地震偏移成像分辨率的定量分析  

Quantitative analysis of resolution of seismic migration imaging

作　　者：狄帮让[1] 顾培成[2] 

机构地区：[1]中国矿业大学资源与安全工程学院,北京100083 [2]中国石油大学CNPC物探重点实验室,北京102249

出　　处：《石油大学学报（自然科学版）》2005年第5期23-27,32,共6页Journal of the University of Petroleum,China(Edition of Natural Science)

基　　金：'十五'中国石油集团重点科研项目(2000-1-1)

摘　　要：在理论分析的基础上,对地震偏移成像分辨率的定量分析过程进行了数值模拟实验。结果表明,影响偏移成像水平分辨率的主要参数是介质速度、地震子波主频和偏移处理的孔径角。在实验分析的基础上,给出了叠前、叠后偏移成像水平分辨率的经验公式。分析表明,加大孔径角是提高偏移成像分辨率的最有效途径,特别是当孔径角值从15°加大到45°时,分辨率迅速提高;在偏移噪音允许的前提下,偏移处理应尽量选用45°的大孔径角,至少应选择30°的孔径角。该经验公式虽然是在均匀介质条件下建立的,但同样适用于水平层状介质。在实际应用中,由于聚焦孔径角加大,观测系统范围也必须相应加大,否则经验公式失效。According to theoretical analysis, a large number of numerical simulation experiments were conducted to quantitative analysis of resolution of seismic migration imaging. The main parameters that effect horizontal resolution of migration imaging were identified as medium velocity, dominant frequency of seismic wavelet and aperture angle of migration processing. The empirical formula of horizontal resolution of pre-stack and post-stack were derived. The analysis results show that the best way to enhance resolution of migration imaging is to increase the aperture angle. The resolution was sharply increased when the aperture angle is set between 15° and 45°, Consequently, in consideration of migration noise, large aperture of 45°, or at least 30° was chosen. Although this empirical formula was derived under the assumption of homogenous medium, it can also be used in horizontal stratified medium. When the formulas are applied, the scale of the observation system due to the large focus aperture angle must be enlarged, or else the empirical formula will be invalid.

关 键 词：地震偏移 偏移成像 分辨率 偏移孔径角 数值模拟 经验公式 

分 类 号：P631.443[天文地球—地质矿产勘探]