Numerical Simulation Analysis of Wellbore Stability in Weak Interlayer of Igneous Rock

Wellbores drilled in igneous formation with weak interlayers face significant risk of instabilities. This study aims to investigate the underlying mechanisms these instabilities by employing a combination rock mechanics tests and numerical simulation techniques. The mechanical properties rocks are evaluated determine core strength parameters analyze impact drilling fluid immersion on strength. two-dimensional model is refined, theoretical derivations made, including linear elasticity principal equation extent plastic zone within wellbore. A developed using ABAQUS wellbore stability interlayer formation, accounting for conditions. simulations focus four key aspects formation: strength, permeability, horizontal in-situ stress anisotropy, abnormal pore pressure. findings indicate that strengthening effectively mitigates instability. Moreover, permeability exhibits minimal formation. However, an increase anisotropy pressure both decrease along direction maximum stress.