Dynamic modeling of geological carbon storage in aquifers – workflows and practices

• Published in: International journal of greenhouse gas control 2024-10, Vol.138, p.104235, Article 104235
• Main Authors: Hosseini, Seyyed A., Ershadnia, Reza, Lun, Lisa, Morgan, Stephen, Bennett, Matthew, Skrivanos, Chris, Li, Boxiao, Soltanian, Mohamad Reza, Pawar, Rajesh, Hovorka, Susan D.
• Format: Article
• Language: English
• Subjects: Class VI permit; Geological storage; Modeling; Numerical simulation; Workflows
• ISSN: 1750-5836
• DOI: 10.1016/j.ijggc.2024.104235

•Simplified equation solutions have greatly enhanced our understanding of the GCS systems but numerical simulation are needed for real field applications and regulatory requirements.•It is crucial to have a well-defined structural framework that accurately characterizes horizons, faults, and geological features, such as geometry, dip, spill points, and properties of the surrounding layers. Grid resolution should match the size of geological features controlling CO2 plume behavior.•Need to develop geochemical and geomechanical models depends on the project needs, and initial simple studies to identify the related risks. Geological carbon storage (GCS), particularly within deep saline aquifers, is considered a promising and efficient approach for sequestering significant volumes of anthropogenic CO2. Computational models play a crucial role in assessing the feasibility of GCS, as they contribute to risk assessment, delineation of area of review, short-term and long-term monitoring design, regulatory compliance, decision-making, project planning and optimization. Currently, there are numerous applications for Class VI permits with accompanied GCS modeling results with various levels of implementation of best practices that the industry and academia has developed over the past several years. It is, therefore, necessary to document the established practices, with the aim of creating a more unified approach for modeling CO2 behavior in aquifers. This study provides an overview of practices and workflows for reservoir modeling, particularly focusing on CO2 storage in saline aquifers, with a specific attention to the United States regulations, including those set by the Environmental Protection Agency (EPA). We focus on technical challenges and potential solutions for creating reasonably accurate and scientifically robust GCS dynamic models within aquifers, while considering factors like hydrodynamics, geology, thermophysics, geochemistry, and geomechanics. Our goal is to provide a valuable resource to both industry stakeholders and academic researchers, enhancing the understanding of GCS dynamic modeling implementations and directing future research and development efforts in line with Class VI permit objectives.