Advancements, Challenges, and Perspectives of Flue Gas Injection in Subsurface Formations: A Comprehensive Review

Flue gas injection into subsurface formations has emerged as a promising approach for enhanced oil and gas recovery, as well as geological carbon sequestration. Extensive numerical and experimental studies have been conducted to explore the effectiveness of flue gas injection. In this comprehensive review, we organize an overview of the main sources of flue gas and their compositions across various industries. We examine different flue gas injection types coupled with enhanced oil and gas recovery methods. Additionally, we summarize the evaluation methods for gas storage capacity found in the literature, which can guide the development of advanced theoretical models and simulation tools. The impact of flue gas injection patterns on recovery factor is analyzed, encompassing both continuous and cyclic flue gas injection strategies. Furthermore, we investigate the effects of fracture and matrix permeability during flue gas injection, as well as the impact of flue gas composition on oil recovery. Moreover, we discuss the intricate geochemical reactions that occur between flue gas compositions, formation brine, and rock. These reactions can lead to significant changes in the chemical equilibrium, affecting the overall process. Recent advancements in numeric modeling techniques are reviewed, including the application of various simulators such as Eclipse, CMG, Petrel, TOUGH2 V2, PHREEQC, and COMSOL to simulate flue gas injection scenarios. These models offer valuable insights by considering the main factors and mechanisms involved. Finally, we address the existing knowledge gaps and provide recommendations for future studies in this field. By further investigating these areas, we can enhance our understanding of flue gas injection processes and optimize their implementation for enhanced gas and oil recovery and carbon sequestration.