Reservoir compartmentalization Reservoir compartmentalization the segregation of a petroleum accumulation into a number of individual fluid pressure compartments controls the volume of moveable oil or gas that might be connected to any given well drilled in a field and consequently impacts booking of reserves and operational profitability. This is a general feature of modern exploration and production portfolios and has driven major developments in geoscience engineering and related technology. Given that compartmentalization is a consequence of many factors an integrated subsurface approach is required to better understand and predict compartmentalization behaviour and to minimize the risk of it occurring unexpectedly. This volume reviews our current understanding and ability to model compartmentalization. It highlights the necessity for effective specialist discipline integration and the value of learning from operational experience in: detection and monitoring of compartmentalization; stratigraphic and mixed mode compartmentalization; and fault dominated compartmentalization P. 4 of cover