三维地震区井震资料不符原因及解决方案——以北三台凸起西地2井三维地震区为例

对西地2井三维叠前时间偏移剖面的研究发现，位于构造高部位的钻井，在时间剖面上目的层梧桐沟组t0反而比构造低部位大，这种井震资料不符的现象从古近系底界开始出现。分析认为，出现井震资料不符的主要原因是新生界速度横向上的变化所致。叠前深度偏移处理技术是解决复杂构造正确成像的有效方法。采用Kirchhoff积分法进行叠前深度偏移处理，得到了符合研究区空间变化规律的由南至北逐渐降低的速度模型，使地层的形态得到了正确校正，井间相对关系得以正确恢复，井震资料不符的问题得到了解决。

Reason Analysis and Solution for Log-Seismic Data Discrepancy in 3D Seismic Area: A Case Study of Well Xidi-2 3D Seismic Area in Beisantai Swell,Junggar Basin

The study of 3D prestack time migration profile of Well Xidi?2 indicates that the time domain profile of the Wutonggou formation as a target zone in drilled well with hither structural position has bigger t0 compared with well logging data. Such a log?seismic discrepancy occurs from the bottom of Paleogene in this area. The analysis suggests that the reason for it mainly results from the lateral velocity changes of the Cenozoic here. Prestack depth migration processing technique is an effective approach for precise imaging of complex structures.This paper uses Kirchhoff ingegral method to make prestack depth migration processing, and gets the south?north reducing velocity model for the space variation in this area. Finally, the morphology of formation has been corrected, the relative relationship between wells has been recovered, and the problem of the log?seismic data discrepancy has been resolved