摘要
在地形起伏剧烈地区,传统的通过静校正把炮点、检波点校正到水平基准面上进行速度分析,误差较大。可以利用双平方根方程计算反射波旅行时,在弯曲地表上直接进行速度分析,从而避免常规静校正中大的时移量对速度分析精度的影响。但是该方法没有考虑炮点与检波点之间的巨大高差引起反射点的发散,也没有讨论地下反射界面倾斜的情况。为此,推导了地表弯曲、地下反射界面水平或倾斜、介质均匀情况下反射波时距曲线方程的精确表达式,并给出了与不同t0含义所对应的基于CMP道集进行速度分析所采用的反射波旅行时的近似计算方程,并利用理论模型数据进行了试算。
In rugged topography area, traditional static methods result in intolerant errors in velocity analysis. Graziella used double square root equation to compute travel times of reflections from rugged topography, which avoids partly the unexpected effect of large statics on velocity analysis. However, this method did not take into account the reflection scattering caused by huge elevation differences between source and receiver locations, and oblique reflectors. This paper deduced the time-distance curve equations of horizontal and oblique reflectors in homogeneous medium with rugged topography, and the approximate travel-time equations for CMP gather based velocity analysis. The correctness of the method was tested with theoretical data.
出处
《勘探地球物理进展》
2007年第5期352-355,共4页
Progress in Exploration Geophysics
基金
复杂地表与复杂地下地震勘探关键技术研究(P05059)
关键词
弯曲地表
时距曲线方程
速度分析
rugged topography
time-distance curve
stacking velocity analysis
