Modeling the Effect of CO2 Injection in Oil and Gas Reservoirs of Middle East To Estimate the Formation Damage and Enhanced Oil Recovery
18 Pages Posted: 24 Mar 2021
Date Written: March 24, 2021
The injection of Carbon dioxide and its performance during storage and capture activities rely on the capability of the injection well to inject the anticipated amount of CO2. Though, the CO2-rock-water interaction could cause severe formation damage by plugging the reservoir pores and reducing the permeability of a reservoir. In certain cases with the injection of CO2 oil and gas productivity and CO2 injectivity could decrease. In this study a simulator is developed to model the reactivity of injected CO2 at low and high temperature, various reservoir depths, different reservoir temperature and pressure conditions, and helps to estimate the location and magnitude of chemical reactions. Thus determines the total effect of change in reservoir porosity and permeability due to formation dissolution, transport of dissoluted particles and their deposition. The paper also presents the effect of asphaltene on the shift of relative permeability curve and related oil recovery. Moreover, we also the analysed the effect CO2 injection rate to demonstrate the effect of CO2 miscibility on oil recovery from a reservoir.
The model developed in this research is validated against the experimental data. Our results exposed that the reservoir temperature, its depth, concentration of asphaltene, rock properties have a significant effect on formation dissolution and precipitation during CO2 injection. In addition from the results with the variation in reservoir depth and temperature, we found that deep oil and gas reservoirs are good candidates for CO2 sequestration than shallow reservoirs. Because with the increase in reservoir depth, the temperature reservoir increases and this increase in temperature reduces, the dissolution rate of CO2 and lower the solid precipitation. The depiction of asphaltene with the injection of CO2 showed that asphaltene deposition reduced the oil recovery by 10 percent. Moreover, the sensitivity analysis of CO2 injection rates was performed to identify the effect of CO2 injection rate on reduced permeability in deep and high temperature formations. It was found that increased CO2 injection rates and pressures enable to reach miscibility pressure. Once this pressure is reached, there are less benefits of injecting CO2 at a higher rate for better pressure maintenance, no further diminution of residual oil. The deposition and precipitation mechanisms during CO2 injection in a reservoir vary from case to case thus the findings of cannot be generalized.
Keywords: CO2 Sequestration, Formation Damage, Oil Recovery
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