Simplified Modeling of Turbidite Channel Reservoirs

Abstract

Summary Effective properties can represent fine-scale geologic heterogeneities in simple full-field reservoir models without having to model them explicitly. A comprehensive simulation study tests the sensitivity of dynamic connectivity in turbidite channel reservoirs to a large number of stratigraphic and engineering parameters. Simulations performed using geologically realistic sector models at multiple levels of stratigraphic resolution show that dynamic connectivity is governed by large-scale architectural parameters, such as meander-belt size, net-to-gross ratio, degree of depositional-storey amalgamation, and stratigraphic parameters that describe the shale architecture at multiple scales (e.g., shale-drape coverage and shale-drape frequency of occurrence). We demonstrate how to rapidly generate effective properties at multiple geologic scales, incorporating the effect of channel architecture and reservoir connectivity into simple dynamic models. Use of simple dynamic models in conjunction with effective properties, principally geologically based pseudorelative permeabilities, accelerates the simulation workflow significantly. We show that a statistical distribution of the recovery factor (RF) can be produced within hours instead of days by the combined use of Monte Carlo simulation and a simple dynamic model with effective properties. Recovery factors estimated with our simplified modeling method agree well with observed RF distributions of turbidite channel reservoirs with significant production history.