FWI as an effective solution for land near-surface model building into the area with complex geological settings: Eastern Siberia case study
D. Tverdokhlebov, V. Korobkin, A. Kleshnin, E. Kashirina, E. Danko, V. Zaravnyaev and R. Melnikov
Journal name: First Break
Issue: Vol 37, No 10, October 2019 pp. 39 - 47
Info: Article, PDF ( 2.63Mb )
Seismic imaging in the Eastern Siberia region is challenging due to the presence of complex overburden anomalies such as magmatic intrusions and thrusts in the suprasalt complex leading to significant vertical and lateral property variations of high-velocity halite-carbonate geological sections with multiple velocity inversions, complex shallow stratigraphy and substantial topography. Such geological settings create amplitude dimming and wipeouts in the images and cause structural distortions at the reservoir level. We applied full-waveform inversion (FWI) technology to overcome limitations of the conventional workflow and to support the exploration programme. The primary output of FWI is a high-resolution subsurface velocity model, which can be used as an attribute to improve interpretation of the overburden sediments, to identify shallow hazards, to derisk exploration prospects and to optimize well placement. We tested FWI on a conventional 3D land data set to create a near-surface velocity model. Detailed subsurface models generated with FWI provided an accurate description of the overburden and helped us to investigate shallow geological environments. Predrill predictions using the FWI velocity volume showed excellent agreement with well measurements and made it possible to recommend the technology for inclusion in the processing flow.