...Yaqing Gu; Dean S. Oliver This paper reports the use of ensemble Kalman filter (EnKF) for automatic history matching. EnKF is a Monte Carlo method, in which an ensemble of reservoir state variables are generated and kept up-to-date as data are assimilated sequentially. The uncertainty of reservoir...

...; however, the outcome may depend on the designer’s judgment and skill. The Monte Carlo method is an almost totally automated approach; it is based on stochastic techniques and may require relatively long run time. The Lagrange multipliers method, in addition to the optimum value for the decision variables...