direction of impacts and of user groups' likely preferred options have been useful to the public and decision makers and provided valuable input to the project's integrative decision model. Uncertainty surrounds even qualitative estimates of the likely direction of impact where interactions between multiple impacts could occur or where user groups include subsets that would experience the same option differently. In addition, we were unable to quantify effects on ecosystem value and on the larger regional ecosystem, because of data gaps on the population sizes and dynamics of key species and the uncertainty surrounding the contribution of platforms to available hard substrate and related natural populations offshore southern California.

A Decision Support Model for Platform Decommissioning: Successful Applications in California and Implications for Worldwide Use

“…• Quantified changes to access in square nautical miles for each option and each of five user groups (recreational and commercial fishing, non-consumptive boating, non-consumptive diving use (SCUBA), shipping • Estimated economic value for non-consumptive diving; data gaps prevented quantitative estimation for other uses • Classified user group preferences as pro, con, or neutral for each option; different commercial fishing gear groups had different preferences • Data gaps, large uncertainties, and small size of impacts relative to local economy restricted analysis to the immediate vicinity of platforms Kruse et al 2015 ؆Strict compliance؆: The original oil and gas leases required lessees to remove the platforms entirely at the end of their productive life and restore the seafloor to its original condition. Used as a surrogate for a broader set of perspectives related to stewardship, environmental restoration, minimization of long-term pollution risk.…”

“…The project team's domain experts developed separate modules to estimate decommissioning costs (Bressler and Bernstein 2015), fish production (Pondella et al 2015), socioeconomic effects (Kruse et al 2015), and air quality impacts (Cantle and Bernstein 2015) in collaboration with the project's decision modelers. Influence diagrams identify key variables, including data types, uncertainties (oval nodes), decisions (rectangular nodes), and result variables, with the influences represented as arrows between them.…”

A multi‐attribute decision analysis for decommissioning offshore oil and gas platforms

“…Model details are organized as a hierarchy of modules, each structured as an influence diagram (Figures and ). The project team's domain experts developed separate modules to estimate decommissioning costs (Bressler and Bernstein this issue), fish production (Pondella et al this issue), socioeconomic effects (Kruse et al this issue), and air quality impacts (Cantle and Bernstein this issue) in collaboration with the project's decision modelers. Each diagram identifies key variables, including data sources, uncertainties (oval nodes), decisions (rectangular nodes), and result variables, with the influences drawn as arrows between them.…”

“…It should not be surprising that a higher weight on compliance favors complete removal. The other attribute is ocean access, which favors complete removal because partial removal leaves the jacket at 85 feet below MWL, an underwater obstacle for some commercial fishers (Kruse et al this issue) that must be avoided. The remaining 7 variables, including cost weight, cost uncertainty, and all the environmental impacts, favor partial over complete removal, where a higher weight or value decreases the utility difference between partial and complete removal.…”

“…We applied these methods and conducted the analysis in a computer model, PLATFORM, implemented in Analytica (Lumina Decision Systems 2012). Companion articles in this series provide details of key scientific and economic inputs to the decision analysis, including decommissioning costs (Bressler and Bernstein this issue), impacts on fish production (Pondella et al this issue), air emissions (Cantle and Bernstein this issue), and socioeconomic impacts (Kruse et al this issue).…”