Designing the Ideal Offshore Platform Methane Mitigation Strategy

Abstract

Abstract Description of the Proposed Paper: Methane is a powerful greenhouse gas and the primary component of natural gas and minimizing methane emissions creates both environmental and commercial benefits. Offshore production platform air emissions have been studied and characterized in detail by the U.S. Minerals Management Service (MMS)1, and the U.S. Environmental Protection Agency's (EPA) Natural Gas STAR Program has gathered information on methane emission reduction technologies and practices applicable to these facilities. This paper analyzes and summarizes methane emission volumes and sources from offshore production platforms, outlines mitigation technologies and practices, and provides a methodology for conducting full cost-benefit economic analyses to prioritize mitigation actions to yield the maximum environmental benefits at the lowest cost. The information presented can help companies better understand emissions from their offshore facilities and provide guidance they can use to optimize their own operations. Application: Worldwide offshore oil and gas production operators can use this approach to improve their current methane emissions inventories and identify mitigation technologies and practices that could be used to reduce emissions at existing facilities or be considered in the design of new platforms as a way to minimize or prevent potential methane emissions. Results, Observations, and Conclusions: MMS provides a significant body of knowledge about overall operations and methane emissions from offshore oil and natural gas production platforms. New research and data gathering was utilized to develop a comprehensive analysis of methane emissions from individual platform operations. In doing so, this information was synthesized for the first time in a comprehensive way to identify mitigation technologies and practices that could be applied to the most significant emission sources. Marginal abatement cost curve analyses were then developed to prioritize mitigation actions. This analysis indicated that up to 85% of an individual platform's methane emissions can be reduced cost-effectively through replacement of centrifugal compressor wet seals with dry seals; routing vent sources such as storage tanks, dehydrators, and pig launcher to a vapor recovery system; and implementing a directed inspection and maintenance program to target fugitive emissions. Significance of Subject Matter: Optimizing platform design to reduce methane emissions contributes climate change benefits, given methane's role as a greenhouse gas, and also enhances operational safety on offshore platforms. These pillars of environmental and safety benefits, along with economic benefits of conserving and utilizing a valuable clean energy source, contribute to overarching principles of corporate social responsibility.