Evaluation of carbon dioxide storage in the deep saline layer of the Ordovician Majiagou Formation in the Ordos Basin

Abstract

Abstract Geologic CO2 storage (GCS) is one of the preferred solutions to reduce greenhouse gas emissions. Comparing with other geological reservoirs, the deep saline aquifers have huge storage potential and currently the most promising one. Since technical and economical viability of geologic CO2 storage depends highly on the CO2 storage capacity, this paper mainly uses the storage mechanism method to estimate the CO2 storage capacity of the Ordovician Majiagou Formation in order to give data support for GCS project in the Ordos Basin. The results show that the total effective CO2 storage capacity of the deep brine layer of the Ordovician Majiagou Formation in the Ordos Basin is 15.98-109.22Gt. The Majiagou Formation has sufficient storage capacity to accommodate decades of CO2 emissions generated by multiple coal-fired power plants in the Ordos Basin. For CO2 geological storage, the structural trapping mechanism contributes the largest amount of CO2 storage, and the amount of CO2 storage contributed by the two mechanisms of bound gas trapping and solubility trapping is almost negligible. The above results provide methods and references for CO2 estimation of GCS project in this region, and provide data support for the site selection and injection of CO2 sequestration in deep salt layers of the Ordos Basin.