Table 3.

Calculation results of the forced imbibition oil recovery achieved using different surfactants.

Core number	Core saturated water			Core saturated oil				Evaluation of imbibition efficiency
	m3/g	m4/g	W1/g	V1/mL	W2/g	W3/g	W4/g	W5/g	V2/mL	Imbibition recovery/%
L-1	77.1862	81.8124	4.6263	3.1463	1.4800	81.3253	2.6592	81.6458	2.0702	65.80
L-2	76.7850	81.3342	4.5492	2.8842	1.6650	80.7145	2.2645	80.8834	0.7861	27.26
L-3	77.0346	81.7912	4.7567	3.0014	1.7553	81.1338	2.3440	81.4071	1.2478	41.57
L-4	77.8915	82.4342	4.5427	3.9842	0.5585	81.8145	3.3645	82.0534	1.5359	38.55