哈拉湖地区低频可控震源天然气水合物地球物理响应特征研究  

Geophysical response characteristics of gas hydrate in Har Hu region based on low-frequency vibroseis data

作　　者：田玉昆[1] 李桂林[1] 刘晖[1] 祝有海[1] 马彦彦[1] 李娟[1] 周惠[1] 王德润 王林 TIAN Yu-Kun LI Gui-Lin LIU Hui ZHU You-Hai MA Yan-Yan LI Juan ZHOU Hui WANG De-Run WANG Lin(The Key Laboratory of Unconventional Petroleum Geology, CGS, Beijing 100029, China Tuha Division, BGP Inc., CNPC, Hami Xinjiang 839009, China BGP International ,CNPC, Zhuozhou Hebei 072750, China)

机构地区：[1]中国地质调查局非常规油气地质重点实验室,北京100029 [2]中国石油集团东方地球物理公司吐哈物探处,新疆哈密839009 [3]中国石油集团东方地球物理公司国际勘探事业部,河北涿州072750

出　　处：《地球物理学报》2016年第11期4287-4296,共10页Chinese Journal of Geophysics

基　　金：地质矿产调查评价专项(DD20160181;12120115006601);天然气水合物资源勘查与试采工程(GZH201400302);国家自然科学基金(41202076)联合资助

摘　　要：我国陆域天然气水合物主要分布于青藏高原和漠河地区.由于永久冻土层的存在,地震勘探很难获得高品质的资料,给天然气水合物勘探带来了诸多困难.为解决冻土层对地震信号的衰减问题,在哈拉湖地区采用低频可控震源进行地震资料采集试验,通过提高覆盖次数,获得了较高信噪比的地震资料.在高质量地震资料基础上,进行精细速度分析,获得了较准确的叠加速度谱资料;然后以层速度剖面为基础建立正演模型,开展天然气水合物地震正演模拟研究;最后利用叠后偏移地震数据进行地震属性分析.通过正演模拟和地震属性综合研究,总结了天然气水合物的地球物理响应特征,速度突变和空白反射带可作为哈拉湖地区陆域天然气水合物识别的敏感因素.In China,terrestrial gas hydrate is mainly distributed in Qinghai-Tibet Plateau and Mohe County regions.Because of the existence of permafrost,it is difficult to obtain high quality data by seismic exploration,which brings many difficulties to the gas hydrate exploration.In order to solve the problem of attenuation of seismic signal by frozen soil,we used the lowfrequency vibroseis as the means to do seismic data acquisition test,and obtained higher signal tonoise ratio seismic data by increasing the folds.Based on the high quality seismic data,fine velocity analysis is carried out to obtain the accurate stack velocity spectrum data.And then forward modeling is established on the basis of interval velocity,seismic forward research of gas hydrate is developed.Finally,seismic attribute analysis is carried out on the post stack migration profile.The geophysical response characteristics of natural gas hydrate are summarized through the comprehensive study of the forward and the post stack seismic attributes.The mutational speed and the blank reflection zone can be used as the sensitive factors to identify the terrestrial gas hydrate in Har Hu region.

关 键 词：天然气水合物 低频可控震源 冻土区 纵波速度 地震属性 哈拉湖地区 

分 类 号：P631[天文地球—地质矿产勘探]