... proppant is the key material in low-permeability fracturing of oil and gas wells exploration. This products used in the ... in the cracks, fracturing close to the high oil recovery operations, so that oil and gas cracked rock, support for propping fractures ... (105KN), 69Mpa (140KN), and 86Mpa, (174KN) three series, according to bulk density are divided into: low-density, medium density, high-density ...