The proppant in common used at present including silica sand, ceramic proppant and many kinds of composite particles that coated by resin. Compare with the silica sand, the proppant performance is much better. Because of the price is lowest, relative density is lower, and easily to pumping, so silica sand is widely used, but the strength and sphericity is lower, it will drop the conductivity of the cracks, not suit for the deep well with high closure pressures especially, using the composite particles that coated by resin, the sphericity will improve and corrosion resistance maybe reach the higher indicates, the coated resin outer can still coating the fragments even though the silica sand inner had crushing to keep the conductivity of the crack.

 It's a developing direction of ceramic proppant, but the quality guarantee period of product is too short and the cost is too high, relative density is higher than silica sand and put forward higher requirements for pumping condition and the performance of fracturing fluid using the proppant made by different material and processing technical. But the sphericity and roundness of ceramic proppant is better than silica sand, it can meet even exceed 0.9, the corrosion resistance, thermal endurance and crush resistance of ceramic proppant is far more than silica sand especially, so the conductivity of cracks will be decreasing. It's widely used in oil and gas wells now.

After fracturing, the stimulation effect and production performance of oil and gas well is depend on the conductivity of cracks, it's the ability of the reservoir fluid which conductivities by cracks, it indicated by product of the proppants' permeability and crack support width. Therefore, the type, physical properties of the proppant and the distributed in the crack are important factor that effect on the conductivity of cracks.