This comprehensive guide distills nearly two decades of research and teaching into a clear, application-focused resource on geological CO2 storage (GCS) modeling tailored specifically for petroleum engineers. While GCS modeling has historically been driven by physics, mathematics, and hydrogeology, petroleum engineering CO2 modeling often requires a different approach. This book translates complex, multidisciplinary CO2 geological modeling techniques into a unified, petroleum engineer-friendly framework. Unlike generic carbon storage resources, this book connects carbon storage engineering theory directly to CCS field application for petroleum engineers. You'll learn how to integrate CO2 injection modeling into established reservoir engineering workflows, run Excel CO2 storage modeling tutorials, and apply geological carbon storage techniques to practical decision-making. The book features Excel-based modeling exercises, interactive quizzes, and practical examples that reinforce key concepts and build technical mastery--making it ideal for both self-study and team training in carbon storage simulation. Whether your focus is CO2 sequestration engineering, enhanced oil recovery CO2 modeling, or transitioning from oil and gas to carbon storage, this is the go-to reference for mastering CO2 storage with clarity and confidence.