Improved Characterization of Naturally Fractured Reservoirs by Joint Inversion of Production and Seismic AVOZ Data

Abstract

This paper proposes a method for characterization of natural fractured reservoirs by integration of production and seismic data. The method is based on a unified model for the effective hydraulic and elastic properties of fractured porous media (which takes into account the effects of fracture geometry and fracture-fracture interaction in a consistent manner) and a Bayesian method of inversion which provides information about uncertainties as well as mean values. Our method can deal with complex models of fractured reservoirs .However, the initial inversion results presented here are based on a simplified model (involving a single set of vertical fractures). At the same time, the simplified model is both heterogeneous and anisotropic, since the reservoir is assumed to consist of an unfractured zone in addition to a fracture zone (characterized by a fracture density and azimuthal orientation). An application to synthetic data suggests that one may obtain a significantly better estimate of the parameters of the fractures within a fractured reservoir by using seismic AVOZ data in addition to reservoir production (bottomhole and oil production) data in the history matching process. Seismic and production data are complementary in the sense that they have good resolution in space and time, respectively.