Research Projects

The international movement toward carbon neutrality and energy transition has put geological storage of other gases, including CO₂ and H₂, at center stage (Hou et al., 2024). Sequestration of CO₂ in underground geological formations is an established concept globally, however, it is still in the emerging implementation phase in India. Similarly, underground hydrogen storage is gaining interest as a critical enabler for grid-scale energy buffering in green hydrogen economies (Ma et al., 2024). In recent years, there is increasing appeal in the symbiotic storage of both CO₂ and H₂ in shale formations. Understanding how these gases would affect the propagation of fractures in shales is important for assessing their mechanical response during injection and for informing safe design for their subsurface storage. The proposed project aims to model fracture behavior during CO₂ and H₂ injection in Indian shale formations of contrasting thermal maturities. Classical fracture models such as Perkins-Kern-Nordgren (PKN) and the Khristianovic-Geertsma-de-Klerk (KGD) will be used to simulate fracture length, aperture, and net pressure under both fluids. Implementation of these models are suitable for extremely low-permeability rocks such as shale due to the dominant fracture growth mechanism in such rocks is pressure-driven mechanics (Yan et al., 2024). Strength and elastic properties of shales [uniaxial compressive strength (UCS), tensile strength, Young’s modulus, Poisson’s ratio, and brittleness] and source rock geochemical properties (organic content, mineralogical composition, and maturity) will be obtained through laboratory analysis to inform simulations. These inputs will be used to run simulations in a Python-based modelling framework which will apply classical PKN and KGD equations (Pradhan et al., 2025). Shales of varying thermal maturities will be chosen to study the role of organic matter transformation on the mechanical behavior (brittleness and elastic response) of the rock both of which can impact how fractures propagate through the rock. Since these mechanical parameters are directly utilized in the models, the effect of thermal maturity on the fracture behavior will be indirectly assessed through simulation results. By parametrizing the low viscosity and high compressibility of H₂ compared to CO₂, the proposed study will provide valuable first-order insights into fracture growth behavior under different injection scenarios. The novel aspect of this research includes first analytical numerical modelling comparison of CO₂ and H₂ injection induced fracture propagation in shales obtained from Indian shale formations. This work supports India’s Green Hydrogen Mission, which needs underground storage of hydrogen (Nikhil et al., 2024), and aligns with the country’s carbon capture utilization and storage (CCUS) roadmap focused on safe subsurface storage to meet net-zero goals by 2070.