Application Of Tomography Static Correction Technique Without Ray Tracing In The Seismic Data Processing Of The Complicated Mountains Region In Sichuan

With the development of seismic exploration, the exploration work in China gradually turned to the mountain region, desert, gobi and loess tableland areas. There are large degrees surface and variable lateral velocity in complex area, which cause difficulties for statics correction and seriously affect the quality of seismic data imaging.To address these problems, some typical statics correction methods were analyzed comprehensively. Tomography correction without ray tracing and each categories of factors which impact this method were studied deeply. Meanwhile, the advantages and disadvantages of this approach and its applicable conditions were summarized. The main works of this dissertation contained the following aspects:1.This thesis was based on the seismic data acquired in a region of Sichuan basin. According to geological conditions and the character of seismic data, the region statics correction is serious and the problem distribution at the northwest and the southeast are different.2. To handle the statics correction problems of this project, conventional statics correction methods such as datum statics correction and ray-tracing tomography statics correction were used. The results of imaging were not very well.3. Tomography correction without ray tracing was applied to this project. After analyzing the influence of primary parameters, the velocity model was derived and statics correction was calculated.Corresponding to conventional methods, the quality of shot gather was improved, the quality of stacking section was overcome greatly. Especially in the northwest complicated mountain, the extent of quality of continuity and smoothness of the phase axis was obviously better than the southeast. In conclusion, non-ray-tracing tomography statics correction is superior to other methods at complicated areas.