一种新的平均速度提取方法及其应用

A new method of average velocity extraction and its application

西北石油局规划设计研究院,乌鲁木齐830011

Institute of Planning and Design, Northwest Petroleum Bureau, Urumqi 830011

在塔里木盆地北部雅克拉地区, 用地震资料常规解释法提取的界面平均速度规律性差, 闭合差和闭合差的约方差较大, 在对界面平均速度编辑平滑的过程中加入了较多的人工干预, 使得提取的界面平均速度和时深转换的构造深度精度低。针对上述问题, 我们提出了一种新的界面平均速度提取方法, 选择一种拟合函数对叠加速度一时间对进行拟合；统计分析出拟合系数闭合差中的系统部分并对其进行校正, 实现对叠加速度闭合差的校正；依据积分形式的DIX公式和经过闭合差校正后的拟合函数, 通过变换得到界面平均速度和界面深度与界面反射时间之间的函数关系。应用效果表明, 本方法具有精度高、效率高的特点。

In the Yakela area of northern Tarim Basin. the interface average velocity extracted byconventional seismic data interpretation has a bad regularity and large misties. The personal factoris also large in editing and smoothing the interface average velocity. This results in a low precisionfor the velocity and the depth obtained. In view of the above problems this paper presents a newmethod. First, a fitting function is chosen to fit the stacking velocity and time pairs. Then weanalyze statistically the systematic error of fitting coefficient misties and correct it. Finally thefitting function and the integral-type Dix formula are used to get the functional relation betweenthe interface average velocity and the reflection time as well as that between the interface depthand the reflection time. The method is of high precision and efficiency as shown by applicationres nits.