Sedimentary rocks are heterogeneous and this heterogeneity affects fluid flow. Hence to make an accurate production estimate one needs to make a reservoir model that carries the effects of geological features on two-phase fluid flow. This work proposes a systematic procedure for the design of a reservoir model that represents fluid behaviour of all heterogeneities. The procedure consists of the following steps: establish a geological model that holds all sequences and facies (flow) units; identify the bed type (flow cell) for each facies unit and determine its porosity and permeability; run a numerical flow simulation on each flow cell; run a flow simulation on the reservoir. Key elements different from existing approaches are: geological model is build hypothetically and populated by all expected facies; lamina porosity and permeability are sampled with bias and relative permeability is obtained for each flow cell. Thus the ensuing reservoir model includes all effects of capillary trapping. This book serves students and professionals in geology and engineering who aim to make quick and adequate reservoir models.