Permeability Characterization and Its Correlation with Pore Microstructure of Stress-Sensitive Tight Sandstone: Take Chang 6 in Ordos Basin for Example

Table 4

Different net stress change modes and their correspondence with actual working conditions.

Modes		Net stress/MPa	Corresponding working conditions
Loading method	Variable confining pressure	2.5-5-8-11-15-20-30-20-15-11-8-5-2.5	Overburden pressure change
	Variable flow pressure	2.5-5-8-11-15-20-30-20-15-11-8-5-2.5	Reservoir fluid-producing
Cyclic loading		2.5-5-8-11-15-20-30-20-15-11-8-5-2.5-5-8-11-15-20-30-20-15-11-8-5-2.5	Energy supplement-production process
Loading rate		2.5-5-7.5-10-12.5-15-17.5-20-30	Different oil production rate
		2.5-5-10-15-20-30
		2.5-10-20-30