EOR technologies such as CO2 flooding, chemical floods and WAG have been on the forefront of oil and gas R&D for the past 4 decades. While most of them are demonstrating very promising results in both lab scale and field pilots, the thrive for exploring additional EOR technologies while achieving full field application has yet to be achieved. Nano EOR is among the new frontiers that demand more improvements, therefore, new concepts and extensive innovative experimental procedures are required to identify and address key associated uncertainties.
The procedure proposed in this report includes an understanding of the Nano-EOR physical processes on lab-scale models of carbonate reservoir retrieved core plugs. (Ogolo et al., 2010). The main objectives include reducing the HSE concerns of handling and transporting the nano particles as well as targeting the unswept oil.
Carbonate core-plugs from Abu Dhabi producing oilfields with porosity ranging from 10 to 24% and permeability ranging from 77 to 149 mD were tested. Several nano particles including Fe (III) O, CuO and NiO of 50 nm range were tested after the waterflooding stage and compared for ultimate recovery factors. The nano EOR was also compared on the same cores subjected to the same conditions against chemical EOR and Electrically Enhanced Oil Recovery (EEOR). A Smart Nano-EOR process is proposed in this study that allows shifting from simultaneous to sequential Nano-EOR alongside EK.
The results obtained on our tested cores reveal that the waterflooding recovery factor ranged from 48 to 63% based on the rock properties, whereas Smart Nano-EOR revealed an ultimate recovery factor of 57 to 85% respectively. The Smart Nano-EOR process is fine tuned to reach the ultimate recovery factor when the specific mechanism is optimized based on both rock and fluid properties. Uncovering physical process enablers will be discussed in this paper to further understand the mechanisms involved in Smart-Nano-EOR.