Application of numerical simulation to pilot project of CO2 geological sequestration

The geological sequestration of CO2 in deep saline aquifer is an effective countermeasure for reducing global warming and greenhouse effect. Based on the Shenhua Ordos CO2 capture and storage (CCS) pilot project, the behavior of CO2 in deep saline aquifers is investigated. The transport process of CO2 fluid, the pressure buildup of system and the reserves potential of sequestration are analyzed. This model can provide technological support and save human and financial resources for Shenhua CCS engineering project. First, the model is calibrated by comparing simulated results and measured pressure values. The suitable pressure curve is obtained and the main hydrological parameters are determined at this stage. Then an assumption of CO2 continuing injection for 3 years is simulated based on the former model. The CO2 diffusion, solution behavior, pressure variation and total reserves of strata are analyzed. The conclusions are drawn as follows: the largest distance of CO2 migration is about 350 m; hydraulic fracturing can improve CO2 injectivity obviously; cap rock can effectively prevent the escape of CO2. Simulation results demonstrate that even though the deep saline aquifers of Ordos basin has low penetrability, it is also suitable for CO2 sequestration.