Study on Micro Displacement Mechanism of Hydraulic Fracturing by Oil Displacement Agent at High Pressure

Table 1

The wettability grading standards.

Wettability index	Wettability grade
	Oil-wet	Weak oil-wet	Neutral	Weak water-wet	Water-wet
The wettability index of oil phase	1~0.8	0.7~0.6	Approximate	0.3~0.4	0~0.2
The wettability index of water phase	0~0.2	0.3~0.4		0.7~0.6	1~0.8
	[-1,-0.1]		(-0.1,0.1)	(0.1,1]