利用层析反演技术解决山地复杂区静校正问题

Solving the static correction problem in mountain complex block using tomographic inversion

1. 东方地球物理公司采集技术支持部,河北涿州 072751;2. 玉门油田分公司,甘肃玉门 735200

The data acquisition technical supporting department of CNPC Geophysical Prospecting Bureau, Zhuozhou 072751, China

山地和山前带地区表层结构复杂,利用表层调查模型和初至折射静校正方法不能解决低、降速带巨厚区的静校正问题,为此进行了层析反演静校正技术的研究。给出了层析反演静校正技术的基本原理;讨论了初始速度模型的建立、模型空间范围的确定、模型底界和替换速度的选取等;在网格的确定上提出了在保证迭代收敛的前提下应尽量的小,以最大程度地解决长波长静校正问题的思路。采用层析反演静校正方法很好地解决了山前带地区长波长静校正问题,提高了山地地震资料的叠加效果。

Faced to the problem of static correction caused by complex near-surface structures in mountain and mountain-front areas, we did some researches on the application of tomographic static correction. The paper summed up systematically the major techniques, such as the build-up of initial velocity model, selection of grids and analysis and interpretation of the final near surface model etc. , and presented a new idea about selection of grids and interpretation of model. This method was successfully applied in many mountain-front seismic exploration projects in recent years, and well solved the problem of long-wavelength static corrections existed in these areas and improved stack effects, the structural accuracy and imaging quality of seismic data in mountain area as well.