History Matching Geostatistical Reservoir Models with Gradual Deformation Method

Abstract

Abstract This paper presents a new history matching methodology to constraint 3-D geostatistical reservoir model to well and production data. This methodology is a general inversion procedure based upon the gradual deformation method. It allows for constraining simultaneously petrophysical, geostatistical and reservoir parameters to dynamic production data. The gradual deformation algorithm creates realizations, which evolve smoothly while preserving the global statistical features of the model. The deformation process is coupled with an optimization algorithm to automatically match production history. After validating the inversion process on synthetic data, we focused on real data. The inversion process involves up to fourteen parameters constrained through a fifteen-year production history. A coarse geostatistical model conditioned to rock-types and porosities observed at well locations describes the geological uncertainties. The petrophysical uncertainties are summarized within the permeability-porosity laws considered for the two dominant rock-types in the reservoir. The main reservoir uncertainties are the strengths of the edge aquifers and the critical gas saturations for each rocktype. The final match is obtained after several inversions and is quite satisfactory with respect to well pressure, oil and water flow rates.