Quantitative Seismic Interpretation using Rock Physics Templates - case examples from the Zumba field

Abstract

A post drill inversion study was done by Avseth et al. (2016) after the dry well result from Zumba prospect. The AVO inversion failed in a graben setting, caused by a hard carbonate layer and associated refraction just above the target prospect. The new AVO inversion results showed a significant improvement both in AI and Vp/Vs predictions. The objective of this thesis is to improve the understanding of the seismic response for better lithology and fluid prediction and investigate further prospectivity in the Zumba graben with the updated elastic inversion data which are calibrated to the new well. In this study, we utilized Rock Physics Templates (RPTs) for lithology and pore fluid interpretation of well-log data and elastic inversion results. The main procedure consists of two basic steps: (1) selecting the template that is consistent with the well-log data; and (2) applying the user-defined polygon boundaries in the template to classify elastic inversion results. We also generated rock physics attribute (CPEI and PEIL) from RPT(s) that can be used to screen reservoir zone from seismic inversion. The results show that we can potentially distinguish between different types of lithology facies in the study area. We are also able to delineate and predict potential hydrocarbon accumulations and possible remaining prospectivity in the Zumba Graben in the Norwegian Sea.