Oil-Based Drilling Fluid Plugging Method for Strengthening Wellbore Stability of Shale Gas

Table 3

Relative content analysis of clay minerals of rock samples in the Longmaxi and Wufeng Formations.

Serial number	Well no.	Chlorite (Ch)	Illite (I)	Interlayer between Iran and Mongolia (I/S)	Interlayer ratio (%)
1	CN156	10	50	40	20
2	CN355	6	70	24	20
3	CN194	24	49	27	20
4	CN419	16	58	26	20
5	CN62	21	60	19	20
6	CN222	20	63	17	20
7	CN137	33	51	16	20