In extracting average velocity fields, the choice of different datum planes can lead to different timetodepth conversion results. In the twostep static correction used at present, there are two datum planes to construct the average velocity field and perform the timetodepth conversion: one is the velocity spectrum analyzing datum plane, i.e., the CMP datum plane, and the other is the final seismic datum plane, i.e., the common datum plane. The velocity field and timetodepth conversion were studied on these two different datum planes, and a method was put forward for deriving a smoothed nearsurface plane for timetodepth conversion by averaging all elevations of each receiver and each shot point within the scope of a CMP gathered. A case study shows that this method can provide higher precision velocity field and structure map without using any borehole data than the routine velocity field study method on common datum plane.
李杏莉, 王彦春. 不同基准面上的速度场及时深转换[J]. 物探与化探, 2009, 33(1): 49-53.
LI Xing-Li, WANG Yan-Chun. THE VELOCITY FIELD AND TIMETODEPTH CONVERSION
ON DIFFERENT DATUM PLANES. Geophysical and Geochemical Exploration, 2009, 33(1): 49-53.