Pre-salt Carbonate Characterisation Using 2D Dual-Sensor Data and Rock Physics - Kwanza Basin Case Study

Abstract

The giant sub-salt discoveries from the conjugate Brazilian margin give encouraging support for analogous hydrocarbon potential offshore Angola. The challenge is to image the deep geology beneath complex salt geometries to confidently predict reservoir properties and distribution. Pre-stack relative inversion was performed on dual-sensor broadband 2D data from the Kwanza Basin and was correlated to the pre-salt carbonate succession in a discovery well. Well log analysis and rock physics confirm what is observed on the relative acoustic impedance volume. Two distinct types of carbonates with significantly different reservoir properties can be discriminated on the inversion volumes. This result demonstrates that the additional bandwidth from acquired deep-tow broadband seismic can reliably map reservoir properties even in deep challenging geological environments.