Researchers in India are using multi-wall carbon nanotube-optimized surfactant-polymer flooding for enhanced oil recovery. In an open-access paper in the journal Fuel, they report that their experimental application of carbon nanotube-based fluids yielded an oil recovery factor of approximately 70% of the original oil in place.

Pandey et al.

Primary oil recovery extracts oil using natural or artificial lift devices, bringing hydrocarbons to the surface. The primary methods have limitations in exploiting oil, as they focus on pay zones with good oil saturation. The conventional recovery method can only extract about 30 % of the oil reserves. Various enhanced oil recovery (EOR) approaches aid in recovering the remaining oil after primary methods. The EOR procedures comprise thermal recovery, gas injection, and chemical injection.

… In the present study, a modified multi-wall carbon nanotube (mMWCNT) solution was subjected to surface/interfacial forces, contact angle, and loss of surfactant studies. The impact of carbon nanotubes (mMWCNTs) on an SP solution’s ST/IFT and wettability is studied using surface tensiometer and contact angle experiments. These tests establish the CMC [critical micelle concentration] of the surfactant and conclude the optimal concentration of mMWCNT for improving oil recovery. The influence of the mMWCNT concentrations on the reduction of surfactant loss on the sandstone surface in the SP solution was examined at various concentrations. Reviewing prior studies on the application of NPs in SP flooding reveals that the impact of mMWCNT is yet to be studied, implying that no research reports the effect of mMWCNT on SP solution.

—Pandey et al.

The researchers found that the modified multi-wall carbon nanotubes significantly reduced surface and interfacial tension by approximately 59% and 56%, respectively, at the optimum concentration.

The nanotubes also successfully minimized surfactant loss by about 49.3%. The contact angle experiments demonstrated that the modified nanotubes transformed the rock surface from oil-wet to water-wet, as evidenced by a substantial reduction of approximately 54% in the contact angle value.

The core flooding experiment, employing a chemical slug composed of SDS at CMC, modified multi-wall carbon nanotubes, and industrial-grade polymer, yielded an oil recovery factor of approximately 70% of the original oil in place.

Resources

• Anurag Pandey, Syed Feraz Qamar, Sumanta Das, Surita Basu, Himanshu Kesarwani, Amit Saxena, Shivanjali Sharma, Jayati Sarkar (2023) “Advanced multi-wall carbon nanotube-optimized surfactant-polymer flooding for enhanced oil recovery,” Fuel, Volume 355, doi: 10.1016/j.fuel.2023.129463