Nanoparticle-stabilized CO2 foam to improve conventional CO2 EOR process and recovery at Batı Raman oil field, Turkey

Abstract

(B.Raman), which is the largest oil field of Turkey's already existing CO2 injection system, does not produce at the desired efficiency due to the natural fracture characteristics. Therefore, this research is performed to control the CO2 mobility in the reservoir by creating nanoparticle stabilized CO2 foam using the property of nanoparticles to be adsorbed at the gas-water interface permanently and to achieve additional oil recovery at the B. Raman oil field. In the initial stage of the research, dispersion stabilization and foamability of different nano-silicas are considered. The effects of nanoparticle concentration, salinity, temperature, and pH on foamability and dispersion stabilization were examined. Research results suggested that half hydrophobicity, salt addition, and increased concentration positively affect foamability, whereas the salinity value above 1% generated flocculation. Also, although the foam with half hydrophobic nano-silica named H30 has better foamability, this foam could not be stabilized. The effects of pressure, phase ratio, and flow rate on foam formation were also studied. The better foam was observed at the observation cell when the CO2 to Nano dispersion phase ratio was 1. It was also found that the pressure should be above 1100 psi where the CO2 was in the supercritical phase to create the foam with the current core flooding system. Then, the oil recovery test was conducted with suitable nanoparticles, particularly the PEG and CC301. Before using nano-silica particles, CO2 injection and then WAG was applied to the core sample to express the B. Raman field case. The results indicate that foam application is successful if appropriate conditions exist.