Abstarct: Abstract: Having accurate information about subsurface stresses, especially the minimum horizontal stress, is very necessary and crucial. With access to this information, it is possible to anticipate drilling challenges and provide suitable methods for controlling eruptions, well completion, optimal exploitation, injection, and more. A proper understanding of wellbore stress field data significantly impacts decisions made in all stages of reservoir development, from well design to the final phase of production. The main factor in stress modeling and cavity integrity assessment is the numerical value of the minimum horizontal stress. Insufficient information about subsurface conditions, especially stresses, not only complicates modeling but also reduces its accuracy, thus depriving us of very useful and effective reservoir data. One of the most important aspects of geomechanical studies is understanding subsurface stresses, which greatly influence decisions made in all stages of reservoir development, from well design to the final stage of production. There are various methods for measuring the minimum horizontal stress, including small-scale hydraulic fracturing experiments, downhole pressure sensors, leak-off tests, and extensive leak-off tests. Leak-off tests are essential for all wellbore casings. In this research, initially, a one-dimensional geomechanical model of the formation containing the well is constructed using well petrophysical data with the GeoLog software. In this phase, the geomechanical properties of the formation are estimated, and a three-dimensional numerical leak-off test (LOT) model is created using ABAQUS software, considering well environmental conditions, to investigate the causes of formation failure. Sensitivity analysis and parametric study are then carried out to examine the effect of various parameters on formation failure and the test results. The results indicate that elasticity modulus, permeability, and porosity have an insignificant effect on formation failure in this test, while other parameters, when their values are changed, lead to an increase in plastic strain and formation failure.