Polymer microspheres: Influence of composition and porosity on filtrate reduction from aqueous fluids

ABSTRACT During the drilling and completion of oil wells, the drilling fluid flowing down the annulus can invade the rock formation, possibly causing irreversible damage to the reservoir. One of the main functions of these fluids is to form a film with low permeability on the borehole wall to prevent invasion of filtrate in the rock formation. Polymeric additives are increasingly used to control these infiltrations. Recent studies have shown the potential of using microspheres made of poly(methyl methacrylate‐co‐vinyl acetate) (PMMA‐co‐PVAc) with dimensions compatible with the size of the formation pores. In this study, PMMA and PMMA‐co‐PVAc polymers were synthesized by suspension polymerization, producing in the presence or absence of porogenic agents. The particles porosities influence the glass transition temperature, surface roughness and apparent density. The results also demonstrate that less rigid spheres with pores in their structure form a more efficient barrier against filtration to the rock formation. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44484.