Prestack Kirchhoff time migration of 3D coal seismic data from mining zones
Y. Yuan, Y. Gao, L. Bai and Z. Liu
Journal name: Geophysical Prospecting
Issue: Vol 59, No 3, May 2011 pp. 455 - 463
Info: Article, PDF ( 1.25Mb )
Conventional seismic data processing methods based on post-stack time migration have been playing an important role in coal exploration for decades. However, poststack time migration processing often results in low-quality images in complex geological environments. In order to obtain high-quality images, we present a strategy that applies the Kirchhoff prestack time migration (PSTM) method to coal seismic data. In this paper, we describe the implementation of Kirchhoff PSTM to a 3D coal seam. Meanwhile we derive the workflow of 3D Kirchhoff PSTM processing based on coal seismic data. The processing sequence of 3D Kirchhoff PSTM includes two major steps: 1) the estimation of the 3D root-mean-square (RMS) velocity field; 2) Kirchhoff prestack time migration processing. During the construction of a 3D velocity model, dip moveout velocity is served as an initial migration velocity field. We combine 3D Kirchhoff PSTM with the continuous adjustment of a 3D RMS velocity field by the criteria of flattened common reflection point gathers. In comparison with post-stack time migration, the application of 3D Kirchhoff PSTM to coal seismic data produces better images of the coal seam reflections.