Integration of acoustic impedance into genetic reservoir characterisation: a synthetic model study

Abstract

Whilst the adequate characterisation of reservoir heterogeneity is an acknowledged problem in the petroleum industry, surprisingly little use is made of seismic data to predict lithofacies and porosity in reservoir regions without adequate well control. Previous attempts at using seismic attributes to predict lithofacies and porosity are reviewed and a new technique based on simultaneous use of seismic and well data is proposed. This new procedure is based on a two-step collocated cokriging method. The first step simulates lithofacies architecture and is followed by the estimation of porosity for each lithofacies group. Model studies show that this approach results in an improved description of reservoir lithofacies architecture and porosity variation. Moreover, the proposed technique is consistent with concepts of genetic reservoir characterisation, which aims to characterise the reservoir in terms of lithological flow units. The cokriging results are shown to be more reliable than those obtained using older and more established techniques.