Room 1670 Beyster Building
Speaker: Dr. Anthony Kovscek, Keleen and Carlton Beal Professor in Energy Resources Engineering, School of Earth, Energy & Environmental Sciences, Stanford University
Title: Imaging-Based Characterization of Gas Transport Through Shale As Related to Hydraulic Fracturing with CO2
The oil and gas industry has used CO2 as a hydraulic fracturing fluid and continues to evaluate applicability. Clearly, the mechanisms of gas transport (i.e., CH4, CO2, N2) through heterogeneous shale are fundamental to the success or failure of fracturing. Low-permeability, dual-porosity, gas shale (i.e., mudstone) exhibits structural and chemical features across a range of scales spanning from tens of meters to nanometers. Characterization methods and efforts for these porous media are needed to understand gas transport across scales and the interaction of gases with organic and inorganic material.
In this talk, I report progress on understanding the interplay of advective and diffusive transport in shale coupled with adsorption. X-ray computed tomography (CT) imaging of core-sized and micron-sized shale samples, as well as scanning electron microscopy (SEM), is key to developing such an understanding. Companion sorption studies show that CO2 has a strong affinity for shale surfaces that reduces the permeability of shale to CO2.