基于FFD算子的衰减介质地震波模拟  

Seismic wave simulation in attenuation medium based on FFD operator

作　　者：何兵红[1] 吴国忱[1] 许冲[2] 

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266555 [2]中国石化江苏油田分公司物探技术研究院,江苏南京210046

出　　处：《石油地球物理勘探》2014年第1期153-160,305,共8页Oil Geophysical Prospecting

基　　金：国家科技重大专项(2011ZX05019-003);国家"973"项目(2013CB228604);山东省自然科学基金项目(ZR2010DM016)联合资助

摘　　要：本文推导了基于傅里叶有限差分(FFD)算子的衰减介质地震单程波波场传播算子,通过空间—时间域与波数—频率域之间的转化实现了衰减介质地震波场数值模拟。鉴于基于接收点波场向下延拓原理的非零炮检距正演模拟计算效率低,采用基于散射波Green函数积分解求取原理得到了叠前地震炮集记录。数值模拟结果表明,由衰减介质中FFD算子所得波场比分步傅里叶(SSF)算子所得波场具有更准确和更丰富的地层信息,特别是在地层存在陡倾角时效果更明显。针对实际资料含气储层地震同相轴下拉现象,通过井、震结合建立符合实际地质构造层位特征的理论模型,通过对正演结果的处理验证了地层强吸收导致地震反射同相轴下拉现象的解释,也为低频阴影现象的产生机制提供了一定的依据。We propose the FFD operator for seismic oneway wave propagation in attenuation medium to achieve seismic wavefield numeral simulation in attenuation medium by transformation between space-time domain and the wavenumber-frequency domain.Since the numeral simulation of offset data in wavefield downward is not efficient,we apply Green's function integral solution of scattered wave to improve the computation efficiency.Results of numerical simulation of seismic wave propagation in attenuation medium indicate that the FFD operator is more accurate than the SSF operator,especially for steep dip layers.As we know,when seismic wave travels through gas reservoir,reflection delays occur.In this paper,we prove the contribution of stratigraphic absorption to the delay through the simulation based on the models built by seismic and well data.At the same time,we provide the mechanism of low-frequency shadow phenomenon.

关 键 词：FFD算子 地层吸收 同相轴下拉 低频阴影 

分 类 号：P631[天文地球—地质矿产勘探]