影响薄互层地震反射波特征因素分析

FACTORS ANALYSIS AFFECTING SEISMIC REFLECTION CHARACTERISTICS OF THIN INTERBEDDING

通过对楔状模型，两层、多层介质等厚或不等厚模型和实际井中反射系数序列的频谱分析，和对用不同主频、不同类型、不同衰减系数子波的合成记录剖面的波形分析以及合成记录的频谱分析，初步认为：薄互层的单层时间厚度、子结构厚度是决定反射波特征、频谱特征的基础，薄互层的互层数、入射子波是重要的影响因素；在目前的常规地震勘探中，薄互层地震反射波多以时间不可分辨的面貌出现，因此为了得到特定薄互层结构的可分辨的最佳图像，必须选择与其相适应的入射子波；采用宽高频、高衰减系数的入射子波仍是目前提高地震勘探分辨率的主要途径之一，而提高采样率则是今后提高地震勘探分辨率的主要出路之一。

Analyses,on amplitude spectra from wedge model,two layers,or multi layers with equal thickness or unequal thickness models,and logging reflection coefficients sequence and on synthetic seismic reflection using different main frequencies,different types,different attenuation coefficient wavelet as well as on amplitude spectra of synthetic seismic reflection,have come to conclusions:single layer thickness,subroutine structure thickness of thin interbedding are the essential generating reflection features and amplitude spectra features and layer number of interbedding,incident wavelet cause great influence on them;in present convention seismic exploration,the reflection features from the thin interbedding usually occur as complex waves which can not be distinguished visually,in order to get a good reflection configuration of thin interbedding which can be used to interpretation,we must select a wavelet which consists with it;wide band high frequency and high attenuation coefficients incident wavelet are commonly used to improve the resolution of seismic exploration at present,and sample rate raised will be one of main outlets for improving the resolution of seismic exploration in the future.