Addressing both steady and unsteady-state fluid flow and related heat-transfer problems, the Second Edition of Fluid Flow and Heat Transfer in Wellbores strikes the perfect balance between theory and practice to aid understanding. Three new chapters on application of theory have been added and include probing pressure traverse in various wellbore multiphase fluid-flow situations, estimating flow rates from temperature data, translating off-bottom transient-pressure data to that at the datum depth, and a detailed discussion around newly discovered wellbore safety and integrity issues. Fundamental aspects of drilling, fluid circulation, and production operations form the foundation of this update of the 2002 original publication.The book addresses the coupled fluid/heat flow issue as encountered in many practical production/operation problems, including in drilling. Both steady- and unsteady-state transport problems are considered. Even when steady fluid flow is maintained during circulation, injection, or production modes, unsteady heat transport in the formation occurs nonetheless. Fluid circulation during drilling and workover operations and injection of annular gas in a gas lift operation are cases in point. The book also examines fully transient processes of fluid and heat flows, such as those in drill stem or production testing.