The Relationship between Current Ground Stress and Permeability of Coal in Superimposed Zones of Multistage Tectonic Movement

Table 2

The maximum and minimum principal stresses of partial CBM wells in different structural superposition zones.

Zones	Well number	Fracturing pressure (MPa)	Tensile strength (MPa)	Reservoir pressure (MPa)	Maximum principal stresses stress (MPa)	Minimum principal stresses (MPa)	Tectonic stress coefficient	Tectonic stress coefficient
I2	S-010	22.09	0.25	3.95	27.70	17.83	1.55	0.87
I2	S-011	25.78	0.28	3.85	32.09	20.48	1.53	0.88
I3	S-058	19.57	0.24	1.53	27.14	16.00	1.61	0.89
I1	S-117	21.64	0.20	7.73	23.30	17.54	1.56	0.87
I4	S-124	21.77	0.24	5.23	26.10	17.62	1.58	0.86
II4	S-005	18.33	0.50	3.85	31.99	20.38	1.36	0.71
II3	S-018	10.07	0.52	3.90	7.88	7.11	1.35	0.70
II4	S-019	14.57	0.51	3.22	13.47	10.25	1.37	0.69
II2	S-064	14.47	0.51	2.52	14.42	10.30	1.39	0.68
II1	S-085	24.82	0.49	7.62	28.47	20.14	1.38	0.68
III3	S-015	24.78	0.28	2.44	36.33	21.09	1.52	0.74
III3	S-020	22.99	0.28	2.48	37.30	20.83	1.53	0.79
III2	S-044	20.99	0.26	1.80	27.87	16.80	1.55	0.76
III2	S-062	18.48	0.25	2.10	19.06	13.13	1.52	0.77
III1	S-090	27.46	0.28	2.38	40.82	23.46	1.56	0.78
IV4	S-008	16.38	0.55	4.37	11.54	10.58	0.82	0.47
IV4	S-013	18.84	0.51	4.30	20.93	14.52	0.80	0.45
IV1	S-034	21.00	0.47	2.96	29.46	17.65	0.83	0.49
IV1	S-035	23.86	0.44	3.35	32.09	19.62	0.85	0.48
IV3	S-040	10.62	0.53	2.57	9.21	7.29	0.82	0.46
V2	S-050	18.32	0.26	2.69	13.60	11.45	0.92	0.31
V2	S-051	17.05	0.28	2.68	16.40	11.95	0.93	0.30
V1	S-060	19.11	0.30	2.78	22.84	14.81	0.90	0.32
V1	S-072	17.94	0.28	2.31	21.13	13.70	0.93	0.32
V1	S-073	19.39	0.25	7.67	20.44	15.75	0.93	0.31
VI2	S-029	24.45	0.47	2.77	27.28	18.01	1.26	0.70
VI2	S-030	24.44	0.47	3.54	29.64	19.05	1.28	0.69
VI4	S-036	21.28	0.42	4.79	29.85	18.50	1.29	0.68
VI3	S-041	23.62	0.46	3.99	29.04	18.73	1.26	0.69
VI4	S-042	13.89	0.53	2.83	16.45	10.88	1.27	0.70