Pre-stack (AVO) and post-stack inversion of the Hussar low frequency seismic data

Abdul-Nassir Saeed, Gary F. Margrave, Laurence R. Lines

Post-stack and pre-stack (AVO) inversion were performed for the Hussar data to study the role of using very low frequencies seismic data and initial background models on seismic inversion. Another objective is to investigate the accuracy of the resulting acoustic and elastic properties from the inversion.

Seismic data conditioning applied to the common image gathers has improved the signal to noise ratio considerably, and enhanced angle gathers / stacks. These enhancements have facilitated extraction of source wavelets for different angle stacks. The lengths of the angle-dependant wavelets were chosen to be long enough to ensure consistent matching of source and seismic spectrums at the low-cut end of frequency band limit. The experiments proved that inverting of very low frequency seismic data is feasible and reduces the residual error between measured and inverted attributes.

The inverted elastic attributes managed to discriminate different lithologic layers. The resultant inverted sections resolved the lateral extension of the Glauconitic sand, hard shale of Ostracod, Ellerslie formations and other geological markers very well.