复杂三维表层模型层析反演与静校正

针对三维地震勘探中的复杂地表问题，本文研究了三维初至波表层模型层析反演及静校正方法。该方法利用了三维地震直达波、回折波、折射波及三者组合的初至波和具有三维空间变速优势的三维层析反演，实现了适应速度任意变化的复杂三维表层模型层析反演，此法对初至的要求是，只需检测首先到达的波的起跳时间，无须解释此波的类型；三维模型正演采用以费马原理为基础的三维网络法射线正演方法；三维层析反演采用带阻尼的最小平方QR分解迭代算法。采用上述措施不仅可提高表层速度模型层析反演的可靠性，为三维地震资料层析静校正提供合理的表层速度模型，而且提高了计算效率，增强了方法的实用性。

Tomographic inversion for 3-D complex near-surface modei and static correction.

In view of complex near-surface issue in 3-D seismic exploration, the paper presented a method for tomographic inversion by using 3-D first-break near-surface modei and for static correction. Using 3-D seismic direct wave,bow tie, refracted wave and first break composed of above the three modes and 3-D tomographic inversion having advantage of 3-D spatially-varying velocity, the method can achieve tomographic inversion in 3-D complex near-surface modei which the velocity can change arbitrarily; the demand of the method on the first break is only detecting the break-time of first-ar-rived wave without interpretation of the wave mode; 3-D network ray-tracing method based on Fermat's principle is adopted in the 3-D forward modeling;the damping least-square QR decomposi-tion iterated algorithm is adopted in 3-D tomographic inversion. Adopted above-mentioned meth-ods can both improve the reliability of tomographic inversion for near-surface velocity model, provide reasonable near-surface velocity modei for tomographic static correction of 3-D seismic data and improve the computational efficiency, increasing the practicality of the method.