Heterogeneity in a Complex Turbiditic Reservoir: Impact on Field Development

Abstract

ABSTRACT In a previous paper [1], a geological/geostatistical methodology has been presented to model heterogeneity in a complex turbiditic formation. The methodology is based on geostatistical conditional simulation techniques that allow building 3D models of geological heterogeneity. The next step consists in translating such stochastic models of heterogeneity into models of flow properties for reservoir simulations. The present paper describes the approach that has been followed to achieve that goal. It includes two steps: a first one, to translate the fine grid geological models of heterogeneity generated in [1] into fine grid petrophysical models,a second one, to upscale the fine grid petrophysical models into coarser grids of effective flow parameters for full-field simulations. The procedure requires precise methods for averaging absolute and relative permeabilities. A new technique for averaging relative permeabilities and capillary pressures is presented. The procedure is validated by the available dynamical data (well tests and a 25 years production history). The integrated geological-geostatistical-upscaling strategy described in [1] and in the present paper is shown to be particularly useful to reservoir history matching and monitoring, as well as to evaluate uncertainties on reservoir performances in undrilled areas of the field.