2D and 3D Elastic and Poroelastic Stress Analyses for Multilateral Wellbore Junctions

ABSTRACT: Stress and pore pressure variations due to the introduction of multilaterals from a main well bore are analyzed herein. Wellbore stability for multilateral junctions are increasingly becoming the oil and gas industry's concerns, and the placement of the multi-laterals branches with the respect to the in-situ stresses could enhance or compromise the stability of the branch and/or even the mother wellbore itself. Open hole completion or well bore casing placements are decided while taking into account rock poromechanical parameters values as well as the rock strength. Poromechanical analyses were undertaken to estimate the redistribution of stresses and pore pressures once the multi-lateral branch has been drilled with an optimum location due to the existing mother well. The paper presents the geomechanical effects and assesses the significance of the pore fluid pressure on the stress redistribution, within the realm of the coupled theory of poroelasticity due to the creation of the junction.