Development of a New Low Density High Strength Hydraulic Fracturing Proppant

The use of high performance low density ceramic proppants in reservoir fracturing not only avoids the settling of proppant particles during their migration in fractures, thereby effectively lengthening the fracturespropped and enhancing the fluid conductivity of the fractures, it also helps relax the requirements for the performance of fracturing fluid, and reduce the pumping power required and minimize operating risks. This paper discusses the preparation of a low density high strength ceramic proppant from a low-grade bauxite (containing less than A1₂O₃) and fly ash, an industrial waste. Mixtures of the bauxite, the fly ash and some special accessories in a certain ratio were ground, and then calcined at high temperatures to form spherical ceramic particles with low density and high strength. The proppant prepared had particle sizes between 0.45 mm and 0.9 mm, bulk density between 1.40 g/cm³ and 1.55 g/cm³, and apparent density of ca. 2.75 g/cm³. In laboratory test, only 5% of the proppant particles were broken into pieces under a closure pressure of 52 MPa. This ceramic proppant, because of its superior performance, will find wide application in low permeability reservoir development and shale gas reservoir stimulation.