基于二分法的地震波初至自动拾取算法  

The algorithm for automatic first-breaks picking on seismic traces based on Dichotomy

作　　者：陈金焕[1] 曹永生[1] 孙成龙[1] 许自龙[1] 裴宇翀 毕进娜 陈海洋[1] 

机构地区：[1]中国石油化工股份有限公司石油物探技术研究院,南京211103

出　　处：《地球物理学进展》2015年第2期688-694,共7页Progress in Geophysics

摘　　要：初至拾取是地震资料处理中最基本的环节,随着地震资料的增多,自动拾取算法越来越重要,它将严重的影响地震资料处理的速度和效率.本文给出一种新的初至自动拾取算法,它根据参考初至(理论估计的初至),利用二分法和改进的能量比方法检测初至并去除不准确点,通过微调获取波峰、波谷、起跳点三种不同的初至类型.通过对不同信噪比的实际地震数据进行测试,本算法具有快速准确的特点.随着资料信噪比的降低,本算法未能完全解决拾取准确度降低的问题.然而通过适当调整算法的参数,本算法的结果比商用软件OMEGA的初至自动拾取效果要好.First break picking is the most basic part in seismic data processing. The automatic picking algorithm of first arrivals is becoming more and more important as the increasing data in seismic exploration, and it will affect the speed and efficiency of the whole seismic data processing seriously. On the one hand, the time of the first breaks is used in velocity measurements ranging from elementary refraction profiling to the most sophisticated tomographic inversions of first arrivals. On the other hand, the artificial first break picking is very labor-intensive and time-consuming. For these facts, based on the first-breaks available for reference （or theoretical estimated first-breaks）, a new algorithm is proposed for the automatic picking of first breaks, which includes three different picking forms--peak, trough, takeoff. The picking techniques are based on the facts that the dichotomy can be used to determine the picking scopes rapidly and the transition between noise and noise plus signal can be automatically identified by detecting rapid changes in improved energy ratio. A skill to remove the inaccurate first breaks depends on the available for reference as mentioned before. Furthermore, the algorithm has been tested on real data sets with varying S/N ratios. As we expected, the picking results were got quickly and accurately. Meanwhile, this algorithm cannot solve the problem that the picking results are not so good with the low S/N ratios. However, with an appropriate tuning of its parameters, this algorithm proved more accurate than commercial software OMEGA.

关 键 词：初至 自动拾取 二分法 商用软件OMEGA 

分 类 号：P631[天文地球—地质矿产勘探]