The Drainage Horizon Determination of High Directional Long Borehole and Gas Control Effect Analysis

Table 1

The mechanical parameters of major rock mass for roof and floor.

Name of rock	Density (kg·m^−3)	Bulk modulus (GPa)	Shear modulus (GPa)	Cohesion (MPa)	Angle of internal friction (°)	Tensile strength (MPa)
Sandstone	2600	5.27	11	2.3	39	4.35
Fine sandstone	2645	4.62	18	8.36	34	2.35
Siltstone	2700	5.6	7	5.3	35	2.86
Mudstone	2550	4.16	4.69	1.41	37	3.2
Coal seam 8#	1350	3.95	2.2	2	30	1.04
Siltstone	2700	5.6	3.8	5.3	35	2.86
Limestone	2540	6.85	1.47	1.26	10	1.2
Silty mudstone	2132	6	8.13	8.87	42	4.56
Limestone	2540	6.85	1.47	1.26	10	1.2
Silty mudstone	2132	6	8.13	8.87	42	4.56
Coal seam 9#	1300	4.33	5.1	2	38	1.04
Fine sandstone	2245	24.62	12	6.36	34	2.35
Siltstone	2100	5.6	7	5.3	35	2.86
Coal seam 10#	1350	3.95	2.2	2	30	1.04
Medium sandstone	2132	26	8.13	11.87	42	4.56