High-strength and long-term durable hydrophobic polystyrene microsphere: a promising ultra-lightweight proppant for fracturing technology

Abstract

With the increasing difficulty in exploitation of low-permeability, high water content and other unconventional reservoirs, a new kind of proppants that possess not only ultra-light weight and high strength and but also hydrophobic performances have attracted more and more interests. Here, this kind of proppants were designed and prepared successfully in the form of polymer microspheres. What's more is that the polymer microspheres (named O-MSDBs) showing high strength and stable hydrophobicity were prepared by a one-step suspension polymerization between styrene, divinyl benzene and γ-methacryloxypropyl-trimethoxy silane accompanying with the formation of silica through sol–gel process. When compared with reported ultra-lightweight proppants (ULWPs), the O-MSDBs not only perform better in ultra-lightweight (0.9917 g·cm−3) and are comparable in high strength (low crushing ratio of 0.89–2.53% at 55–69 MPa), but also show new hydrophobic function. The water contact angle on the surface of O-MSDBs is 140.7° that keeps about more than 80% after mechanical abrasion or acid dissolution. The one-step facile preparation method and brilliant performances make O-MSDBs very promising to large-scale preparation and widely applied in fracturing technology as proppants.