Reservoir simulation is an area of reservoir engineering in which computer models are used to predict the flow of fluids (typically, oil, water, and gas) through porous media. The amount of oil & gas recoverable from a conventional reservoir is assessed by accurately characterising the static recoverable volumes and history matching that to dynamic flow. Reservoir performance is important because the recovery changes as the physical environment of the reservoir adjusts with every molecule extracted; the longer a reservoir has been flowing, the more accurate the prediction of remaining reserves. Dynamic simulations are commonly used by analysts to update reserves volumes, particularly in large complex reservoirs. Daily production can be matched against production forecasts to establish the accuracy of simulation models based on actual volumes of recovered oil or gas. Unlike analogs or volumetric methods above, the degree of confidence in the estimates (or the range of outcomes) increases as the amount and quality of geological, engineering and production performance data increase. These must then be compared with previous estimates, whether derived from analog, volumetric or static reservoir modelling before reserves can be adjusted and booked.
