A Damage Constitutive Model for the Effects of CO₂-Brine-Rock Interactions on the Brittleness of a Low-Clay Shale

Table 4

The mechanical values of shales obtained from stress-strain curves.

Condition	Soaking time (day)	Peak axial stress (MPa)	Axial strain at failure point (%)	Young’s modulus (GPa)	Axial strain (%)
					Intact	—	50.27	0.789	6.91	0.552	0.631	0.710
Subcritical CO2 + NaCl	10	40.98	0.862	5.48	0.603	0.690	0.776
	20	31.61	0.872	4.23	0.610	0.698	0.785
	30	20.57	0.943	2.48	0.660	0.754	0.849
Supercritical CO2 + NaCl	10	36.15	0.842	4.60	0.589	0.674	0.758
	20	24.50	0.993	2.89	0.695	0.794	0.894
	30	18.90	1.048	2.06	0.734	0.838	0.943