This book presents the theory and technologies of drilling operations. It covers the gamut of formulas and calculations for petroleum engineers that have been compiled over several years. Some of these formulas and calculations have been used for decades, while others help guide engineers through some of the industry’s more recent technological breakthroughs. Comprehensively discussing all aspects of drilling technologies, and providing abundant figures, illustrations and tables, examples and exercises to facilitate the learning process, it is a valuable resource for students, scholars and engineers in the field of petroleum engineering.