The impact of overbalance pressure on the alteration of sandstone geomechanical properties

Abstract The overbalance pressure drilling technique is well common and practiced during the operations in petroleum field. This parameter very critical affects drilled formation characteristics, therefore, main objective of current study to evaluate impact that applied operation on rock elastic strength characteristics by employing integrated lab experimental work. Berea Buff sandstone type was utilized interact with water-based fluid (barite-weighted) under an extended range [300 1000 psi]. research presents extensive analyses cover filtration tests for rock-mud interaction, scratch testing determining profile, sonic data acquisition, properties determination, spectrometry scanning electron microscope nuclear magnetic resonance internal pore structure changes. analysis performed before mud interaction saturated samples (base case) after applying different (pre-mud interaction) alterations. obtained results showed high degree wave propagation as compressional shear velocities increased 17 6%, respectively increasing pressure. Poisson’s ratio a stable trend, while Young’s modulus trend 23% increase deterioration behavior unconfined compression decreased 10% tensile 9% reduction. alterations due solids precipitations filtrate integrity interaction. In addition, statistical illustrated relationship between recorded controlling factor