Reservoir Geomechanics, Geomechanical Evaluation and Wellbore Stability Handbook/Manual for Students

Abstract

Wellbore stability management is the prevention of unwelcome failure or deformation of the rock surrounding the wellbore due to mechanical stress or chemical imbalance. Prior to drilling, the mechanical stresses in the formation are less than the strength of the rock. The rock is also in a state of chemical equilibrium, or changing slowly at a rate relative to geologic time (millions of years). Rocks under this equilibrium or near-equilibrium state are stable.