基于初至残差的最小二乘法高频静校正技术及应用

Least squares high-frequency static technology and application based on residual first-break time

折射静校正和层析静校正是利用初至时间反演近地表速度模型,解决复杂山地地区的低频静校正问题,由于受偏移距范围、迭代次数和反演精度等因素的影响,由反演模型求解的静校正量残留高频静校正量,影响地震资料的成像质量。针对这个问题,这里提出了基于初至残差的最小二乘法高频静校正技术。假设初至残差就是炮点和检波点高频静校正量,通过最小二乘法构建方程,采用矩阵迭代法求解即可获得炮点和检波点高频静校正量。实际资料的应用结果表明,该方法原理可行、计算稳定快速,可以在折射法或层析法静校正的基础上显著改善地震资料的成像质量。

The low-frequency statics problem in complex mountainous area can be solved by refraction static and tomography static methods,which inverse the near surface velocity model based on first-break time.But the image quality of complex geologic structures is affected by inaccurate statics that still has the high-frequency statics on account of the influences of offset range,iteration times,inversion precision.Aiming at this problem,least squares high-frequency static technology based on residual first-break times was proposed in this paper.The residual of first-break times was considered as high-frequency statics of shots and receivers in this study,which can be solved through the matrix iteration method based on least squares equation.Application results of real data show that the method is feasible and stable,at the same time,the imaging quality of seismic data can be improved significantly based on refraction static method or tomography static method.