Research Progress of Thickening Agents for Supercritical CO₂

Abstract

Although supercritical CO2fracturing has incomparable advantages compared to hydraulic fracturing as a new recreating technology of shale gas reservoir, the application of this technology has been limited by the low viscosity and weak carrying capacity of proppant. It’s critical to enhance the viscosity of supercritical CO2by adding thickening agents. Thickening agents for supercritical CO2thathave been studied by researchers mainly contained polymers, small molecular compounds and surfactants. Thickening agents that match with CO2are characterized by low cohesive energy density, low polarity, high free volume and Lewis base. It’s necessary to study the interaction between thickening agents and CO2by molecular simulation to design inexpensive, green thickening agents which could increase the viscosity of supercritical CO2remarkably under low concentration.