Verification of Decline Curve Analysis Models for Production Prediction

Reserves and production in petroleum reservoirs can be estimated using empirical and analytical decline curve analysis models. There have been many such models. In this study, three representative models (exponential, harmonic, and the mechanistic Li-Horne models) were chosen to predict and match oil and gas production from both core samples and reservoirs with different permeability. The recovery and reserves were estimated using the three models and the results were compared. The comparison demonstrated that the recovery at an assumed economic limit predicted using the LiHorne model was greater than the exponential model but was less than the harmonic model. Note that the exponential model tends to underestimate reserves and production rates while the harmonic model has a tendency to overpredict the reservoir performance. It was also found that the reserves predicted using the harmonic model were greater than one pore volume in some cases, which is physically impossible. The model predictions using the experimental data of recovery in the core samples were also compared to the true values. The results demonstrated that the Li-Horne model had the best estimation of the recoverable recovery compared to the exponential and the harmonic models in the cases studied.