Investigation of Shale Permeability Evolution considering Bivalued Effective Stress Coefficients for CO₂ Injection

Figure 5

Schematic view of the pulse-decay experimental setup for the permeability evolution test. V1 is the valve controlling inlet gas flow from upstream, V2 is the valve controlling outlet gas flow to downstream, and V3/V4 is the valve controlling the confining/axial pressure applied on the sample.