Repository Simulation is a reservoir designing in which the model is created to foresee the stream of fluids (oil, gas, and water). The model is produced utilizing PCs with the assistance of very modernized software. It is developed to suspect whether the stream is right or off base. The reservoir designing consider both internal as well as external factors. A reservoir model represents the physical space of the reservoir by an array of discrete cells, delineated by a grid which may be regular or irregular. The array of cells is usually three-dimensional, although 1D and 2D models are sometimes used. Values for attributes such as porosity, permeability, and water quality are associated with each cell.