Hydraulic fracturing fluids affect water chemistry from gas wells

Travis Tasker, Penn State doctoral candidate in environmental engineering, collecting deep shale samples at a shale outcrop in Frankstown, Pennsylvania. UNIVERSITY PARK, Pa. Pressure, temperature and fluid composition play an important role in the amount of metals and other chemicals found in wastewaters from hydraulically fractured gas reservoirs, according to Penn State researchers. "We hope that this work will develop new ways for studying the processes that occur during hydraulic fracturing in a more controlled lab setting," said Travis Tasker, a doctoral candidate in environmental engineering at Penn State and principle investigator on the study. "This could also have implications for managing the wastewater that returns to the surface or understanding downhole mineral transformations that could form precipitates, clog pores and reduce a well's gas productivity." Many gas formations, such as the Marcellus shale, exist several thousand feet below the surface in higher pressure and temperature environments. Hydraulic fracturing, also known as fracking, is a common method for extracting natural gas from these formations. Fracking uses the process of injecting millions of gallons of a mixture made of sand, water and chemical additives into shale formations at high pressures.