Chapter 9: Challenges in Reservoir Simulation of Unconventional Technologies

This chapter first discusses heat and mass transport in the context of advanced recovery processes. The object of this discussion is to point out the origin of numerical stiffness in the mathematical formulation that gives rise to the relatively large computational effort needed to solve some problems. The inclusion of geomechanics is also touched upon briefly. The next topic is selection of a model and the population of the model with parameters. A summary of simulation studies of advanced recovery concepts rounds out the chapter.

Access to modern numerical reservoir simulators has changed engineering practice for conventional oil reservoirs and has had an equal or greater impact on production of heavy and viscous oil. Reservoir simulation has provided the opportunity to calibrate models with laboratory data and test the feasibility of production concepts before field implementation, has aided interpretation of pilots and field projects, and has improved our insight regarding dominant physical mechanisms. Attempts to history match field project results with reservoir simulators have highlighted that the success of a process is governed in a complex way by reservoir heterogeneity (around wells and deeper in the reservoir), well configurations, injection rates, composition of injectants, and phase behavior. Simulation has also provided a platform for selection of optimal recovery process parameters and the sequencing of injectants.