Reservoir Simulation

Dr. Hales heads the reservoir simulation research at IRSRI.

Reservoir simulation is the use of computers to simulate the underground flow of fluids in oil fields. Computer programs known as "reservoir simulators" allow Reservoir Engineers from the Petroleum Industry to predict the production histories of their oil reservoirs. These simulators allow the optimization or hydrocarbon recovery by creating virtual production histories using a wide variety of possible development schemes. Engineers can experiment with various injected fluids, e.g. water, CO₂, nitrogen, surfactants, or steam. They can also experiment with various well locations, geometries, and completion intervals. Matching actual historic reservoir pressures and produced volumes with simulated histories also allows engineers to better determine reservoir properties.

Reservoir simulation became possible some thirty years ago with the advent of computers. Since that time the technology has increased greatly in capability as computers have become more powerful. However, despite enormous growth in speed and size that computers have seen, reservoir simulation still taxes the largest and fastest systems. The need for improved mathematics which will allow faster and more accurate simulations has never been greater. The utility of several emerging technologies depend, to a great extent on faster, more accurate simulators:

• Automatic History Matching allows the computer to fine-tune the voluminous data describing the reservoir by running many simulations with slightly differing data to provide a match between actual histories and simulated histories.
• Geostatistics allows geologists and geophysicists to provide a large number of different reservoir descriptions which have some probability of representing the reservoir. Simulation of each of these descriptions allows the determination of the probability of various production levels throughout the life of the field.
• Automatic Optimization Techniques use many successive simulations to determine reservoir development plans which provide the best possible reservoir recovery and/or income.