库车坳陷高陡构造地区零井源距VSP资料波场分析与识别  

Wave field analysis and identification of zero-offset VSP data in high and steep structures area of Kuqa depression

作　　者：王冲 蔡志东 刘聪伟 吴俊军 WANG Chong;CAI Zhi-dong;LIU Cong-wei;WU Jun-jun(Development and Production Seismic Division,BGP Inc.,CNPC,Hebei Zhuozhou 072750,China;China University of Geoscielwe,Beijing 100083,China)

机构地区：[1]中国石油集团东方地球物理公司新兴物探开发处,河北涿州072750 [2]中国地质大学(北京)地球物理与信息技术学院,北京100083

出　　处：《地球物理学进展》2018年第4期1596-1602,共7页Progress in Geophysics

基　　金：国家十三五重大专项"库车坳陷深层-超深层天然气田开发示范工程"(2016ZX05051)资助

摘　　要：库车坳陷属于高陡构造地区,油气资源丰富,勘探潜力巨大.但是该地区地下构造复杂,断裂发育,地层倾角陡,地震波场复杂,地震成像品质较差是制约库车复杂构造研究的主要因素.零井源距VSP资料波场上转换横波很发育,波场记录上转换横波和纵波同时存在造成该地区地面地震波场相当复杂,影响地面地震资料的成像品质.因此为了避免地面地震资料处理过程中各种波场的相互影响,利用VSP波场信息能防止地面地震资料处理过程中可能出现的"陷阱".本文充分发挥VSP波场信息丰富的特点,通过库车坳陷高陡构造地区零井源距VSP波场正演模拟和实际资料波场分析,准确识别纵波和转换横波波场,并利用有效的波场分离手段分离出VSP纵波波场和VSP转换横波波场.通过VSP纵横波波场与实际地面地震资料对比,能很好地识别出了地面地震资料上的纵波和转换横波波场,为库车坳陷高陡构造地区地面地震资料处理提供参考依据.研究表明:库车坳陷高陡构造地区转换横波在地震纵波成像中影响较大,建议库车坳陷高陡构造地区地面地震处理要加强转换横波的识别与应用,进一步加强井地联合处理攻关研究,获得更可靠、更高品质的纵波资料,同时也能得到更为丰富的转换横波资料.Kuqa depression belongs to high steep structure area,rich in oil and gas resources and great exploration potential.However,the underground structures in this area are complex,faults are developed,the dip angle is steep,the seismic wave field is complex,and the seismic imaging quality is poor. It is the main factor that restricts the study of complex structures in Kuqa. The converted shear wave is very developed in the wave field of the zerooffset VSP data, and the wave field records the simultaneous existence of up converted shear wave and longitudinal wave. The seismic wave field in the area is quite complex and affects the imaging quality of seismic data. Therefore,in order to avoid the interaction of various wave fields during seismic data processing,the VSP wave field information can be used to prevent possible＂traps＂in seismic data processing. This paper gives full play to the rich information of VSP wave field. The zero-offset VSP data in high and steep structures area from VSP wave field forward modeling and wave field analysis of actual data,accurately identify the P-wave and converted wave field, and the use of effective wave field separating means for separating VSP compressional wave and the VSP wave field conversion. By comparing the VSP vertical wave field with the actual seismic data,the P-wave and converted shear wave fields on seismic data can be well recognized,which provides a reference for seismic data processing in high and steep structures area. The study shows that converted waves in high and steep structures contribute greatly to seismic P-wave imaging. We suggest that the high steep structure area of seismic processing to strengthen the recognition and application of converted wave, and further strengthen the combination of VSP and seismic research,to obtain P-wave data more reliable and high quality,but also can get richer data converted wave.

关 键 词：库车坳陷 高陡构造 零井源距VSP 纵波 转换横波 井地联合 

分 类 号：P631[天文地球—地质矿产勘探]