DEM-CFD Modeling of Proppant Pillar Deformation and Stability during the Fracturing Fluid Flowback

Table 2

Summary of microscale properties of proppant.

Proppant size combination			40/70	30/50	20/40
Microparameters	Linear contacts	Apparent modulus Ec (MPa)	100
		Normal stiffness kn (N/m)	2DEc
		Shear stiffness ks (N/m)	k n
	Parallel bonds	Apparent modulus Ec (MPa)	100
		Normal stiffness kn (MPa/m)	E c/D
		Shear stiffness ks (MPa/m)	k n
		Normal bond strength (Pa)	3000
		Shear bond strength (Pa)	3000
		Radius multiplier	1
	Friction		0.9
	Density (kg/m^3)		2650
	Particle radius (D/2) (mm)		0.21–0.42	0.3–0.6	0.42–0.84