Adoption of CO2 storage on a global scale to mitigate climate change brings the geomechanical risks to the forefront. Induced seismicity poses a major hurdle in the feasibility of carbon capture and storage (CCS) projects. The current study presents a composite geomechanical model for assessing CO2 storage feasibility using the Assam basin in India as a case study. The study highlights the potential risks associated with CO2 injection and storage and provides valuable insights into the use of geomechanical models for evaluating these risks. The model is developed for a depleting oil field (Naharkatiya) that is a prospective pilot storage site in India. The model incorporates in-formation well logs, laboratory experiments, and seismic data to provide inputs for simulating the geomechanical response of the reservoir to CO2 injection. The model is calibrated using observed events and data points, which allows for the accurate estimation of geomechanical parameters and principal stresses. The relative principal stress magnitudes indicate a normal faulting regime in the area. Furthermore, wellbore stability has been estimated using the determination of a safe drilling mud window. The results suggest that the mud weight used is adequate to prevent mud loss against the formation pore pressure and has sufficient margin from the minimum horizontal stress. The shear failure gradient has also been estimated using the modified lade criterion.