In this research, two criteria have been used: the Mohr–Coulomb (M–C) criterion plus the multi-weak-aircraft strength criterion for shale formations. They are used to perform research and achieve the optimization of the failure criteria for shale–sandstone interbedded reservoirs. Lamellar shale oil reservoirs acquire millimeter-to-centimeter-scale siltstone and mud shale complexes https://elliotncvfm.ourabilitywiki.com/11073457/about_wellbore_stability_in_drilling