Influences of Coal Properties on the Principal Permeability Tensor during Primary Coalbed Methane Recovery: A Parametric Study

Table 1

Parameters used in 18 modeling cases for evaluating how areal porosity, internal swelling ratio, and Young’s modulus influence principal permeabilities during primary CBM recovery.

Parameters		Group 1			Group 2			Group 3			Group 4			Group 5			Group 6			Reasonable value range
		Case 1	Case 2	Case 3	Case 4	Case 5	Case 6	Case 7	Case 8	Case 9	Case 10	Case 11	Case 12	Case 13	Case 14	Case 15	Case 16	Case 17	Case 18
Case-dependent parameters	(MPa)	700	700	700	700	700	700	500	1700	3000	500	1000	1500	500	1700	3000	1000	1000	1000	700-5400 [24, 25]
	(MPa)	700	700	700	700	700	700	500	1700	3000	500	1000	1500	500	1700	3000	1000	1000	1000
	(MPa)	1000	1000	1000	1000	1000	1000	500	1700	3000	1000	2000	3000	1000	1000	1000	500	1700	3000
		0.2	0.2	0.2	0.1	0.3	0.5	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.0-0.5 [3, 8]
		0.01	0.03	0.10	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.001-0.1 [24, 25]
		0.01	0.03	0.10	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01
		0.01	0.03	0.10	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01
	(mD)	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	10^-3-10^3 [5]
	(mD)	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7	0.7
	(mD)	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4
General parameters	(MPa)	5.0																		0.0-10.0 [5]
		0.3																		0.2-0.5 [24]
		0.01																		0.005-0.15 [24]
		0.01
		0.015
	(MPa)	5.0																		2.0-6.0 [24]
	(MPa)	5.0
	(MPa)	4.0