Wellbore Stability in Oil and Gas Drilling with Chemical-Mechanical Coupling

Table 2

Experiment results of cores immersing in drilling fluid.

Immersing time (h)	0	2	6	12	24	48	96	192
Water content increment Δ𝐶𝑆 (%)	0	0.82	2.03	2.70	3.28	4.46	5.11	5.68
UCS (MPa)	16.30	13.56	11.76	12.24	9.48	8.28	8.52	6.60
Poisson's ratio	0.26	0.30	0.32	0.30	0.34	0.38	0.41	0.40
Elastic modulus (MPa)	5518.37	4055.17	2881.29	2176.90	2111.45	1759.96	2165.25	1599.73