摘要
CO2 sequestration in deep saline aquifers has proven to be one of the most promising options to reduce anthropogenic CO2 emissions. Sedimentary basins are chosen as targets of CO2 sequestration due to the existence of deep saline aquifers. This paper presents the first systematic investigation on the occurrence and characteristics of potential reservoirs for CO2 sequestration in deep saline aquifers in the Bohai Bay Basin (BBB) and offers detailed estimates on the storage capacity within the depth range from 800 to 3500 m. A preliminary suitability assessment for preferential sites is also presented. Geological analyses show that deep saline aquifers in Guantao formation (Ng) of Neogene, Dongying (Ed) and Shahejie formations (Es1, Es2, Es3, Es4) of Paleogene are potential reservoirs. Deep saline aquifers in the BBB may accommodate about 3922 Mt CO2 with 50 % confidence level, according to a modified CSLF (Carbon Sequestration Leadership Forum) method. The CO2 storage capacity of individual depression varies from 65 Mt (Liaohe depression) to 934 Mt (Liaodongwan-Bozhong depression). The Guantao formation (Ng) of Neogene is a regionally distributed reservoir with low TDS (Total Dissolved Solids) and favorable depth and thickness, the capacity of which accounts for 84 % of the total and is therefore considered as the most promising reservoir. Preliminary suitability assessment is carried out in terms of sedimentology, tectonic stability, geothermal conditions, saline water characteristics, potentially conflicting resources development as well as CO2 emission sources. The Liaodongwan & Bozhong, Jiyang & Changwei and Huanghua depressions are chosen as the most suitable sites for CO2 storage. Jizhong and Liaohe depressions are less suitable while Linqing depression is not suitable due to its lower tectonic stability, geological information and CO2 emission sources. Although uncertainties exist, the estimate in this study is significant for future study and implementation of CO2 sequestration in the basin.