Carbon capture and sequestration technologies have been developed to limit the release of carbon dioxide into the atmosphere as a result of their global warming potential. One of the major ways for carbon sequestration is the use of a CO2 geological storage, and several countries have keyed into the use of these technology.
Previous researches have applied numerical simulations for the effective study of CO2 geological storage technologies. They discovered that those associated with sloping reservoir indicates the dip angle and injection pressure as the major effect on the CO2 injection amount. However, investigations with layered sloping reservoir having low porosity and permeability have not been carried out extensively.
Dr. Fugang Wang and colleagues at Jilin University in China developed a three dimensional numerical model to investigate the impact of injection pressure and dip angle on the CO2 injection amount in a layered sloping reservoir. The authors considered one of the reservoir functions of the Ordos carbon dioxide capture and geological storage demonstration project in China. The research work is now published in Greenhouse gases Science and Technology,
For the numerical simulation design, the authors considered four types of injection pressure which included 1.2, 1.3, 1.4 and 1.5 times of the strata hydrostatic pressure, four different dip angle of strata (0[Symbol], 5[Symbol], 10[Symbol] and 15[Symbol]), injection time of 30 years for the 1.2 times of strata hydrostatic pressure and the remaining for 20 years, and parameters such as thickness, porosity, permeability and temperature were provided on site of the actual monitoring data.
The authors when comparing the sloping reservoir to that of the horizontal which considered no effects of dip angle noticed that the CO2 injection amount was the same for both at the ‘balance time point’.
They also discovered that the effect of dip angle on the total CO2 injection amount varies as increase in dip angle for a particular injection pressure led to an increase in CO2 injection amount before the balance time point when observed for the sloping reservoir but reverse was the case after the balance time point.
The injection pressure also had a say on the maximum value of CO2 injection amount as an increase in the former led to a decrease in the latter when observed before the balance time point but the dip angles had no effect on the maximum value.
The numerical simulation model further showed that an asymmetric pressure distribution occurred in the sloping reservoirs but symmetric pressure occurred in horizontal reservoirs. This influenced the effects of the injection pressure and the total CO2 injection amount.
Results from the saturation of supercritical carbon dioxide distribution for one of the reservoir formations of the Ordos CCS demonstration project with low porosity and permeability indicated that the injection pressure had a major impact on the CO2 injection amount which wasn’t the case for the tested dip angles when injection periods were lesser than 20 years.
Further numerical simulation result showed that sloping reservoirs with smaller dip angle is advantageous for effective storage of carbon dioxide. The research team provided profound investigations on CO2 geological storage facility, having low porosity and permeability with effects of dip angle and injection pressure.
Wang, F., Jing, J., Yang, Y., Liu, H., Sun, Z., Xu, T., Tian, H. Impacts of Injection Pressure of a Dip-Angle Sloping Strata reservoir with low porosity and permeability on CO2 injection amount, Greenhouse Gases Science and Technology 7 (2017) 92-105.Go To Greenhouse Gases Science and Technology
Fugang Wang, Jing Jing, Tianfu Xu, Yanlin Yang, Guangrong Jin. Impacts of stratum dip angle on CO2 geological storage amount and security. Greenhouse Gases: Science and Technology, 6:1–13 (2016)Go To Greenhouse Gases Science and Technology