Acoustic and Elastic Impedance Models of Gullfaks Field by Post-Stack Seismic Inversion

Abstract

Gullfaks is one of the major hydrocarbon producing fields in the Norwegian continental shelf. This field has a quite complex geology which makes routine seismic interpretation a challenging task for understanding the reservoir properties such as lithology and fluid content. Post-stack seismic inversion has proven to be a reliable tool for detailed understanding of the reservoir especially for lithological identification. In this study, post-stack seismic inversion method was used on acoustic and elastic impedance models to build an inverted impedance model. For this purpose, three horizons were interpreted from the reservoir zone to determine geological inputs for the model. Check shot survey was used to build synthetic traces which were then tied to the real seismic data. Two initial impedance models were then build i.e. acoustic initial impedance model and elastic initial model at zero degree angles. Four different inversion algorithms were applied to invert the initial models and their results were compared. The inverted models showed high vertical resolution with high signal to noise ratio, giving an excellent visualization of the reservoir zone.