球面波反射和透射系数频变机制研究及考虑频变的地层Q值估计

项目名称： 球面波反射和透射系数频变机制研究及考虑频变的地层Q值估计

项目编号： No.41304108

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 袁三一

作者单位： 中国石油大学（北京）

项目金额： 25万元

中文摘要： 地震波速度随频率变化而引起的衰减与频散机制已被广泛研究，并在地震勘探中得到了有效的应用。但是目前已有的衰减解释理论没有关注球面反射和透射系数随频率变化而引起的地震波衰减问题。这种由波前曲率引起的地震波频变机制不同于地层固有衰减引起的频变机制。当球面反射和透射系数频变相对于地层固有衰减引起的频变不能忽略时，球面反射和透射系数频变则会影响地层品质因子（Q值）估计的精度，进而会影响后续的反Q滤波、偏移和解释的质量。本课题针对勘探地震波频带范围，研究球面反射和透射系数频变机制，这对丰富和发展地震波传播理论，具有重要的理论价值。在忽略其它影响地震波衰减因素的前提下，结合数值模拟和物理模拟实验，量化球面反射和透射系数频变的强度，量化球面波前曲率引起的地震波衰减与地层吸收引起的地震波衰减之间的差异，在前人研究基础上提出一种考虑球面反射和透射系数频变的Q值估计新方法，提升Q值估算精度，具有重要的实际意义。

中文关键词： 球面波；频变机制；地震波衰减；品质因子；

英文摘要： The seismic attenuation and dispersion mechanism caused by the frequency-dependent seismic velocity has been widely studied, and effectively applied to seismic exploration. However, the present attenuation theories do not involve or pay attention to the seismic attenuation caused by the frequency-dependent spherical reflection and transmission coefficients. The frequency-dependent mechanism caused by the spherical wavefront curvature is quite different from that caused by the inherent attenuation of the layer. When the frequency-dependent intensity caused by the spherical reflection and transmission coefficients is non-ignorable compared with that due to inherent attenuation of the layer, the accuracy of Q estimation is lowered, and the following inverse Q filtering, seismic migration and interpretation are influenced. In this project, the frequency-dependent mechanism of spherical reflection and transmission coefficients will be studied within the seismic frequency band, which has important theoretical significance for the development of seismic wave propagation theory. Taking no account of the other factors that lead to the seismic attenuation, the project will quantize the frequency-dependent intensity of spherical reflection and transmission coefficients, and quantize the difference between the attenuation c

英文关键词： Spherical wave；Frequency-dependent mechanism；Seismic wave attenuation；Quality factor；