The advantages of the streamline methods are their exceptional simulation speed and less dispersed solutions. However streamlines provide limited abilities, compared to finite-difference simulators. One of such drawbacks is lack of capillary effects, which may be crucially important in heterogeneous and fractured reservoirs. The book starts with an introduction into the fluid flow in the porous media and capillary effects. In the second chapter the mathematical formulation of the governing equations with capillary effects are presented. A Capillary-Viscous Potential (CVP) is introduced as...