CO2 emissions are a major driver of global warming, contributing significantly to the level of climate change. One promising solution to mitigate this issue is Carbon Capture and Storage, which involves capturing CO2 emissions from industrial sources and securely storing them in reservoirs or aquifers. The study investigates the impact of large-scale reservoir heterogeneity on the efficiency of the CO2 storage by using reservoir models inspired by the Sobrarbe Deltaic Complex outcrop in Ainsa, Spain. Utilizing Google Earth, RRM (Rapid Reservoir Modeling), and CMG software, different reservoir realizations were created, incorporating various levels of petrophysical properties and impermeable layers within the reservoir. The models simulated 100 years of CO2 injection and monitoring. Results indicate that the Base Model, characterized by continuous impermeable layers and high porosity and permeability values, represented the highest cumulative trapped CO2, capturing approximately 3 billion kg of CO2. Models with patchy impermeable layers and lower petrophysical properties values represented lower CO2 trapping efficiency. The results highlight the critical role of reservoir heterogeneity in determining the storage potential and pressure stability of CO2 storage projects, offering valuable insight into the feasibility of carbon storage initiatives.