Correcting Inflow Performance Relationship Curves for Explicitly Coupling Reservoir Simulations and Production Systems Simulations

There are many ways to integrate reservoir and production system simulations to forecast production, in a single model (implicit) or in coupled models (explicit). Explicit coupling, a simple and flexible coupling method, has the advantage of using commonly available commercial software to integrate reservoir and production systems simulations. However, explicit coupling may produce large deviations as the inflow performance relationship (IPR) curve, which combines well pressure and production and injection rates, can only be evaluated or amended at the beginning of a time-step. As the IPR curve changes during a time-step, it may be necessary to correct unstable results for well pressure and rates. Using a previously proposed IPR correction method, numerical stability was improved, reducing deviations during advancing the time step. A formula was created to support the correction of IPR curve. The methodology was tested using cases with known responses for pressures and flow rates, for a predetermined production strategy from the benchmark case UNISIM-I-D. Deviations were reduced to near zero when compared with uncoupled and decoupled methodologies to integrate reservoir with production system simulations.