Air Emission Characterization for Hydraulic Fracturing Operations in the United States

Abstract

Advanced petroleum and natural gas production technologies are increasingly used to help meet the demand for energy in both the United States and globally. As conventional resources become more scarce, research and innovation by the oil and gas industry has resulted in techniques for tapping unconventional resources, including hydrocarbons trapped in shale formations found in a number of locations throughout the United States. A key technology for accessing such resources is hydraulic fracturing (fracking), which has transformed natural gas production over the past several years and is also being applied for oil production. These new energy supply technologies also bring new environmental management challenges. Among the issues of concern are the air pollution emissions from fracking operations and whether they can potentially impact air quality at well sites and in surrounding communities. A significant opportunity exists to improve the sustainability of energy production by reducing the air emissions from fracking operations. This Master’s Project focuses on the characterization and modeling of these air emissions to help improve environmental management efforts by the industry and to inform the application of regulations for guiding efforts to reduce emissions. The emissions addressed include criteria air pollutants and their precursors. The work involved identifying major sources of emissions during fracking operations, evaluating current models used for air emissions characterization, and developing refinements to the models to enable better emissions management. The project team travelled to a well site and to testing facilities to learn about operations in two different shale formations and to gather data needed to improve emissions characterization. These visits enabled the team to gain a deeper understanding of the nature of fracking equipment, operations and air emissions test protocols. The project results include an improved characterization of air emissions from equipment used in fracking, specifically for the high-power diesel frac pumps that were found to be responsible for the largest portion of emissions. The project also developed recommendations for improving the existing air emissions models for purposes of regulatory reporting and compliance, and also for potential ways to decrease air emissions from fracking operations.