The advent of unconventional oil and gas development has led to significant increases in the handling, management, and disposal of the liquid waste generated as part of this activity. Unsurprisingly, disposal of waste fluids generated as flowback and produced water poses significant threats to groundwater. The technology used to dispose fluid by deep-well injection has remained the same for decades and has not been updated to reflect either the significant increase in the volume of liquid waste or from improved understanding of its impact on the environment. The legacy of conventional and unconventional oil and gas development will continue into the foreseeable future. Wells and related facilities installed as part of the hydrocarbon extraction process pose potential risks to the environment and human health. The greatest risks derive from legacy wells, surface activities associated with handling and management of flowback and produced water, and disposal well construction and operation. Risks are exacerbated if less than optimal practices were used during construction and subsequent operation of legacy wells. This presentation examines how environmental threats from deep-well injection can be mitigated by improved conceptualization of both deep-well injection and the real-world response of the physical system to high-volume, long-term injection.
Ronald Green (Ph.D., P.G.) is an Institute Scientist with the Earth Science Section, Space Science and Engineering Division, at the Southwest Research Institute in San Antonio, Texas. He completed his Ph.D. degree in Hydrology at the University of Arizona in 1986.