Chapter 4 - Drilling fluids

Abstract

Drilling fluids have evolved from humble beginnings into advanced technology responsible for many critical functions in well construction. Essential functions such as formation pressure management, wellbore stabilization, and cuttings transport are derived from the physical and chemical properties of the drilling fluid, and these properties result from the underlying fluid design and formulation of chemical additives. Throughout the history of well construction, the suite of accessible chemical additives and fluid formulations along with knowledge of how these chemistries interact with the formation during drilling has increased significantly. These advancements have resulted in enhanced fluid performance allowing for the successful drilling of increasingly complex wells. In this chapter, a comprehensive analysis will be performed on drilling fluid functions, properties, formulations, and applications for a range of fluid systems including conventional clay-based aqueous systems and emulsion-based nonaqueous systems, reservoir drilling fluids, and the more recently developed high-performance aqueous and nonaqueous fluids.