AVO Modelling of the South-East Niger Delta, Nigeria

Abstract

Amplitude Versus Offset (AVO) modelling was carried out using pre-stack seismic and well-log data in the southeast Coastal Swamp of Niger Delta. The results of the work demonstrated that seismic pres-stack and well-log data provided valuable information in modelling a reservoir and other important intervals in wells. Amplitude-Versus-Angle (AVA)/ Amplitude-Versus-Offset (AVO) extracted from pre-stack seismic data identified gas sand of AVO Class 3 type. Sandshale lithology is deduced, with sandstone volume decreasing with increasing depth, while shale volume increases with depth. Porosity and permeability showed decreasing trend with depth for both sandstone and shale units. Velocity, GR (API), Poisson's ratio, V p /V s and density increase with increasing depth. Compressional-velocity V p and shear-wave V s are linearly related, and mudrock line equation is established for the study area: V p =0.807Vs+1.600. The results of this work can be used as an Exploration tool for the identification or evaluation of prospective areas, locations and also for feasibility studies during an appraisal activity.