Multiphase History Matching by Finite Element Approximation in Porous and Naturally Fractured Reservoirs

This paper describes an application of optimal control meth ods to a wide range of history matching problems arisen dur ing oil and gas field development. A conjugate gradient met hod is used to minimize an objective function value. To det ermine a step value along the corresponding conjugate direc tion, a new high effective procedure is set up. The procedu re significantly increases the convergence rate. A new, more accurate form of adjoint problem is obtained that allows to improve the gradient accuracy calculation for the problems with high unlinearities. The parameterization of k(x) and m(x) distributions is considered and the results of numeric al testing of the algorithms are presented.