多井VSP资料在复杂地表区静校正处理中的应用

Application of multi-well VSP data in statics correction in complex surface area

新疆YKB地区地形起伏大、浅层速度纵横向变化大,用恒定替换速度静校正方法不能解决该区的静校正问题,构造圈闭难以落实。首先分析了恒定替换速度高程静校正、折射静校正和层析折射静校正等方法存在的问题,讨论了替换速度不准确对资料处理带来的一系列影响;在此基础上,提出了多井VSP联合控制替换速度的静校正处理技术,利用实测的初至时间对静校正量进行约束,以控制静校正量的长波长趋势,提高静校正量的可靠性。利用实际资料对比分析了多井VSP联合控制替换速度与恒定替换速度高程静校正方法的处理效果,结果表明,前者比后者能更有效地提高构造的可靠性和剖面的品质。

The terrain of YKB area fluctuates greatly,and the velocity of shallow layers has big lateral and vertical changes.So constant re- placement velocity statics can not solve the static problem in this area and the structural trap is hard to be ascertained.Firstly,the problems were analyzed,mainly about the constant replacement velocity altitude statics,refraction statics and tomography refrac- tion statics.The effect of inaccurate replacement velocity on data processing was discussed.On this basis,multi-well VSP jointly controlling replacement velocity static method was proposed.In the method,the measured first break restricts the statics to control its long wavelength tendency and improve the reliability of statics. Actual data was used to analyze the processing results by multi- well VSP jointly controlling replacement velocity and constant re- placement velocity elevation statics,which shows that the former method can more effectively improve the reliability of structures and quality of profiles than the later.