Infill well wellbore stability analysis by considering plasticity, stress arching, lateral deformation and inhomogeneous depletion of the reservoir

Abstract The traditional way of analyzing wellbore stability of infill wells relies on the analytical solution of the stress path, which assumes uniaxial strain, homogenous depletion, constant overburden stress, and linear elastic condition. The objective of this study is to re-evaluate all the above four assumptions and analyze the plasticity, stress arching, lateral deformation and inhomogeneous depletion of the reservoir. Coupled geomechanics and fluid flow analysis is conducted to get the time and location dependent stress field and pressure field, which serve as inputs for wellbore stability analysis for infill wells. Considering four cases, the ranking according to the width of the safe drilling mud weight windows is 1) plasticity, 2) elasticity, 3) plasticity with stress arching, and 4) elasticity with stress arching. This coupled geomechanics and fluid flow can provide dynamic information concerning where to drill, when to drill, and how to drill for infill wells.