Application of full-azimuth tomography velocity model building for complex conglomerates in western China

Abstract

The huge thick conglomerates are widely developed in the shallow part of the earth in the southern Junggar basin, the velocity variation of the conglomerates can’t be built correctly by conventional tomographic method based on CIP gathers without azimuthal moveout variations. The velocity model can’t meet the need of the high quality imaging. The full azimuth local angle domain gathers retain not only the moveout variations with incident angle but also the azimuthal moveout variations, so the RMOs of different azimuth can be matched with the ray tracing of different azimuth. Therefore, the velocity update solution is more accurate. In this paper, we demonstrate a full azimuth tomographic velocity model building case in the southern Junggar basin. We concluded that the resolution of the velocity variation has been significantly improved, and the depth migration imaging is more accurate.