Study Of The Physicochemical Properties Of Drilling Fluids And Their Influence On Drilling Performance

Abstract

This thesis investigates the physicochemical properties of drilling fluids and their influence on drilling performance, with particular emphasis on their role in optimizing well construction operations. Drilling fluids are complex engineered systems whose behavior depends on a combination of physical, chemical, and thermal properties that must be continuously controlled throughout the drilling process. The study begins with a general overview of drilling fluids, including their classification, composition, and primary functions in ensuring wellbore stability, pressure control, cuttings transport, and formation protection. It then presents a detailed analysis of the key physicochemical properties, such as density, rheology, filtration behavior, pH, salinity, and temperature effects, highlighting their interdependence and impact on fluid performance under downhole conditions. Furthermore, the thesis examines the influence of these properties on drilling performance indicators, including rate of penetration (ROP), hydraulic efficiency, hole cleaning, and operational stability. The results demonstrate that drilling performance is governed by a complex interaction of multiple parameters rather than a single factor, requiring a balanced and optimized fluid design. A case study of the BRSSW-1 well is presented to illustrate the practical application of drilling fluid engineering. The analysis shows that the implemented mud program, based on adaptive control of physicochemical properties across different drilling intervals, successfully ensured efficient drilling operations, minimized formation damage, and maintained wellbore stability. Overall, this work confirms that the proper selection, design, and continuous monitoring of drilling fluid properties are essential for optimizing drilling performance, reducing operational risks, and preserving reservoir integrity.