准噶尔盆地南缘山地静校正方法探讨

准噶尔盆地南缘地形、低降速带速度和厚度变化剧烈,高速层顶界面起伏不平,做好表层调查和静校正工作是地震勘探资料处理的关键。分析了常用的几种调查表层结构方法的基本原理、适用条件和优缺点,考虑到工区内地形和低降速带厚度变化特别巨大,提出南缘工区采用联合调查的方法调查表层地质结构,以绿山折射静校正初至折射法(以下简称EGRM)为基础,综合小折射、微测井和τ值等资料,综合建立近地表结构模型的方法。

Discussion of Static Correction Approaches for Mountains in Southern Margin of Junggar Basin

The near-surface survey and static correction are the key tasks of seismic data processing for mountain landform, varied low-velocity zone and thickness as well as relief top interface of high-velocity layer in southern margin of Junggar basin. The basic principles, applicable conditions and merit and demerit of several conventional methods for surface structure survey are analyzed. In light of extremely varied landform and low-velocity zone thickness in the studied area, joint survey of surface geological structures is proposed and adopted. On the basis of extended generalized reciprocal method (EGR4), integrated with mini-refraction, differential log and ! values, the method for near-surface structural models is developed, and taking 3D seismic of Tugulu mountain area an example, the effectiveness of the composite modeling is indicated.