Geomechanical Evaluation through Depth-Dependent Elastic Modulus Matrices Derived from Acoustic Log Data

ABSTRACT: Understanding the mechanical behavior of subsurface formations is crucial for wellbore stability, drilling optimization, and reservoir management. This study introduces a geomechanical evaluation approach that leverages depth-dependent elastic modulus matrices derived from acoustic log data to better characterize rock stiffness and anisotropy. This method can then capture low variations in elastic properties. The methodology is applied to the Jubarte Field (Campos Basin, Brazil), utilizing Logging While Drilling (LWD) and wireline measurements to assess the mechanical properties of the sandstone and shale formations. An analysis is conducted using isotropic and vertical transversely isotropic (VTI) models, allowing a more accurate representation of stiffness and compliance variations across depth. The results demonstrate that depth-dependent evaluation of elastic parameters enhances the understanding of geomechanical behavior. These findings underscore the practical value of acoustic log data in improving formation evaluation, particularly in complex lithologies where anisotropic effects play a significant role. The study highlights how integrating acoustic-derived geomechanical properties can lead to better wellbore integrity assessments and optimized reservoir development strategies.