Fundamentals of Reservoir Simulation

Publisher Summary This chapter discusses the fundamentals of reservoir simulation. The goal of this chapter is to describe how the complex fluid flow equations are presented. The chapter presents the technique used to solve the set of IFLO equations that is presented as an illustration of a simulator solution procedure. The two most common solution procedures in use today are implicit pressure, explicit saturation (IMPES), and Newton–Raphson. The chapter illustrates that the three primary unknown variables for an oil-water-gas system are oil-phase pressure, water saturation, and either gas saturation or solution gas-oil ratio. Naturally, the choice of unknowns is different for a gas-water system or a water-only system. The chapter provides a discussion that applies to the most general three-phase case. It also presents a representation of the reservoir that is quantified in the reservoir flow simulator. In conclusion a representation of the reservoir is quantified in the reservoir flow simulator. The representation is validated during the history matching process, and forecasts of reservoir performance are then made from the validated reservoir representation.