FWI-guided Q Tomography for Imaging in the Presence of Complex Gas Clouds
J. Zhou, X. Wu, K. Teng, Y. Xie, F. Lefeuvre, I. Anstey and L. Sirgue
Event name: 76th EAGE Conference and Exhibition 2014
Session: Multi-parameter FWI
Publication date: 16 June 2014
Info: Extended abstract, PDF ( 929.33Kb )
Price: € 20
The presence of gas clouds has long been recognized as a significant problem in the seismic data processing. To compensate for the gas absorption effect in the Q-PSDM migration, both the geometry and the Q values within these anomalous attenuation regions need to be accurately estimated. In recent years, Ray-based Q tomography has been successfully applied to field data to estimate the anomalous Q model. However, when the distribution of the gas charged sand bodies gets more complex, Q tomography itself often fails to provide necessary resolution to generate a geologically plausible absorption model. Joint inversion for velocity and Q with visco-acoustic full waveform inversion has attracted a lot of interests from the industry; however, it remains a very challenging topic as the joint inversion for both VP and Q is an ill-posed problem, as they are coupled. In this paper, we propose a new approach which uses the highly detailed velocity information from the 3D frequency domain FWI to guide the Q tomography inversion. We demonstrate with a production example offshore Malaysia that our method can effectively reconstruct the Q model and improve the seismic imaging in the presence of complex gas clouds.