Production-Facility Emissions Reduction in Liquid-Rich Shales: An Update

Abstract

Summary Operators in unconventional shales are continuously looking for ways to reduce potential emissions from production facilities. This is especially challenging in liquid-rich regions, such as the Marcellus Shale. As regulations and various industry best practices evolve, facility designs and equipment must evolve as well. Facility-design improvements and successful operational procedures were examined to eliminate or significantly reduce emissions (Porter et al. 2016). By taking a proactive approach, operators can significantly reduce emissions. In a previous work (Porter et al. 2016), we discussed the key elements of a successful program: (1) a facility design and operational philosophy that considers emission controls, (2) a comprehensive maintenance program that addresses all unplanned or unintended releases encountered during optical-gas-imaging inspections and allows for feedback to facilitate corrective action, and (3) a focused plan for improving technology to diminish the quantity of future leaks. Applying enhanced technology and past experiences to older designs is often the most efficient measure for reducing potential emissions. While these elements are crucial, equally important is the historical defining and tracking of actual identified leaks and the documentation of corrective actions that were taken (Porter et al. 2016). This work further corroborates these key elements. Additional facility designs for maximum emissions reduction were compared to facility designs in our previous work (Porter et al. 2016), using calculated emissions for each scenario. As well production increases (owing to longer lateral drilling and enhanced stimulation practices), wellsite liquid handling and vapor control become challenging. Techniques for effectively controlling vapors and mitigating emissions were explored in detail, using an actual case study. Also, a previous leak-detection field study with preliminary data was updated with additional years of data, which yielded further clarification of emissions released on a field and pad level with resulting variations in time. Detailed data analysis compiled from inspections identified the most common areas where leaks occur within a production facility—the majority of which were located on atmospheric stock tanks. Data further demonstrated the effectiveness of higher-quality tank relief valves for reducing fugitive leaks. Production-facility emissions can be managed by using effective production-facility designs and technologies. The present work offers an improved understanding of how technological evolutions can support effective design solutions and processes in a modern shale-gas development (Porter et al. 2016).