Mechanism of Surfactant Enhancement of CO₂ Displacement Recovery in Interlayer Shale Oil Reservoirs

Table 2

ODE and pore proportion in different media of rock samples.

(a) CO₂

No.	Flow volume/PV	Pore throats	Absolute ODE contribution/%	ODE/%
1	5	Small pore	14.45	84.21
		Medium pore	42.93
		Macropore	27.38
	20	Small pore	16.32	87.44
		Medium pore	43.61
		Macropore	27.51
2	5	Small pore	2.66	74.34
		Medium pore	34.44
		Macropore	37.24
	20	Small pore	8.67	89.88
		Medium pore	42.94
		Macropore	38.28
3	5	Small pore	4.77	25.15
		Medium pore	11.93
		Macropore	8.45
	20	Small pore	14.29	77.85
		Medium pore	45.16
		Macropore	18.40

(b) Surfactant + CO₂

No.	Flow volume/PV	Pore throats	Absolute ODE contribution/%	ODE/%
4	5	Small pore	16.19	85.02
		Medium pore	41.42
		Macropore	27.41
	20	Small pore	17.83	87.86
		Medium pore	42.87
		Macropore	27.16
5	5	Small pore	4.99	83.99
		Medium pore	41.47
		Macropore	37.54
	20	Small pore	10.64	91.22
		Medium pore	42.97
		Macropore	37.60
6	5	Small pore	6.70	57.81
		Medium pore	33.52
		Macropore	17.59
	20	Small pore	17.90	80.85
		Medium pore	44.43
		Macropore	18.53