Study Nanoparticle-Stabilized CO₂ Foam for Oil Recovery at Different Pressure, Temperature, and Rock Samples

This paper presents a series of studies the nanoparticle-stabilized CO₂-foam for waterflooded residual oil recovery. Nanosilica-stabilized CO₂ foam has been observed to improve oil recovery after waterflooding in sandstone. The effects of pressure, temperature, and rock samples on the performance of CO₂ foam on residual oil recovery were investigated. The results indicated that the residual oil recovery (percent of waterflooded residual oil) by CO₂/nanosilica flooding increased from 64.9% to 75.8% when the pressure was increased from 1,200 psi to 2,500 psi. When temperature increased from 25°C to 60°C, the residual oil recovery by CO₂/nanosilica flooding decreased from 62.6% to 52.1%. The particle-stabilized CO₂ foam was also observed to improve oil recovery from limestone and dolomite after waterflooding. The results also suggested that particles plugging-in probably occurred in dolomite during the CO2 foam core flooding test.