基于OBS的正演模拟与初至识别研究
Forward modeling based on OBS and first break recognition research
潘军 1刘保华 2华清峰 3刘晨光 3李西双 3裴彦良3
作者信息
- 1. 中国海洋大学海洋地球科学学院,青岛266100;国家海洋局第一海洋研究所,青岛266061
- 2. 国家深海基地管理中心,青岛266061
- 3. 国家海洋局第一海洋研究所,青岛266061
- 折叠
摘要
在深部壳幔结构研究中,采用OBS接收到深部构造的折射、反射信号并通过层析成像反演地下结构是当前最为有效的方法.初至识别则是层析成像处理OBS资料最重要的工作之一,而基于OBS的正演模拟对于初至的正确识别具有重要的指导作用.本文利用二维声波波动方程实现了基于OBS的数值模拟,获得了水平层状、倾斜模型条件下的OBS共接收点道集.通过研究OBS共接收点道集反射波、折射波在不同地质模型下的规律,对OBS初至识别方法进行总结,并在实际资料处理中加以应用.结果表明,利用OBS共接收点道集的多图对比可以较简便地实现初至识别,其中水平层状地质模型初至必然呈现对称性,而倾斜模型的初至则需要综合考虑反射波、折射波的规律进行判断.
Abstract
In deep crust and mantle research, it is the main method to use OBS (ocean bottom seismometer) to receive refraction and reflection signal from deep structure, and then inverse the depth and velocity of deep structure by tomography. First break recognition is one of the most important steps in OBS tomography which directly determines whether you can get the correct structure. OBS simulation is an effective method which can provide guidance for first break recognition. This paper accomplished numerical simulation based on OBS using 2D sound wave equation according to the requirement of first break recognition, achieved common receiver gathers based on OBS with horizontal layered and dipped geologic model. By analyzing the reflection and refraction events in the OBS gathers of the two different models, we found some basic principle of first break recognition. The principle was also useful in practical OBS data processing which the data came from the OBS survey in Bohai Sea of China in August 2011. The research shows that the comparison among multi-OBS common receiver gathers is a simple way for first break recognition. First break presents symmetry if the geology model consists of horizontal layered medium and it is easy to recognize. It is more complicatod that first break recognition should use reflection and refraction events whenencountering dipped geology model.
关键词
OBS/正演模拟/有限差分/并行运算/初至Key words
OBS/simulation/finite difference method/parallel algorithm/first break引用本文复制引用
基金项目
863计划重点项目"(2009AA093401)
自然科学基金重点课题(90814011)
中央级公益性科研院所基本科研业务费专项资金项目(2010G11)
出版年
2012
NETL
NSTL
维普
万方数据