The invention relates to fluid reservoir analysis and more particularly to a computer system and method for modeling fluid depletion.
Underground reservoirs of petroleum fluids are depleted as the fluids are displaced toward production wells. Primary or secondary type recovery methods that are well-known to specialists can be used in order to better displace petroleum fluids towards production wells. In addition, new production wells can be drilled after initial depletion Adequate modeling of fluids that have been withdrawn from a reservoir and fluids that remain in the reservoir allows for both additional production wells and primary or secondary recovery methods to be more effectively employed to increase the recovery of petroleum fluids from a partially depleted field. The partially depleted field becomes more valuable as a result of the modeling that allows the subsequent use of the techniques under consideration.
Original analysis of the underground reservoir using coring, logging, seismic, or other techniques can produce information about the three dimensional extent of the reservoir and the amount of fluids therein. Obtaining sufficient data for an accurate description is expensive, and additional analysis for a partially depleted reservoir is generally not cost effective. If production has been monitored, the amount of petroleum fluids removed is a known quantity; however, it is generally difficult to determine the current state of fluids in a reservoir based only on the amount produced and the knowledge of the original state.