Perforating a gas well efficiently requires applying technological advances to carry out a safe operation without compromising well productivity. In this paper, is discussed the application of a pre- job plan methodology called perforating well on paper to the perforation operation of SITRA 3-4. This methodology involved tension simulation, perforating gun and charge selection, conveyance hardware optimization, best underbalance value selection, as well as modeling of gun shock, gun movement and reservoir behavior when shooting multiple zones with different pressure regimes. Simulation methodology was performed as well real time during the perforating job to optimize static and flowing underbalance without compromising the safety of the operation and maximizing production gains.