A hybrid nanocomposite of poly(styrene-methyl methacrylate- acrylic acid) /clay as a novel rheology-improvement additive for drilling fluids

The hybrid-polymer nanocomposite poly(styrene-methyl methacrylate- acrylic acid) /nanoclay was synthesized by miniemulsion polymerization for novel use as a drilling fluid additive. Three low-solid-drilling fluids (bentonite-based; natural polymer-based; nanoclay-based) were formulated using the hybrid nanocomposite as an additive and their rheological performance compared. The polymer/clay hybrid nanoparticles significantly improve rheological and filtration properties of the drilling fluids and they remain stable at high pressure, high temperature and harsh salinity conditions. The fluids' filtration properties improve as the concentration of the polymer/nanoclay-hybrid-nanoparticles increases. The clay-based nanocomposite additive had the highest positive impact on the rheological behavior of low-solids polymer-based drilling fluid. Analysis of rheological properties and filtration loss of the drilling fluids suggest that the optimum nanoclay concentration in the hybrid-polymer nanocomposite is about 5wt.%.