In complex reservoirs with geological discontinuities, such as faults, the risk in the production of oil and gas are increase by the injection methods frequently used. The injection and depletion processes induce stress variations in the formation. These can be high enough to reactivate faults and significantly modify the behavior of the reservoir, bringing on one of the most critical situations in the oil industry. In this context, this dissertation investigates the phenomenon of fault reactivation by employing the finite element method based on an explicit representation of the fault with interface elements. In addition, a fault zone model based on an equivalent continuum approach is adopted for comparison. The pressure limits during production of oil reservoirs considering fault reactivation are determined from pore-elastoplastic uncoupled analyses with the software Abaqus. With this purpouse, interfaces elements with Mohr-Coulomb constitutive model were implemented through user subroutine in Abaqus to represent, in an approximate way, the fault behavior. In addition, other tools were developed to facilitate the generation of the models to be analyzed. The presented methodology was evaluated and verified through the simulation of a synthetic model with a normal fault. The results were compared with a simplified analytical approach and the results obtained by finite element simulator AEEPECD (Costa, 1984). Some examples of applications are presented, in which faults are represented using interface elements and alternatively, through an equivalent continuum approach. The analysis results demonstrate the applicability of the methodology to real fields.