准噶尔盆地南缘山地静校正方法探讨

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

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。

The near-surface sur vey and static correction are the key tasks of seismic data pro cessing 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 ba-sic principles,ap plicable conditions and merit and demerit of several conven tional methods for surface structure survey are an a-lyzed.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(EGRM),inte grated with mini-re frac-tion,differential log andτvalues,the method for near-surface structural models is developed,and taking3D seismic of Tugulu mountain area as an example,the effectiveness of the composite modeling is indicated.