三维地震资料观测系统设计中的关键参数  

The Key Parameters in 3-D Seismic Data Observation System

作　　者：孟美辰[1,2] 程冰洁[2] 

机构地区：[1]中国地质大学(北京)地球物理与信息技术学院,北京100083 [2]成都理工大学"油气藏地质及开发工程"国家重点实验室,成都610059

出　　处：《科学技术与工程》2014年第36期6-11,共6页Science Technology and Engineering

基　　金：国家自然科学基金青年基金(41204071);国家自然科学基金联合基金(U1262206);国家高技术研究发展计划(863计划)课题(2013AA064201);四川省科技计划应用基础研究计划(2013JY0060)资助

摘　　要：地下复杂地质构造的地震成像目前仍然是一项具有挑战性的技术。野外采集阶段是获得高品质地震成像的一个关键阶段,而主要的采集参数设计得是否合理,在很大程度上决定了地震资料采集观测系统质量的好坏。其中,三维地震资料观测系统设计中的关键参数主要包括:横向分辨率、纵向分辨率、采样间隔、道间距、最大炮检距、面元尺寸、覆盖次数、炸药量、偏移孔径等。四川盆地龙门山中段地区是重要的油气勘探领域,但该地区由于地下地质构造复杂,地形起伏剧烈,部分构造受损,激发、接收条件较差,勘探难度很大,前期勘探的地震资料信噪比较差。因此,对于该地区的高分辨率地震资料采集是一个巨大的挑战。基于四川盆地龙门山中段某探区的地质、地球物理及测井资料,构建了与实际目标储层近似的地质-地球物理模型,获得了自激自收的地震波场记录,模拟结果与前期勘探获得的地震资料较好地吻合,从而验证了所构建的地球物理模型的合理性及适用性。以高分辨率、高信噪比地震资料采集为目标,针对目标探区的地质情况,对三维地震资料采集中的关键参数进行分析和论证。研究结果表明,较小的道间距、较小的面元、较高的覆盖次数、近似勘探目标埋深的最大炮检距是得到高品质地震资料的关键。因此,三维地震资料采集观测系统设计中的关键参数的论证及优选,能从根本上改变地震资料的分辨率,从而为后续勘探中的复杂地质体高精度成像奠定良好的数据基础。Seismic imaging in the underground of complex geological structure is currently one of the most challenging techniques.To obtain a high-quality seismic imaging,the acquisition parameters need to be selected carefully during the acquisition stage,one of the most important stages of seismic imaging.The key parameters of 3-D seismic data observation system design include horizontal and vertical resolution,sampling interval,channel spacing,maximum offset,bin size,multiplicity,the amount of explosive,migration aperture,etc.The central of Longmen Mountain in Sichuan Basin is an important area,which succeed oil and gas exploration.However,it is a very difficult task for high-precision seismic exploration due to the complex underground geological structure,dramatic topography,partially damaged structure,poorly conditions in excitation and reception,difficult exploration,poor seismic data＇ s SNR of early exploration.Based on geological,geophysical and logging data of the central of Longmen Mountain in Sichuan Basin,geological-geophysical models are builded approximating the real target reservoir.It uses the resumption of self-excited forward modeling approach to obtain a theoretical model＇ s wave field records.The result of forward modeling is supported by the previous seismic data,thus confirming the correctness and application of the constructed geophysical model.For the purpose of acquisiting high resolution of seismic data,the general rules of selecting the key parameters of 3-D seismic data acquisition include using smaller channel spacing,smaller bin,multiple coverage,and approximating the depth of exploration targets with maximum offset.It is crucial to use the best acquisition parameters in order to improve the resolution which could lead to a high SNR and highresolution seismic data.

关 键 词：三维地震资料 采集参数 观测系统 正演模拟 关键参数 

分 类 号：P631.422[天文地球—地质矿产勘探]