Ultra-lightweight composite proppants prepared via suspension polymerization

Abstract

Polymethyl methacrylate (PMMA)/modified fly ash (MFA) composite particles have been prepared via suspension polymerization. Scanning electron microscopic results show that PMMA/MFA composite particles have perfect sphericity and roundness. Fourier transform infrared and X-ray diffraction analysis demonstrate that MFA powder is integrated with PMMA in the composites. Acid solubility tests illustrate that the particles have a good resistance to acid. In addition, apparent density of the particles (20–40 mesh) is 1.049–1.135 g/cm3 which is much lower than sand and ceramic proppants. Thermodynamic tests reveal that thermostability of the composites is significantly improved with increasing MFA addition content, which proves the particles could be used in deep underground. Furthermore, the crushing rate decreases to 3% with MFA addition content of 50% under the pressure of 69 MPa. Therefore, the composite particles manifest a promising application in shale oil or gas hydraulic fracturing as ultra-lightweight proppants.