Well Placement Strategy on Carbon Dioxide Storage in Saline Aquifer at Mae Moh Basin

The need for urgent climate action and achieving net-zero emissions drives the development of CCS technologies, including CO₂ injection and storage in saline aquifers. This aligns perfectly with Thailand's ambitious commitment to combat climate change and achieve net-zero emissions, reflecting the global imperative for efficient CCS initiatives. Geologically unique formations like the Mae Moh basin in Thailand offer significant potential for carbon storage because it’s a coal-fired power plant is located nearby which releases about 10 Mtpa, making them pivotal players in supporting Thailand's net-zero target. The current study focuses on an examination of well placement strategies, a crucial element in optimizing CO₂ storage efficiency within saline aquifers. By targeting the geological context of Mae Moh basin, we investigated and compared the performance of four distinct well-pattern scenarios: Single Vertical Injection (SVI), Single Horizontal Injection (SHI), Two Vertical Injection (TVI), and Two Vertical Injection and Brine Production (TVIP) wells. Each of these scenarios serves as an indicator of well-placement efficiency tailored to the specific geological intricacies of Mae Moh basin. Over a 30-year period of injection, the TVI is remarkably the most effective configuration, injecting as much as 1.70 MtCO₂, which is attributed to the presence of two vertical injection wells that facilitating efficient and rapid CO₂ co-injection. The TVIP introduces an innovative approach by combining CO₂ injection with brine production, resulting in a cumulative injection of approximately 0.86 MtCO₂. Additionally, the analysis of CO₂ trapping mechanisms reveals a dynamic interplay, of which structural and residual gas trapping mechanisms dominate the early stage of injection before transitions to solubility trapping over time. The current investigation emphasizes the adaptability required for CCS project operating in challenging geological conditions.