A Modeling Study of Air Migration from a Drilling Well to the Surrounding Aquifer in Appalachia

We investigate the migration of high pressure air in a fractured groundwater aquifer during the process of drilling a shale gas well using the air hammer technique. We consider a scenario where the high pressure air used for the drilling process could leak into the aquifer. A three-dimensional conceptual numerical model was developed using TOUGH2 to quantify the spatial and temporal impact of such a leak on the surrounding aquifers. We have also studied the sensitivity of the numerical model to the air pressure used during the drilling process. Our simulations indicate that the air migrated through the fractures and was released approximately 300 m away from leaking area in just a few hours.