Advancing Understanding of Emissions from Oil and Natural Gas Production Operations to Support EPA’s Air Quality Modeling of Ozone Non-Attainment Areas; Final Summary Report
Matichuk, R., G. Tonnesen, A. Eisele, E. Thoma, Mike Kosusko, M. Strum, AND C. Beeler. Advancing Understanding of Emissions from Oil and Natural Gas Production Operations to Support EPA’s Air Quality Modeling of Ozone Non-Attainment Areas; Final Summary Report. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-17/224, 2016.
This report summarizes work done on an EPA R8 RARE project that advanced measurement methods and speciated emissions information for the upstream oil and gas sector. The work consisted of two parts: (1) pilot testing of experimental optical remote sensing system to investigate the efficacy of enclosed combustor control devices on oil and gas well pads in the DJ Basin and (2) work to augment the SPECIATE database for the oil and gas sector. This report documents the activities for these efforts. .
Executive Summary Environmentally responsible development of oil and gas assets requires well-developed emissions inventories and measurement techniques to verify emissions and the effectiveness of control strategies. To accurately model the oil and gas sector impacts on air quality, it is critical to have accurate activity data, emission factors and chemical speciation profiles for volatile organic compounds (VOCs) and nitrogen oxides (NOx). This report describes a U.S. Environmental Protection Agency (EPA) Office of Research and Development (ORD) Region 8 Regional Applied Research Effort (RARE) effort executed in Fiscal Year (FY) 2014 to FY 2016 that aimed to improve information on upstream oil and production emissions and identify areas where future work is needed. The project involved both field activities and data analysis and synthesis work with emphasis on product-related VOC emissions from well pads. In oil and gas basins with significant condensate and oil production, VOC emissions from well pads primarily arise from the separation of gas and liquid products and the storage process, with the control of emissions usually accomplished by enclosed combustion devices (ECDs), such as flares. Fugitive emissions of VOCs can originate from leaks and from potentially ineffective control systems. In the case of ECDs, byproducts of incomplete combustion may produce more highly reactive ozone precursor species. For both compliance and scientific purposes, the ability to assess ECD operations from off-site vantage points is important. Similarly, continued improvements to the United States Environmental Protection Agency’s (EPA’s) SPECIATE database, which is used to develop emissions inventories for air quality models, with updated VOC emissions profiles for both leaks and ECDs for the oil and gas sector is a clear and important need. The field work for this project consisted of a five-day pilot test of off-site remote sensing systems to assess emissions from ECDs. The results of this demonstration indicated that it may be possible to effectively assess the operational states of ECDs for compliance purposes, but new technology [subject of the current EPA Small Business Innovation Research (SBIR) effort] will likely be required. Of ten well pads investigated, at least one demonstrated evidence of improper ECD operations, but we were not able to quantify the emissions of highly reactive VOCs from this device with a high level of certainty. This project identified a need for additional research to update emission speciation profiles for both properly operating and malfunctioning ECD systems and to improve our understanding of the prevalence of the latter. The data synthesis portion gathered information on VOC emissions from multiple internal and external projects. These data were utilized to develop process-related VOC speciation profiles that were incorporated into EPA’s SPECIATE database for multiple basins and to improve SPECIATE’s representation of oil and gas processes. This report and associated Excel spreadsheet provides background information on these efforts, summarizes results, and provides information on areas for potential future work.