Analysis of Wellbore Breakouts and Determination of Horizontal Stress Direction from Four Arm Calipers – A Study from Gulf of Kutch, Western Offshore Basin 8th February 2022 – Posted in: Geo Pressure
11th Biennial International Conference & Exposition, Paper ID –37, SPG Jaipur, India, Dec 4-6, 2015
Wellbore instability costs includes billions of dollar per year worldwide because of down hole drilling problems and majority of problems occurring are related to mechanical instability of wellbore. When the stresses exceed the limit of rock strength it fails and if failure is too severe drilling problems occur. It is nearly impossible to drill perfectly gauge hole without any wellbore breakouts, but our aim should be to avoid catastrophic failure and to keep the borehole in the ambit of modest intensity of breakouts and successfully drill the well with limited complications. Each drilled well provides tremendous amount of information about stresses around wellbore. If subsurface Geological and Geophysical data is studied clinically, prevention of catastrophic wellbore failure can be ensured. Breakout data analysis of drilled wells is an important tool in understanding present-day stress conditions in areas where more detailed stress measurements are not available. An understanding of in situ stress conditions is essential to evaluate the potential for slip on existing faults. In petroleum industry, knowledge of borehole stress conditions can be critical in placement of platform and well profile as well as hydraulic-fracturing treatments. The direction of horizontal stresses can be determined with the help of four arm caliper by analyzing borehole ovalisation.