三维复杂界面炮集P波反射时距特征  

P-wave reflection traveltime characteristic of shotgather from 3D complex structure

作　　者：司洁戈 郝重涛[1] 姚陈[1] 

机构地区：[1]中国地震局地质研究所,地震动力学国家重点实验室,北京100029

出　　处：《地球物理学进展》2016年第1期310-317,共8页Progress in Geophysics

基　　金：国家自然科学基金(41174045);地震动力学国家重点实验室开放基金(LED2011B02)共同资助

摘　　要：近年来,由于勘探区域构造的逐渐复杂化,要求我们对复杂界面反射的时距特征有更进一步认识.本文在已有对复杂界面研究的基础上,结合实际3D复杂地质构造特征,对复杂条件做了两个限定:一是反射界面有界,二是复杂界面有多个不同性质界面组合而成.在这两条限定条件下,从界面反射点出发,进行炮集P波反射时距特征研究.结果表明,复杂界面反射会生产多条时距曲线,反射时距特征随测线方位的变化而变化,不同方位的时距对应的三维反射路径、反射点范围、反射点位置以及界面特征不同.其次时距曲线之间存在着比较复杂的位置关系,包括交叉、断续和无信号道等特征,这些复杂特征与组合模型中倾斜界面的倾向、倾角、模型范围和深度有关.最后对复杂模型的理论数值分析得出了反射点范围与接收点范围的对应关系,并理论证明了复杂条件下部分反射特征以及反射盲区的存在,这与实际三维地震勘探相符合.此研究有助于实际生产的观测设计及数据处理解释,对于提高三维复杂构造反射界面的认识具有理论意义.In recent years, regional structure of 3D seismic exploration is increasingly complicating, and demanding more accurate seismic imaging. So the research of forward simulation is conducted in this paper based on the CRP and complex model made of different kinds of interface. The result shows that the single shot record contains several traveltime curves form different parts of complex interface, and traveltime curves are different with the change of azimuth. A conclusion can be made that the difference of travel time curves between the line parallel to the dip direction of interface and the line perpendicular to the dip direction of interface is maximum. What ＇ s more, the travel time curves with characteristics of curves crossing and no-signal traces are change gradually with the offset changing in different survey lines,and all the characteristics are attributed to the factors of the dip,dip angle,range and the deep of the model. The method of elliptic timedistance can explain curves crossing perfectly. Besides,there is a revolutionary conclusion that the blind area exists in complex structure. In a word, the research not only can deepen understanding about the underground structures,but also beneficial to the survey design and data procession.

关 键 词：3D复杂界面 界面有限 时距特征 反射路径 

分 类 号：P631[天文地球—地质矿产勘探]