鄂尔多斯盆地咸水层CO2封存地质体筛选与封存能力评估OA

For purposes of target screening and capacity evaluation of CO2 storage in saline aquifers of the Ordos Basin,the carbon capture and storage(CCS)technologies and practices at home and abroad were investigated.On this basis,the characteristics of the saline aquifers were analyzed,the siting principles for the CO2 storage were determined,and thus the vertical target horizons and lateral target areas were selected.Furthermore,based on the mechanism of CO2 storage in saline aquifers,a method for calculating the effective storage capacity was established.Finally,the storage capacity of the saline aquifers was assessed through numerical simulation.The following results are obtained.(i)Taking into account various factors such as reservoir conditions,geological stability,hydrogeological conditions,and source-reservoir relationships comprehensively,it is recommended to select the Lower Triassic Liujiagou Formation and Upper Permian Shiqianfeng Formation as the major horizons for CO2 storage,with priority given to the 1 000 km2 region around the major industrial parks(carbon sources)especially in the Yushen and Yuheng mining areas in Shaanxi province and the Nalinhe mining area in Inner Mongolia in the eastern basin as alternatives for CO2 storage.(ii)Regarding the situations without water production wells for draining formation water,a CO2 storage capacity calculation method is established considering displacement effect,dissolution effect and binding effect respectively.Using this method,together with numerical simulation technology,the effective CO2 storage capacity of the 1 000 km2 saline aquifer in the Liujiagou Formation is determined to be 0.59×108 t,and the initial CO2 injection productivity of the storage facility is predicted to be 10×104 m3/d by numerical simulation.It is concluded that the proposed CO2 storage siting principles and capacity calculation method provide a basis for assessing the feasibility and prospects of CO2 storage in saline aquifers of the basin,and can also serve as a reference for CCS in saline aquifers in other domestic areas.