Managed pressure drilling is a developing technology that is promising to reduce costs and improve efficiencies, particularly in difficult wells. IADC’s definition is that MPD is an adaptive drilling process used to precisely control the annular pressure profile throughout the wellbore. This facilitates faster corrective action when pressure variations occur, as well as enabling drilling of otherwise “undrillable” wells. Topics include determining whether wells are MPD candidates, methods and advantages, situational challenges and solutions and common equipment used in MPD operations. Published under the auspices of the IADC Technical Publications Committee. 369 pages. Elsevier, 2009.