應對氣候變化的緊迫性因全球碳排放問題而更加凸顯，而在鹽水層中進行二氧化碳地質封存（CO₂ geo-sequestration）已成為碳捕集與封存（CCS）的一項關鍵策略。然而，許多研究尚未充分探討二氧化碳和鹽水密度的作用，以及二氧化碳密度與蓋層滲透率變化對儲存性能的影響。此外，洩漏風險仍然是一項重大挑戰，需要準確的預測以確保儲存場址的安全性和有效性。本研究利用由國立中央大學（NCU）CAMRDA開發的THMC模型，模擬地下熱-水-力-化（T-H-M-C）過程之間的複雜相互作用。該模型專注於模擬二氧化碳在不同密度和蓋層滲透率條件下的運移與穩定性，同時評估二氧化碳沿蓋層斷層洩漏的可能性。研究結果表明，二氧化碳密度顯著影響羽流行為：低密度二氧化碳因浮力效應迅速上升至含水層頂部，增加洩漏風險；而高密度二氧化碳則表現出更穩定的行為，垂直運移減少。此外，研究結果證實，THMC模型能夠有效模擬深鹽水層中的二氧化碳儲存，識別潛在洩漏路徑，並為提升注入一年期間的儲存系統安全性與穩定性提供有價值的見解。;The urgency of addressing climate change is underscored by the global carbon issue, highlighting CO₂ geo-sequestration within saline aquifers as a key strategy for carbon capture and storage (CCS). However, many studies have yet to fully explore the roles of CO₂ and brine densities, as well as the effects of CO₂ density and caprock permeability variations on storage performance. Additionally, leakage risk remains a significant challenge, necessitating accurate predictions to ensure storage site safety and effectiveness. This study utilizes the THMC model, developed by CAMRDA at NCU, to simulate the complex interplay of underground thermo-hydro-mechanical-chemical (T-H-M-C) processes. The model focuses on the movement and stabilization of CO₂ under varying density and caprock permeability conditions, while also assessing the potential for CO₂ leakage along faults in the caprock layer. The findings indicate that CO₂ density significantly influences plume behavior: low-density CO₂ tends to rise rapidly toward the top of the aquifer due to buoyancy, increasing leakage risks. At the same time, high-density CO₂ exhibits more stable behavior with reduced vertical migration. Moreover, the results demonstrate that the THMC model effectively simulates CO₂ storage in deep saline aquifers, identifying potential leakage pathways and providing insights to improve storage system safety and stability during a year of injection
