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Traveltime inversion in laterally varying media with a priori information: A versatile tool for the structural interpreter
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, EAGE/SEG Research Workshop 1990, Jul 1990, cp-53-00025
- ISBN: 978-94-6282-136-1
Abstract
Depth-domain images of structures can be obtained by depth migration, but this requires an accurate velocity model, especially in case of laterally varying velocities. Tomography, viewed as the estimation of the velocity model using prestack picked reflection traveltimes and geological a priori information, is a good means to fulfill this requirement. We study a gas prospect in which gas accumulations located in an anticline induce lateral variations in the velocity. From the arrival-times of 6 reflections, tomographic inversion gives a velocity model showing negative velocity anomalies at the top of the anticline. Checking the quality of the model by depth migration leads to refine it by constraining the bright-spots to be horizont al. This is easily done using a priori information.