Self-emulsifying water shutoff agent based on fumed silica nanoparticles for high temperature horizontal gas wells

Abstract

Excessive water production by high temperature (>140 °C) horizontal gas wells sharply decreases productivity. To date, no effective water shutoff agent has been developed to address this problem. In this study, a nanoparticle-reinforced active oil system that can be spontaneously emulsified under Tahe Formation conditions was constructed. The nanoparticles enhanced the water shutoff performance of the system by migrating to the oil-water interface and attaching to the formation surface; this decreased the water permeability to 6.25% of the pure active oil water shutoff under conditions of gas reservoir formation, thus achieving better efficacy and selectivity.