新型低密度高强度水力压裂支撑剂的研制

在油气田水力压裂中使用性能优异的低密度陶粒支撑剂，不仅可以解决支撑剂在裂缝内输送过程中的沉降问题，提高有效支撑裂缝的长度和导流能力，而且能够降低对压裂流体性能的要求，减小施工泵送功率，降低施工风险。以低品位铝矾土（A1₂O₃含量低于70%）和工业废弃物粉煤灰为主要原料，配以特殊辅料，按照一定比例混合粉磨、经制粒成球及高温煅烧等特殊工艺处理，研制出低密度高强度陶粒支撑剂，制备的粒径为0.45~0.9 mm样品体积密度为1.40~1.55 g/cm3，视密度为2.75 g/cm3左右，在52 MPa闭合压力下破碎率低于5.0%，性能优异，在低渗致密油气田和页岩气增产开发中具有广阔的应用前景。 

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.