CO2 storage capacity assessment of deep saline aquifers in the Subei Basin, East China

Abstract

Geological storage of carbon dioxide (CO2) is one of the most critical technologies in reducing anthropogenic and fossil fuel emissions to the atmosphere. The most critical scientific problem has been the selection of storage site for long-term safety, as well as reliable and reasonable estimation of CO2 storage capacity. This paper analyzed the stability effect factors in identifying the most suitable reservoir-seal assemblages in the Subei Basin in China. In this area, the Lower Yancheng Formation and the Upper Sanduo Formation were selected accurately based on analysis of their geomorphological and geological characteristics. Considering simultaneously the different tectonic units, cap-rock conditions, hydrodynamic conditions, and other factors, these formations could function as optimal reservoirs. The storage capacity in the aquifer layers hosted by these formations was estimated. The results showed that, on average, the storage capacity of the Lower Yancheng Formation is approximately 21.788×108t, whereas that of the Upper Sanduo Formation is approximately 45.866×108t. For the first-order tectonic units, the total storage capacity of the aforementioned two reservoir formations in the Yanfu Depression and the Dongtai Depression reaches 11.01×108 and 56.644×108t, respectively, at the basin scale.