Mixed Impem/Implicit Techniques for Compositional Modeling of Flow in Porous media
Wednesday, March 13, 2002 - 11:00am - 12:00pm
Rick Dean (The University of Texas at Austin)
Compositional simulations of porous media typically involve 5 to 20 components per grid block for complex EOR processes. Because of this, implicit techniques require a large amount of memory and each time step can take a significant amount of CPU time. Impem (IMplicit Pressure Explicit Mass) techniques require less memory and use less CPU time per time step. But impem techniques often require many more time steps for the same simulation. Mixed impem/implicit techniques attempt to capture the benefits of both techniques while avoiding the drawbacks that are inherent in each technique. Mixed impem/implicit techniques are discussed for simulations that contain multiple grids where some grids use a time discretization that is implicit and other grids use a time discretization that is impem. In addition, linear solution techniques are discussed for mixed impem/implicit problems. Examples of mixed impem/implicit simulations will be presented.