Advances in drilling fluid technology: Recent innovations, performance enhancements, and future trends in high-performance and eco-friendly formulations

Drilling fluids are essential to modern oil and gas operations, providing critical functions such as wellbore stability, cuttings transport, formation protection, and drilling efficiency. This comprehensive review highlights recent innovations in drilling fluid technology, focusing on the development of high-performance water-based muds (HPWBMs), oil-based muds (OBMs), synthetic-based muds (SBMs), and nanotechnology-enhanced systems. Advances in rheological control, fluid loss reduction, shale inhibition, and thermal stability are systematically analyzed. Special emphasis is placed on the shift toward environmentally friendly drilling fluids, including biodegradable additives, bio-based polymers, and green lubricants. The integration of real-time monitoring, artificial intelligence (AI), and machine learning (ML) into fluid optimization and design is also discussed. Furthermore, this review outlines critical technical, environmental, and regulatory challenges, highlighting future research directions such as hybrid rheological modeling, self-healing fluids, and life-cycle assessment (LCA) integration. The insights presented aim to support the development of next-generation drilling fluids that are efficient, adaptive, and aligned with sustainability goals.