Experimental Study of Fracturing Fluid Retention in Rough Fractures

Table 1

Classification criteria of fractures.

Type	Aperture	Characteristic	Connectivity
Primary fracture	>0.80 mm	Single, large aperture, main flow channel	Excellent conductivity
Secondary fracture	0.25–0.80 mm	Large number, small aperture	Good connectivity with primary fracture
Microcrack	<0.25 mm	Discrete distribution, small scale	Poor connectivity