Modelling of Time-Dependent Wellbore Collapse in Hard Brittle Shale Formation under Underbalanced Drilling Condition

Table 2

Relative content of clay minerals.

Well	Relative content (%)					Interlayer ratio (%)
	Illite (I)	Montmorillonite (S)	Illite/montmorillonite (I/S)	Kaolinite (K)	Chlorite (C)
W-81	49.78	0.00	12.63	6.27	31.33	15.00
W-82	56.54	0.00	6.72	0.00	36.74	10.00
W-96	34.47	0.00	39.74	10.62	15.17	25.00