CO2 can be permanently store in the shale reservoirs and also can be utilised for enhancing the gas extraction from the shale. This chapter focuses on shale rock characterization in terms of mineral composition, porosity, permeability, pore size distribution, and grain density, and also simulation for CO2 storage estimation. The current study is based on both field study, laboratory investigation, and reservoir modelling. CO2 sequestration potential in the Chalbalpur-Mahishmura regions of the Raniganj Field, India was assessed with the help of simulation techniques. The studied shales show the porosity levels between 0.02% and 1.21%, permeability from 0.10 to 1.67 millidarcies (mD), and grain density ranging from 2.40 to 3.09 g per cubic centimetre (g/cc). Simulation results the total cumulative volume of CO2 storage capacity 721,000m3, with around 1296.3 tons of CO2 potentially sequestered over 300 to 400 days within the shale reservoir.