Effect of Brittle Mineral Size on Hydraulic Fracture Propagation in Shale Gas Reservoir

Table 1

Mixing proportions of samples with different sand sizes.

Series	Mass (kg)							28-day tensile strength (MPa)	28-day fracture toughness (MPa·m^0.5)
	Water	Cement	Clay	Sand
				2–2.36 mm	0.355–0.425 mm	0.125–0.15 mm	0.063–0.075 mm
M8	4	10	20	20				1.544	0.403
M40	4	10	20		20			1.805	0.487
M100	4	10	20			20		1.007	0.364
M200	4	10	20				20	0.961	0.227