Geomechanics While Drilling: Advanced Real-Time Azimuthal LWD Measurements Enable Proactive Wellbore Stability Management

Abstract

Managing wellbore stability remains a critical challenge when drilling highly deviated and horizontal wells, particularly in heterogeneous carbonate formations where variations in rock strength and in-situ stress conditions can lead to rapid borehole deterioration. Instability mechanisms such as breakouts, washouts, and ledge formation can result in tight spots, stuck pipe incidents, and increased nonproductive time (NPT). Traditionally, identification and analysis of such mechanisms relied mainly on surface cuttings analysis or post-drilling wireline image logs and caliper measurements, limiting the ability to diagnose and mitigate instability while drilling operations are still underway. This paper presents field applications demonstrating how advanced logging-while-drilling (LWD) azimuthal measurements can be used to monitor and manage wellbore stability in real time. Recent advancements in LWD technology have introduced high-resolution azimuthal measurements capable of providing continuous real-time insight into borehole geometry and formation response. Next-generation LWD systems integrating ultrasonic borehole imaging, azimuthal caliper measurements, drilling dynamics, and conventional formation evaluation logs enable continuous monitoring of wellbore conditions while drilling. The ultrasonic LWD imaging sensor provides full 360° borehole coverage and high-resolution measurements of borehole shape and diameter while drilling. Stress-induced borehole breakouts appear on the ultrasonic image as characteristic paired enlargements approximately 180° apart, representing wellbore deformation related to in-situ stress conditions. Simultaneous azimuthal caliper measurements allow quantitative evaluation of borehole ovality and enlargement, enabling early detection of instability mechanisms. The integration of these measurements with drilling parameters such as effective circulating density (ECD) allows real-time interpretation of wellbore stability conditions. Field examples from highly deviated carbonate wells demonstrate how these measurements were used to diagnose wellbore instability and guide operational decisions. In several cases, early breakout development was detected shortly after reductions in ECD. Real-time ultrasonic imaging and azimuthal caliper responses revealed increasing borehole ovality and enlargement, indicating insufficient wellbore support from the drilling fluid. Operational adjustments, including increasing ECD through mud weight optimization or applying downhole back pressure, resulted in improved borehole stability and reduced breakout development. In other intervals, comparison between measurements acquired while drilling and during tripping out of the hole provided insight into time-dependent wellbore deterioration associated with prolonged exposure time. These observations helped explain and mitigate tight spots and stuck pipe events during subsequent operations. This work demonstrates a practical geomechanics-while-drilling workflow enabled by high-resolution azimuthal LWD measurements. The integration of ultrasonic borehole imaging and azimuthal caliper data with drilling parameters allows early detection of wellbore instability mechanisms and supports proactive operational decisions while drilling. The presented field cases highlight how real-time borehole stability monitoring can reduce drilling risks, improve wellbore integrity, and enhance well construction efficiency in complex carbonate reservoirs.