Potential prediction and storage area selection of CO₂ geological storage in deep saline aquifers in Ningxia region

Due to the concentrated carbon emission sources and the enormous carbon emissions in the Ningxia Hui Autonomous, it is necessary to evaluate carbon sequestration potential to support future CCUS planning and major demonstrations. Based on the basic geological conditions for carbon sequestration in Ningxia, this study used the volumetric method of the US Department of Energy (US-DOE) to assess the geological potential for deep saline aquifer sequestration in Ningxia. The results show that the predicted geological potential of carbon sequestration in the deep saline aquifers in Ningxia is approximately 86.742 billion tons, with the predicted technical capacity of about 42.334 billion tons. The main reservoirs are concentrated in the Yanchi area in eastern Ningxia and the Liupan Mountain Basin. A preliminary evaluation of the suitability of saline aquifer sequestration in Ningxia was conducted by considering many factors such as the overall sequestration potential, cap rock integrity, geological stability, and socio-environmental risks. The results indicate that the Yanchi area in eastern Ningxia has favorable reservoir and cap rock conditions, stable structures, and low population density, making it a potential region for CO₂ sequestration in Ningxia.