It is found that the low quality foams (20–30%) generated from fluid A and B possess higher apparent viscosities at shear rate below 500 s−1 and lower apparent viscosities at shear rate above 500 s−1, compared with their base fluids, as shown in Fig. 5 and Fig. 6. That is because the bubbles dispersed in the base fluid retard the development of the turbulence at the high shear rate. This is a good property for the fracturing fluid, because during fracturing a low friction loss in the tubing facility (high shear rate zone) and a high proppant suspension viscosity in the fractures (low shear rate zone) are always desired.