Advancing Carbon Storage in Offshore Louisiana: Evaluation and Modeling Potential of Two Major Depleted Reservoirs in Vermilion_014 Field

In the Gulf of Mexico (GOM), current carbon capture and storage (CCS) projects have focused on the onshore parts of the GOM. However, there is growing interest in CCS in offshore GOM. At CCUS'22, the Bureau of Ocean Energy Management (BOEM) identified three depleted gas fields in the Vermilion protraction area as "Tier 1 Depleted Reservoirs" for potential CO₂ storage. Publicly available data indicates that the VR014 field has a very high capacity and seal efficiency per depleted sand reservoir. The present study assessed the potential for CO₂ storage in the two largest Vermillion 014 (VR014) depleted reservoirs: BIG2_1C (8200 ft) and CRISI2 (9800 ft). Regional and local geoscience investigations were integrated to build a detailed 3D geological model, including the depleted reservoir, seals, and intermediate wet sands, to assess the primary structural trapping mechanism of the depleted reservoirs. Further refinement was obtained by geostatistical property modeling and incorporating seismic inversion results to generate a robust property distribution. The final integrated geological model was then used for dynamic simulation of various CO₂ storage scenarios. Additionally, seismic attributes and geological analysis were undertaken to further understand the subsurface heterogeneity and refine the simulation results. The feasibility of storing in the two depleted reservoirs was evaluated through integrated subsurface interpretation and static and dynamic modeling. This research yields promising results for storing up to 155 MMT of CO₂ in the VR014 Field BIG2_1C and CRISI2 reservoirs. A substantial volume of CO₂ could be trapped in residually and structurally trapped volumes in selective regions. Solubility and mineral trapping are also taking place in lower volumes compared to the other two main trapping mechanisms with considerable amounts. Additionally, the sealing capacity of the faults and seal rocks in both reservoirs was analyzed, ensuring secure containment of the stored CO₂. The injectivity, high injection pressures, and the reservoir/seal rocks properties present challenges for CO₂ storage within Vermilion reservoirs through advanced geoscientific modeling techniques and emphasizing their potential for carbon storage; this research provides an offshore green solution for large Gulf Coast industrial emitters. The significance of this work extends to the broader understanding of CCS, providing insights into modeling, structural carbon storage, and the potential for large-scale future CCS projects in the offshore GOM.