The EOR Mechanism and Flow Behaviors of High-Viscosity Modified Starch Nanogel Particles in Porous Media

摘要

The formation of the dominant channel of water is a severe problem for most of the oilfields. Recently, gel and nanoparticles regarded as conformance water materials have attracted more attention to control water-cut and enhance oil recovery (EOR) in many water invasion reservoirs. However, nanogel particles possessing synergic properties of nanoparticles and gel are currently unavailable, which causes barrier to EOR. Here, high viscosity a-starch nanogel particles were synthesized to play the synergistic role of gel and nanoparticles economically. The average diameter of nanogel particles was 30 nm with dispersion viscosity of 250 mPa·s at 90°. Through flooding experiments, we demonstrated both light and heavy oil recovery rates reached around 30%. The nanogel particles promotes to displace oil droplets from the rock surface due the creation of the structural disjoining pressure. Also, its high viscosity properties help to drag oil clusters out of the oil phase.