地震叠前共成像点道集属性增维分析与解耦合应用  

Dimension-increasing analysis and decoupling application of seismic pre-stack common imaging point gather property

作　　者：张明振 陈先红[1] 张猛[1] 江洁[1] ZHANG Ming-zhen;CHEN Xian-hong;ZHANG Meng;JIANG Jie(Geophysics Research Institute,Shengli Oilfield Company,Sinopec,Dongying 257022,China)

机构地区：[1]中石化胜利油田分公司物探研究院,东营257022

出　　处：《地球物理学进展》2020年第2期701-708,共8页Progress in Geophysics

摘　　要：地震叠前共成像点道集比成果资料蕴含更多的信息,分析其特征并有效应用,可提高地质目标的描述精度.本文创新将叠前共成像点道集分频构建三维数据体,多维度系统分析地震属性随偏移距、频率变化的耦合关系,明确了差异变化特征,找到了等效叠加成像后地震属性混叠的原因.理论与连续频率正演合成带限子波,进一步分析地震属性随频率变化特征,发现纯频子波与带限子波的属性差异,认为纯频子波比带限子波更能准确地反映地质目标.针对叠前共成像点道集属性差异,面向地质目标,提出了属性解耦合应用策略.在CD油田,选取叠前共成像点道集属性稳定部分叠加,消除偏移距对地震属性的影响,保真度提高,有效频带变宽,主频提高.分频处理消除不同频率间的干涉影响,面向目标优选出纯频体.纯频体与地质体对应关系稳定,反映微幅构造和储层特征更明显,可有效挖掘出地震资料的潜力,实现地质目标的精细描述.Seismic pre-stack common imaging point gathers contain more information than the result data. Their characteristics analysis and effective application can improve the description accuracy of geological targets. Prestack common imaging point gathers is configured innovatively into different frequency data volume which coupling relationship of properties with offset and frequency variation is analyzed systematically in multi-dimension. As a result the differences of properties’ characteristics are clarified, the causes of seismic properties aliasing after equivalent stacking imaging are found. Band-limited wavelet, synthesized through theory and continuous frequency forward, is used to analyze further seismic properties variation with frequency, and the differences of seismic properties obtained separately by pure-frequency wavelet and band-limited wavelet are found, which is considered that the seismic properties obtained by pure-frequency wavelet can more accurately reflect geological targets than that of band-limited wavelet. An application strategy of properties decoupling is proposed aiming at the difference of properties of pre-stack common imaging point gathers and facing geological targets. In CD Oilfield the stable part of pre-stack common imaging point gathers properties are selected to stack, eliminate the influence of offset on seismic properties, improve fidelity, widen effective frequency band and increase main frequency. Frequency division processing can eliminates the interference of different frequencies and optimizes the pure frequency volume for the target. The corresponding relationship between pure frequency volume and geological body is stable, reflecting the characteristics of micro-structure and reservoir more obvious, which can effectively tap the potential of seismic data and achieve the fine description of geological objectives.

关 键 词：叠前共成像点道集 属性差异 偏移距 频率 地震属性解耦合 纯频体 

分 类 号：P631[天文地球—地质矿产勘探]