Impact of PAM-ZnO nanocomposite on oil recovery
Centre for Sustainable Energy and Resources / School of Engineering
A new nanocomposite (NC) comprising of ZnO nanoparticles and polyacrylamide (PAM) polymer hybrid agent is investigated for enhanced oil recovery in sandstone and carbonate rocks. A range of measurements are conducted to examine the behavior of NCs including NC synthesis and characterization, NC physical properties, stability analysis, IFT, and wettability as a function of NC concentration (from 100 to 1000 ppm). Furthermore, core flood tests are performed to evaluate oil recovery and relative permeability characteristics and a numerical model is established, and history matched. The zeta potential tests verified the stability of the set NC at 200 ppm concentration in water-based solutions, while a clear reduction in IFT from 29 mN/m to 5.5 mN/m was observed at the same NC concentration. A notable shift is observed in contact angle from 133° to 13° for the sandstone rock at a 1000 ppm NC concentration suggesting a significant shift in wettability from oil-wet to strongly water-wet after NC injection while the optimal contact angle for the sandstone occurred at NC concentration of 200 ppm. Furthermore, the flooding NCs resulted in a 16.05 % increase in oil recovery factor compared to seawater flood for sandstone while a 26 % increase was recorded for carbonate sample. Likewise, the mobility ratio after NC flooding compared to seawater flooding decreased from 8.56 to 1.46. We obtained a good history match of the water cut and oil recovery factor data by creating the core dimension model. In addition, according to the fluid distribution pattern (one of the simulator outputs), the fingering phenomenon was delayed after flooding the NC compared to seawater. This study provides new insights into the impact of nanocomposite on oil recovery enhancement in sandstone and carbonate formations.