Integration of Geology and Geophysics in AVO Facies Classification

Abstract

Complex geological environments require careful investigation to determine the spatial distribution of various facies. Geophysical AVO signature can bene tuned with information about geological properties. This integration of geology and geophysics through rock physics tools gives us the opportunity to map larger areas from a seismic survey in greater geological detail. Extraction of geological properties from well logs and through simulation gives valuableinformation about what AVO trends to expect and the relationship betweenAVO and geological facies. This was done to create six different facies. A calibration process transformed seismic amplitude values into reflection values of intercept and gradient. The AVO amplitudes were classied based on their Mahalanobis distance from the simulated facies classes. This gave a facies map with good geological resolution that enhanced discrimination of uidand cement levels. The map also showed that the classication managed to assign the right facies at the observed well locations