Lithology Estimation at the Edvard Grieg Field Using Wave-Equation Based Seismic AVO Inversion
P.E. Dhelie, V. Danielsen, K.R. Straith, A.O. Ndingwan, A. Droujinina, P. Doulgeris, D. Gisolf, P. Haffinger, M. Zhang and A. Mannini
Event name: 81st EAGE Conference and Exhibition 2019
Session: Dynamic Reservoir Characterization and Modelling I (Joint EAGE/SPE)
Publication date: 03 June 2019
Info: Extended abstract, PDF ( 817.84Kb )
Price: € 20
Conventional linearized inversion techniques tend to be driven by a-priori models as well as interpreted facies. This often leads to predetermined and biased inversion results. The relatively new wave-equation based AVO inversion method (WEB-AVO) overcomes this primarily by starting from a very simple background model, combined with forward modeling using the full wave-equation, to iteratively build a reservoir property model. This will represent the best fit between the modelled data in the slowness domain and the actual image gathers (from the normal seismic processing) converted to slowness, while obeying the full elastic wave-equation. A thorough rock-physics analysis using well logs was performed to derive lithology facies from the inverted parameters κ (compressibility) and M (shear compliance). A full 3D lithology cube has been compared to lithology logs from several production wells and results are of high correlation. The method demonstrates nicely that the Edvard Grieg field has three very distinct reservoir facies and the distribution of these follow the understanding obtained from drilling more than 15 wells across the field over the last decade.