Structural Characteristics and Physical Properties of Tectonically Deformed Coals
Table 4
The experiment results of gas-water phase permeability for TDCs.
Deformation series
Type of tectonically deformed coal
Coal sample’s number*
Apparent fracture porosity (%)
of CH4 (10−3μm2)
of He (10−3μm2)
(10−3μm2)
Brittle deformation
Cataclastic structure coal
HZ01
4.1
0.162
0.180
0.099
Cataclastic structure coal
QN03
1.5
0.019
0.020
0.017
Cataclastic structure coal
TY10
2.4
0.178
0.205
0.075
Mortar structure coal
TY02
2.6
0.183
0.211
0.087
Mortar structure coal
XY02
3.1
0.471
0.495
0.138
Schistose structure coal
ZJ01 (vertical sampling)
2.9
0.534
0.535
0.155
Schistose structure coal
ZJ01 (lateral sampling)
2.9
1.630
2.120
0.359
Ductile deformation
Wrinkle structure coal
BJ05
2.7
0.362
0.378
0.124
Ductile structural coal
XY06
2.0
0.089
0.098
0.056
*The direction and degree of fractures affect the drilling coal samples. We made vertical drilling in samples when there is the cross of two sets of fractures (e.g., schistose structure coal, mortar structure coal). And lateral drilling when there is only one set of fracture (Cataclastic structure coal).
**
: absolute permeability; : water phase permeability.
