Written by a leading industry specialist, a must-have for drilling specialists, petroleum engineers, and field practitioners, this is the only book providing practical, rigorous and validated models for general annular flows, eccentric geometries, non-Newtonian fluids, yield stresses, multiphase effects, and transient motions and flow rates and includes new methods describing mudcake integrity and pore pressure for blowout assessment. Wilson C. Chin has written some of the most important and well-known books in the petroleum industry. These books, whose research was funded by the U.S. Department of Energy and several international petroleum corporations, have set very high standards. Many algorithms are used at leading oil service companies to support key drilling and well logging applications. For the first time, the physical models in these publications, founded on rigorous mathematics and numerical methods, are now available to the broader industry: students, petroleum engineers, drillers and faculty researchers. The presentations are written in easy-to-understand language, with few equations, offering simplified explanations of difficult problems and solutions which provide key insights into downhole physical phenomena through detailed tabulations and color graphics displays. Practical applications, such as cuttings transport, pressure control, mudcake integrity, formation effects in unconventional applications, and so on, are addressed in great detail, offering the most practical answers to everyday problems that the engineer encounters. The book does not stop at annular flow. In fact, the important role of mudcake growth and thickness in enabling steady flow in the annulus is considered, as is the role of (low) formation permeability in affecting mud filtration, cake growth, and fluid sealing at the sandface. This is the first publication addressing "the big picture," a "first" drawn from the author's related research in multiple disciplines such as drilling rheology, formation testing and reservoir simulation. A must-have for any petroleum engineer, petroleum professional, or student, this book is truly a groundbreaking volume that is sure to set new standards.