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Virtual Shear-Wave Source Delivers a Reliable S-Wave Velocity Model for VSP Imaging
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 81st EAGE Conference and Exhibition 2019, Jun 2019, Volume 2019, p.1 - 5
Abstract
Land walkaway VSP data acquired with vibroseis data contains abundant amounts of converted waves. Their imaging requires an accurate shear-wave velocity model that is often not available. Here, we apply seismic interferometry to create a virtual shear-wave checkshot with first arrivals representing the direct downgoing shear wave along the borehole. Testing on a field data example demonstrates the ability of the redatuming approach to reconstruct accurate virtual gathers and deliver reliable shear-wave velocity from first-break time picks. Using the retrieved shear-wave velocity profile, the mode-converted VSP field data were migrated to obtain a reliable subsurface image consistent with the image obtained from PP data.