This book outlines in detail practical Reservoir simulations. Written by a seasoned practicing simulation engineer, it uses a descriptive style for field application. Mathematical development is kept to a minimum since this is covered in depth in many books and the literature. In particular, the author shows how to link geology and simulation input - the most critical aspect of successful reservoir simulation. The book covers all of the fundamental techniques that are unique to reservoir simulation, such as pseudo-relative permeability. The second half of the book describes advanced studies, compositional modeling, hydraulically fractured and horizontal wells, EOR processes and thermal simulation with a heavy emphasis on steam-assisted gravity drainage (SAGD).