Vertical Borehole Stability Analysis in Injection Well using Numerical Modelling

Abstract

Vertical borehole stability analysis is one of the important aspects of wellbore monitoring in petroleum industry, especially in oil and gas production. In this paper, a wellbore which is going to be turned into an injection well as a part of EOR (Enhanced Oil Recovery) program will be modelled in a form of two-dimensional horizontal cross section of the well to help analyze the rock mechanics parameters as a part of the wellbore stability analysis. The horizontal cut must be in the area that includes shale and
sandstone that has been determined mechanically. The model in this paper applied a numerical modelling method that is often used in geomechanical modelling for tunneling: Finite Element Method (FEM). At a depth of approximately 224 m, both strength factor and displacement around the borehole will be used to interpret the borehole stability. Besides modelling, a data log of the wellbore will be determined by using a simple estimation that shows some parameter curves to indicate the wellbore stability as well. Model results showed that the borehole is stable with strength factor ranged between 3.20-5.53.