Experimental Investigation on Cyclic Huff-n-Puff with Surfactants Based on Complex Fracture Networks in Water-Wet Oil Reservoirs with Extralow Permeability

Table 2

Oil recovery for each experiment at different threshold injection pressure.

Sample	Gas permeability (×10^-3μm^2)	Oil saturation (%)	Threshold injection pressure (MPa)	Soaking time (hour)	Oil recovery (%)
Core 1^#	5.2	60.28	5	24	38.6
Core 2^#	4.9	60.35	10	24	42.2
Core 3^#	5.1	60.37	20	24	45.1