Estimation of net-pay thickness, using seismic reflectivity and band-limited impedance approaches, Central Nile Delta, Egypt

Abstract

It is well-known that, the seismic amplitude scaling techniques are used to remove the tuning effect on seismic amplitude maps. Nonetheless, they are useful to predict the net-pay thickness in low impedance hydrocarbon-bearing sands. The aim of this paper is to address the prediction of the net-pay from seismic reflectivity compared to the band-limited impedance inversion techniques. The first step for the net-pay prediction from reflectivity consists in the plotting the amplitude extracted between top and bottom of the reservoir against the apparent thickness. Another approach to predict net-pay thickness is through colored inversion. Connolly and co-authors utilized the band-limited impedance of the colored inversion data rather than the conventional seismic amplitude. Connolly's method uses the average band-limited impedance and the apparent thickness values extracted between the zero-crossing picks. The results show that the Connolly's band-limited impedance technique shown a significant improvement over Brown's reflectivity-based techniques.