Nanoscale Pore Structure Characterization and Permeability of Mudrocks and Fine-Grained Sandstones in Coal Reservoirs by Scanning Electron Microscopy, Mercury Intrusion Porosimetry, and Low-Field Nuclear Magnetic Resonance

Table 3

Density, permeability, and porosities of the investigated rock samples.

Sample number	Density (g/cm^3)	Permeability () (mD)	He porosity () (%)	MIP porosity   (%)	Water porosity () (%)	NMR porosity () (%)	Statistical parameters of porosity
							Average () (%)	Standard deviation (SD) (%)	Relative SD (%)
JH-Y	2.53	0.0003	1.40	1.86	1.70	2.15	1.78	0.31	17.52
JH-S	2.57	0.0046	3.70	2.92	3.31	3.50	3.36	0.33	9.88
NT-Y1	2.64	0.0006	6.30	6.16	5.89	6.13	6.12	0.17	2.78
NT-Y2	2.36	0.0015	8.20	8.38	9.16	9.53	8.82	0.63	7.16
NT-Y3	2.51	0.0028	13.40	7.58	12.67	12.84	11.62	2.71	23.33
NT-M1	2.44	0.0018	4.70	7.05	9.15	9.40	7.57	2.19	28.88
NT-M2	2.46	0.0048	5.80	8.06	10.70	10.71	8.82	2.37	26.85
NT-M3	2.40	0.0008	6.40	10.26	11.18	11.73	9.89	2.41	24.32
NT-M4	2.40	0.0017	7.70	7.30	10.01	10.45	8.87	1.60	18.01
NT-M5	2.40	0.0012	8.30	8.05	10.25	10.67	9.32	1.33	14.31
NT-M6	2.37	0.0026	10.20	8.68	10.21	10.90	10.00	0.94	9.38
NT-S	2.17	2.4133	17.50	15.26	16.59	16.63	16.50	0.92	5.60