Reservoir Engineering –Steady, Diffusive and Propagation Models - Wave Propagation in Drilling, Well Logging and Reservoir Applications - page 366

is now unknown, the shock velocity cannot be written down a priori , so that the
manner in which the step solution for saturation propagates is uncertain. Strong
nonlinear coupling between the pressure and saturation equations is obtained,
and iterative solutions, as discussed in Chin (2002), are required.
9.2 References
Chin, W.C., Quantitative Methods in Reservoir Engineering , Elsevier,
Amsterdam, 2002.
Muskat, M., Physical Principles of Oil Production , McGraw-Hill, New York,
1949.
Peaceman, D.W., Fundamentals of Numerical Reservoir Simulation , Elsevier
Scientific Publishing, Amsterdam, 1977.