1, Enhance permeability of stratum Circulate oil and increase output of oil . 2, In conformity with GB/T28001-2001 Standard. 1, High strength, low breaking rate, good sphericity.2,Goog quality with reasonable price.3, Enhance permeability of stratum Circulate oil gas and increase output of oil gas.4, In conformity with GB/T28001-2001 Standard; Hydraulic fracturing sand for oilfield