CO2 Sequestrated EOR

1. Upon exceeding MMP, CO2 & Oil would become completely miscible and eventually, the associated IFT would be down to zero. If so, are we determining the IFT between brine and CO2-Oil mixture in CO2 sequestrated EOR technique?

2. Whether IFT would always keep decreasing, when the mole fraction of CO2 in mixture keeps increasing?

3. How sensitive the IFT between brine and oil, given the varying solubility of CO2 in crude-oil and brine?

4. To what extent, the accumulation of aromatic molecules in light oil @ oil-brine interface (attributed to the weak hydrogen bond interaction between brine & aromatic hydrocarbon); and the assemblage of the asphaltene molecules @ oil-brine interface (resulting from nano-aggregation to thin-film formation) would have an influence over the resulting interfacial properties in CO2 sequestrated EOR technique?

5. Why do CO2 molecules display hydrophilicity and intermingle narrowly with brine molecules @ interface?

6. If two interfaces associated with an oil-brine-CO2 system remain at an angle to z-axis (not normal) and if they remain at an angle to xy-plane (not parallel), then, would it remain feasible to estimate Gibbs interfacial tension as a function of traditional pressure tensor?

7. Upon injecting scCO2, how long scCO2 molecules are expected to remain to be miscible with oil, where eventually, scCO2 molecules start accumulating within the brine-oil interface?

Upon continuous injection of scCO2 molecules, would it tend to rotate oil molecules from parallel to normal to the interface by enhancing the interfacial roughness?

Whether the driving force of CO2 accumulation results only from the difference of the IFT between oil and brine; and that between CO2 and brine?

8. Feasible to enhance the interaction between brine and CO2; and that between CO2 and oil, while also ensuring that the difference between the above two interactions remain to be insignificant so that the injected CO2 would remain to be favorable towards mitigating the IFT between oil and brine?

9. Doe scCO2 aid in improving oil-brine mobility ratio, which in turn, would enhance the sweep efficiency of brine?

Suresh Kumar Govindarajan

Professor (HAG)

IIT Madras

01-Sep-2024