Analysis and Calculation of Threshold Pressure Gradient Based on Capillary Bundle

Table 4

The seepage equation fitting parameters for various permeability cores.

Gas logging permeability × 10^−3 μm^2	Low flow, <1.728 m/d			High flow, >1.728 m/d
	a	b	c	a2	b2	c2
1.97	4401173	41495.94	0.270135	270974.2	29381.52	11.54866
2.39	965176.1	23992.24	0.550795	299825.1	19745.3	6.815821
3.45	2483235	20298.96	0.447727	106402.5	11171.91	11.77325
8.93	690991.8	3742.243	0.12773	224498.1	3066.88	0.328465
9.96	2120510	6538.008	0.078849	229873.3	3800.372	0.873352
11.81	639844.8	6462.558	0.055449	205292.8	5856.899	0.220347
14.96	546029.8	2904.804	0.125703	23705.57	1948.148	0.811546
26.1	133718.5	1105.043	0.065861	0	775.07	0.2131
28.91	416471.6	1405.897	0.035546	0	680.41	0.2896
31.07	822100.9	2226.526	0.131521	6839.687	757.4748	1.009064
Fitting result	4E + 06k^−0.724	79472k^−1.176	0.6633k^−0.722	4E + 6k^−1.034	68163x^−1.309	21.622x^−1.317