The Effect of CO2 Adsorption on Permeability Anisotropy in the Eagle Ford Shale

Abstract

We conducted pulse-decay and steady-state flow experiments on vertically and horizontally oriented Eagle Ford Shale samples, using adsorbing gas (CO2) and non-adsorbing gas (Helium) as pore fluids. The permeability of these samples is highly anisotropic. He permeability of the Eagle Ford sample normal to bedding was ~10 nanodarcies. He permeability parallel to bedding was ~2 microdarcies. This large permeability anisotropy appears to reflect vertical flow through interconnected nanoscale pores along tortuous pathways whereas horizontal flow can also flow along microcracks and bedding planes.