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A Successful Implementation of Diving-wave Refraction Tomography for Near-surface Velocity Model Building in East Siberia
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, GeoBaikal 2018, Aug 2018, Volume 2018, p.1 - 5
Abstract
The near-surface of Ignyalinksoe field is characterized by its complex structure. High velocity contrast anomalies related to thrust faults create challenges for seismic data processing and further quantitative and qualitative seismic interpretation. The compressional velocity of the near-surface varies between 1000 and 6000 m/s. It is widely recognized that inability to properly resolve anomalies at the upper part of the initial velocity model can lead to artefacts at later stages of velocity model tomographic updates. These artefacts can then cause poor imaging of the target during depth migration and signal distortion.
Due to the reasons mentioned earlier it was decided to implement Diving-Wave tomography for PSDM velocity model building at the near-surface. This is the first time of application of this technology for the complex conditions of East Siberia. DWTomo is a 3D tomography which can resolve complex high-contrast velocity anomalies.
The obtained image obtained after the Prestack Kirchhoff Depth Migration with DWTomo incorporated at the top of the model shows a dramatic improvement compared to the previous processing. The negative impact on the amplitudes and structure of the target horizon is noticeably minimized.