Drilling Challenges in Active Tectonic Folded Zones Using Solid Material Mechanism for Bending

ABSTRACT: This study aims to address the formidable challenges of drilling in active tectonic folded zones, characterized by their complex geomechanical behavior and unpredictable stress regimes. By applying solid material mechanics principles, particularly the mechanism of bending, the objective is to develop a predictive model that can guide drilling operations in these environments, reducing the risk of structural failure and improving operational safety and efficiency. A multi-faceted approach is adopted, beginning with the analysis of strain and stress distribution under bending forces, as illustrated by solid material mechanics. Numerical simulations are conducted to model the mechanical behaviour of drill strings in response to the heterogeneous stress fields typical of folded tectonic structures. Field data from existing drilling operations in active folded zones are incorporated to refine the model, which is subsequently validated through laboratory experiments using scaled analog materials that replicate the mechanical properties and stress conditions of the target geological formations. The research identifies critical stress thresholds and deformation patterns that are indicative of potential drilling hazards. It also demonstrates that strategic drill path planning, based on the model's stress distribution predictions, can significantly reduce the incidence of drill string failures. The correlation between the predicted and observed performance of drilling equipment under simulated conditions exhibits a high degree of accuracy. The innovative aspect of this study lies in its integrative use of solid material mechanics for real-world application in drilling technology, transcending traditional empirical approaches. The predictive model developed not only provides a scientific basis for drilling in complex geomechanical settings but also introduces a novel methodological framework that can be adapted to various subsurface engineering challenges. Introduction Drilling in tectonically active folded zones presents significant geomechanical challenges due to the complex stress fields and deformations caused by continuous tectonic movements (Wiener et al., 1997). These regions are characterized by intricate fault systems, high in-situ stresses, and intense folding of subsurface layers. The structural deformation in such areas leads to varying stress concentrations, increasing the risk of wellbore instability, mechanical failure, and complications during drilling operations (Ahmed et al., 2017).