基于薄层的反射系数谱理论与模型正演

一般的反射系数计算都是以单个界面为基础来进行的 ,而陆相地层主要以薄 (互 )层为主 ,这是一个矛盾。该文在推导出任意入射角入射条件下的多个薄层纵、横波反射系数谱理论基础上 ,进一步简化出了单个薄层垂直入射时的纵波反射系数谱计算公式 ,从而获得了在薄层条件下不同频率成分的纵波反射系数谱数学关系式。由此进一步形成了面向背景的纵波反射模型正演方法。通过采用实际地震子波为输入子波 ,对单个楔状体薄层、薄互层组楔状体地质模型进行了纵波合成记录制作。分析表明 ,其实用性强。不仅提供了一种基于新方法的合成模拟手段 ,更为横向谱比的物理意义分析提供了手段。

REFLECTANCE SPECTRUM THEORY AND MODEL COMPUTATION BASED ON THI N BEDS

The reflectance spectrum theory and model computation are based on thin beds.Generally, the compution of reflectance is based on a single reflector. However, the strata of the continental sedimentary basins are mainly based on thin bedes. After deriving the equations of reflectance spectrum of compressional and shear waves for thin beds at an arbitrary incidence angle, the equations of reflectance spectrum of compressional wave for a thin bed are reduced at zero incidence angle. Then, the model computation for the compressional wave is established at time varying wavelet. The principle for seismic model of thin beds is obtained and provides a means for physical and geological meanings of spectrum ratios along event.