Determining the optimal drilling mud density an‎d predicting wellbore stability are among the primary challenges in the drilling industry. Due to geological complexities an‎d the diversity of drilling conditions, the use of precise analytical methods an‎d numerical modeling is of particular importance for eva‎luating wellbore stability. In this study, a comprehensive three-dimensional model of the geological formation an‎d the drilled well was developed using FLAC3D software. This model accurately simulates the complex behavior of rock under drilling-induced stress conditions. The main objective of this research is to eva‎luate an‎d compare various rock failure criteria under different drilling scenarios. In the modeling process, multiple failure criteria—including Mohr-Coulomb, Drucker-Prager, an‎d Hoek-Brown—were applied, an‎d the results from each were compared with actual drilling data. Based on the outcomes of the numerical simulations, the Hoek-Brown criterion yielded the most reliable results. Another key achievement of this study is the determination of the safe pressure range for drilling mud. Using the modeling results, the minimum an‎d maximum mud pressures required to maintain wellbore stability were identified. This enables drilling engineers to selec‎t the most appropriate mud density an‎d prevent incidents such as wellbore collapse. Ultimately, the findings of this research can serve as a powerful tool for optimizing drilling operation design an‎d reducing associated costs. Through FLAC3D-based 3D modeling, various drilling scenarios can be simulated, an‎d the impact of changes in different parameters on wellbore stability can be thoroughly assessed.

لهراسب فرامرزي

عليرضا باغبانان , سعيد مهدوي