ANALYSIS OF VERTICAL BOREHOLE STABILITY ON INJECTION WELL IN LAPANGAN J USING DEM AND FEM 2D

• Main Author: Pradhitasari, Berliana
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/37204
• Institution: Institut Teknologi Bandung

Analysis of vertical borehole is one of the most important aspect in wellbore monitoring of the petroleum industry. In this thesis, a vertical-shaped injection well that locates in an oil and gas field has been relogged and will be modelled into two conditions; with casing and with casing and cementing, using two methods for comparison: distict element method (DEM) and finite element method (FEM). Model will be in a form of two-dimensional horizontal cross section of the well at particular depth (224 m and 300 m) to help analyse the stability. The horizontal cut must be in the area that includes shale and sandstone that has been determined mechanically and indicates oil trace. The validation was used by analysing data log from the relogging that could read and determine the borehole characteristics until the bottom hole. In modelling the vertical borehole, two methods were applied with result such as maximum displacement happened on the borehole that in the same direction as maximum horizontal stress direction. Results showed borehole with both conditions is stable with consideration of displacement, principal stresses, factor of safety, and strength factor assessment. Data log analysis from relogging also showed that borehole is stable and no indication of breakout showed by pore pressure values that was still lower than mud weight or wellbore pressure values.