Experimental Study on the Damage of Artificial Fracture Permeability in Coal during the Flow Back of Guar-Based Fracturing Fluid

Figure 7

Residues of HPG fracturing fluid with different concentrations in ceramic proppant pack. (a) 0.1% HPG. (b) 0.2% HPG. (c) 0.3% HPG. (d) 0.4% HPG.

(a)

(b)

(c)

(d)