上覆水平界面对目的层地震波振幅的影响  

Influence of overlying horizontal stratum on seismic amplitude of target zone

作　　者：邓帅[1] 刘学伟[1] 王祥春[1] DENG Shuai;LIU Xuewei;WANG Xiangchun(School of Geophysics and Information Technology,China University of Geosciences,Beijing 100083,China)

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

出　　处：《岩性油气藏》2017年第3期118-125,共8页Lithologic Reservoirs

基　　金：国家重点基础研究发展计划(973)项目"纵横波品质因子AVO反演方法研究"(编号:41604108)资助

摘　　要：地震波振幅属性是识别目的层岩性的重要参数,但该属性受上覆界面的影响较大。为了弄清上覆水平界面对目的层地震波振幅的影响,从正演模型出发,利用双程波动方程进行模拟,研究地震波在不同速度、不同尺度的上覆地层中传播时振幅的变化,建立上覆界面与目的层地震波振幅之间的联系,通过构建包含完美匹配层(PML)边界衰减系数的高阶交错网格有限差分公式,使用GPU进行并行计算加速,最终获得三维层状水平速度模型目的层地震波振幅的变化规律。结果表明,当上覆水平界面的反射系数发生变化时,目的层地震波成像振幅的变化范围及变化趋势都会随之发生相应的改变,尤其当上覆水平界面的反射系数趋于一致时,目的层地震波成像振幅便会发生异常性的变化。该研究成果可为地震资料处理解释过程中正确识别目的层岩性提供一定的理论帮助。Seismic amplitude is an important parameter to identify the lithology of target zone,however,it isgreatly affected by overlying stratum.Based on the forward modeling,the numerical simulation of two-way waveequation was applied to study the amplitude change of seismic wave when it travels through the overlying stratumwith different velocity and scale,and the relationship between the overlying stratum structure and seismicamplitude of the target zone was discussed.By building high ordered staggered-grid finite difference algorithmcontaining PML(perfect matching layer)attenuation coefficient and using GPU parallel acceleration,the amplitudechange regularity of the target zone of3D layered velocity model was defined.The experiment results showthat the amplitude of the target zone will change accordingly with the change of reflection coefficient of the overlyingstratum,and it will change abnormally especially when the reflection coefficient of overlying stratum tendsto be consistent.This study results are favorable for correct lithology identification by seismic data.

关 键 词：双程波动方程 正演模拟 反射系数 振幅属性 GPU 

分 类 号：P315.0[天文地球—地震学]