摘要
基于一维连续介质模型假设,无射线追踪层析静校正技术隐式地利用了水平地表回折波的射线传播规律和运动学特性层析反演近地表模型。鄂尔多斯盆地黄土塬地区黄土巨厚,地表起伏剧烈,风化层速度横向上比较稳定,而垂向上呈连续变化,比较符合一维连续介质模型假设。但是由于地表起伏剧烈,水平地表的回折波时距曲线特性不成立,不能直接利用无射线追踪层析静校正技术。本文首先讨论了无射线追踪层析静校正技术的基本原理、算法和适用条件,然后针对黄土塬起伏地表地区,推导出起伏地表连续介质回折波时距曲线方程,并且提出采用微测井、小折射资料时深曲线的多项式拟合、野外单炮初至波时距曲线指数拟合相结合的方法,消除地表起伏对初至波传播时间的影响,然后应用无射线追踪层析静校正技术解决黄土塬起伏地表地区的静校正问题。
Based on the assumption of the 1D continuous medium model,the non ray-tracing tomography static correction technique implicitly utilizes the propagation law and the dynamic characteristics of the horizontal surface turning wave to conduct tomography inversion for the surface model.The loess layer in the Loess Plateau,Ordos Basin is very thick with server relief surface,however lateral velocity change in the weathered layer is relatively stable and the velocity showed a continuous variation in vertical direction,so it matches the assumption of the 1D continuous medium model.Due to its relief surface,the time-distance curve characteristics of the turning wave for the horizontal surface can not be established,so the non ray-tracing tomography static correction technique can not be directly utilized.In this paper the basic fundamental of the non ray-tracing tomography static correction technique,its algorithm and suitable conditions were firstly discussed,then regarding the relief surface in the Loess Plateau,the time-distance curve equation of the relief surface in the continuous medium was derived,by integration of the micro-logging method,the polynomial fitting for time-depth curve of the shallow refraction data,and the first arrival time-distance curve exponential fitting for the field single shot,the influence of the relief surface to the first arrival propagation time was removed,then by application of the non ray-tracing tomography static correction technique the static correction problem in the Loess Plateau was successfully solved.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2010年第A01期94-100,239+251,共7页
Oil Geophysical Prospecting
基金
国家973项目(2007CB209604)资助
