One main target in petroleum recovery is the description of of the three-dimensional distribution of petrophysical properties on the interwell scale in carbonate reservoirs, in order to improve performance predictions by means of fluid-flow computer simulations The book focuses on the improvement of geological, petrophysical, and geostatistical methods, describes the basic petrophysical properties, important geology parameters, and rock fabrics from cores, and discusses their spatial distribution. A closing chapter deals with reservoir models as an input into flow simulators.