Beam Tomography (BT) is a novel high resolution, wide azimuth migration velocity analysis tool using Beam Migration. The high resolution updates are comparable to FWI results, with three orders of magnitude more efficiency. A 2000 sq km velocity model can be updated using 400 CPUs in less than 5 minutes. The Beam Tomography uses Beam Migration to directly output the velocity update matrix with a very high number (2000-10,000) of velocity update values at each (x,y,z) analysis point. This methodology bypasses the time consuming steps required for traditional tomography, including preparing the gathers for semblance analysis, semblance picking and back-projection picks QC. The method enables a very rapid estimation of the depth or time delays along each ray that can be used to produce a high quality alignment of the common-image angle or offset gathers. In addition, Beam Tomography output contains image point azimuth information and this allows the tomographic update to go beyond the current limitation of limited wide azimuth velocity updates. In summary, Beam Tomography allows for faster turnaround time for large 3-D seismic projects and at the same time increases the accuracy of the velocity model by using wide azimuth information that is typically unavailable in traditional tomography.
Online Tech Lunch: High Resolution Beam Tomography for Velocity Model Building – September 23rd, 2020
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