Fig. 2

Sample strain (axial) versus differential stress (σ_diff) curves for Bentheim sandstone samples, obtained at different confining pressures (P_c). Legend is the same for all three panels and shown in panel c. To improve readability, the repeat experiments (performed at 10 MPa) are assigned a purple colour instead of yellow. Stress–strain curves are not influenced by fluid type. a sandstone with water; b sandstone with inhibitor 1 (3000 ppm); c sandstone with inhibitor 2 (3000 ppm)