Co-injection case with K_ref,x = 100 mD, (a) M_ref,x = 500, (b) M_ref,x = 1581 (or equivalently M_ref,x = 500, (a) K_ref,x = 100 mD, (b) K_ref,x = 10 mD), K_z/K_x = 0.1 and L_z = 10 m. Comparison of produced cumulative gas volume (V_g) time evolution as a function of V_DP for chemicals-free injection (“nofoam”), foam with constant M_ref,x (“ref”, dashed lines) and scaled M_ref,x (“mod”, solid lines). Relative variations are either in relation to a chemicals-free twin injection (“/ nofoam”) or a constant M_ref,x case (“/ foam”).