Pore Structure and Limit Pressure of Gas Slippage Effect in Tight Sandstone

Table 2

Basic parameters of core samples.

Samples	𝐾𝑎 (10^−3𝜇m^2)	Φ (%)	𝑅35 (𝜇m)	𝑝𝑑 (MPa)	𝑝limit (MPa)	Relationships between 1/𝑝𝑚 and 𝐾𝑎 for samples	𝑏	𝐾𝑎 range (%)
SS-1	0.05	15.130	0.023	1.8	1.42	𝑦=0.0001𝑥+0.0032=0.0032(1+0.031𝑥)	0.031	1.83
SS-2	0.074	6.689	0.226	2.38	0.9	𝑦=0.0002𝑥+0.0231=0.0231(1+0.008𝑥)	0.008	0.62
SS-3	0.150	5.895	0.382	2.15	0.6	𝑦=0.0004𝑥+0.0382=0.0382(1+0.010𝑥)	0.010	0.64
SS-4	0.226	1.106	2.061	1.47	0.5	𝑦=0.0006𝑥+0.0771=0.0771(1+0.008𝑥)	0.008	0.60
SS-5	0.507	5.647	0.811	0.912	0.45	𝑦=0.0007𝑥+0.1534=0.1534(1+0.005𝑥)	0.005	2.50
SS-6	1.090	10.099	0.769	0.85	0.4	𝑦=0.0019𝑥+0.4162=0.4162(1+0.005𝑥)	0.005	0.45
SS-7	1.320	12.461	0.718	0.62	0.35	𝑦=0.0108𝑥+0.7911=0.7911(1+0.013𝑥)	0.013	2.06

𝑅₃₅: mean pore throat radius; 𝑝_𝑑: displacement pressure; 𝑝_limit: limit pressure.