Estimation of Multiple Petrophysical Parameters for Hydrocarbon Reservoirs with the Ensemble-Based Technique

The ensemble-based history matching technique has been successfully applied to simultaneously estimate multiple petrophysical parameters for hydrocarbon reservoirs. The tuning petrophysical properties include horizontal and vertical permeability, porosity and three-phase relative permeability curves. Four scenarios with different combination of the tuning parameters have been evaluated. The ensemble-based history matching technique is found to be capable of estimating multiple petrophysical parameters by conditioning the reservoir geological models to production history. The uncertainty range of production data generated from the updated models is reduced compared to that of initial models. However, the history-matched models may not always provide good production prediction results, especially when absolute permeability and relative permeability are tuned simultaneously. This further illustrates the non-uniqueness of the history matching solutions. In addition, three-phase relative permeability curves are found to be estimated with good accuracy when absolute permeability fields are known. Key words: Petrophysical parameters; Assisted history matching; Ensemble kalman filter (EnKF); PUNQ-S3 model