Numerical simulation of the environmental impact of hydraulic fracturing of tight/shale gas reservoirs on near-surface ground water: background, base cases, shallow reservoirs, short-term gas and water transport
Reagan et al. Water Resources Research. April 2015.
Summary
Researchers used the TOUGH+ geomechanics computational software and simulation system to examine gas and water transport between a deep tight gas reservoir and a shallow overlying aquifer in the two years following hydraulic fracturing operations, assuming a pre-existing connecting pathway (e.g. a fault in the formation or nearby abandoned well). This study examines separation distances of 200-800 meters between the gas reservoir and the aquifer. The research shows that such incidents of gas escape are likely to be limited in duration and scope and that the potential for brine migration tends to be downward (away from the aquifer). This work was done as part of EPA's Study of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources.