Pore-to-Core EOR Upscaling for CO2-Foam for CCUS

Abstract

An ongoing CO2-foam upscaling research project aims to advance CO2-foam technology that accelerate and increase oil recovery, with reduced operational costs and carbon footprint during CO2 EOR. Laboratory CO2-foam behavior will be upscaled to pilot scale in two onshore carbonate and sandstone reservoirs in Texas, USA. Important CO2-foam properties such as local foam generation, bubble texture, apparent viscosity and shear-thinning behavior with a nonionic surfactant were evaluated using Pore-to-Core upscaling to develop accurate numerical tools for field pilot prediction of increased sweep efficiency and CO2 utilization. On pore-scale, silicon-wafer micromodels showed in-situ foam generation and stable liquid films over time during static conditions. Intra-pore foam bubbles corroborated apparent foam viscosities measured at core-scale. CO2-foam apparent viscosity was measured at different rates (foam rate scans) and different gas fractions (foam quality scans) at core-scale. The highest mobility reduction (foam apparent viscosity) was observed between 0.60-0.70 gas fraction. The maximum foam apparent viscosity was 44.3 (±0.5) mPas, 600 times higher than that of pure CO2. The maximum apparent viscosity for the baseline (reference case, without surfactant) was 1.7 (±0.6) mPas, measured at identical conditions. CO2-foam showed shear-thinning behavior with approximately 50% reduction in apparent viscosity when the superficial velocity was increased from 1 ft/day to 8 ft/day.