| dc.description.abstract | Geological storage of carbon dioxide (CO2) is to inject and store a large amount of anthropogenic CO2 in deep and sealed porous rocks in order to mitigate the aggravated threat of global warning. Borehole data are used to understand the spatial distribution of suitable CO2 reservoirs and cap rocks in the Taihsi Basin, central Taiwan, where the level of seismicity is low.
Spatial distribution of formation thickness and depth for CO2 reservoirs and cap rocks indicates three CO2 storage systems existed in the study area. They are: (1) late Miocene to Pliocene Nanchuang Formation and Kueichulin Formation (reservoirs)-Chinshui Shale (cap rocks) system (hereafter abbreviated as NK-C system), (2) early to middle Miocene Shihti Formation and Peiliao Formation (reservoirs)-Talu Shale (cap rocks) system (SP-T system), (3) late Oligocene to early Miocene Wuchishan Formation and Mushan Formation (reservoirs)-Piling Shale (cap rocks) system (WM-P system).
According to distributions of depth for reservoirs and cap rocks, we assess appropriate areas for CO2 storage. Depth of reservoirs for NK-C system in the west of the study area, and depth of reservoirs for SP-T system offshore Mai-liao power plant is shallower than 800 m which are not suitable for CO2 storage. North of the study area and close to the Wu River, reservoirs for WM-P system and SP-T system reach a depth more than 3000 m, a depth too deep for storing CO2 economically. The areas mentioned foregoing are not suitable for CO2 storage, and others are applicable. However, for NK-C system, the cap rocks (i.e. the Chinshui Shale) become sand-prone due to facies changes, leading to fail to retard great amounts of CO2 underground in the south of Chang-Bin Site. There are four sites (Taichung Power Plant Site, Chang-Bin Site, Wong-gong Site and Mai-Liao Power Plant Site from north to south) considerably suitable to retard CO2 underground. Taichung Power Plant Site is suitable for NK-C system, Chang-Bin Site is suitable for SP-T system, Mai-Liao Power Plant Site is suitable for SP-T system and Wong-gong site is most prominent which can be applied to more storage system (SP-T and WM-P system). By USDOE assessment, calculated results of storage resource for CO2 show that total storage resource is about 3.54Gt, 2.71Gt and 5.82Gt for NK-C system, SP-T system and M-P system respectively. | en_US |