对井间地震反射波的分析  

The analysis on reflection in crosswell seismic

作　　者：何惺华[1] 

机构地区：[1]中国石油化工股份有限公司胜利油田分公司物探研究院,山东东营257022

出　　处：《石油物探》2006年第5期520-526,共7页Geophysical Prospecting For Petroleum

摘　　要：井间地震反射波成像资料可以对井间地层和构造进行精细描述。对井间地震反射波的性质进行了讨论和分析。给出了反射波的基本性质,讨论了反射波系数与入射角的关系;分析了井间地震反射波的特点,反射波大都产生在检波器附近的深度范围,离震源和检波器越远反射能量越弱;讨论了大角度反射现象和大角度反射能量强的原因;利用实际资料对井间反射波的性质进行了分析,提出依据地层速度结构和井间地震观测方式来确定资料中的反射是大角度反射还是广角反射;利用模拟记录对广角反射现象进行了分析,得出波阻抗差为正值时,在临界角处产生广角反射且反射波极性发生翻转的结论;探讨了井间地震反射波振幅与频率等属性随入射角改变而变化的一般规律;提出对于广角反射造成的振幅、频率、相位畸变,可以采用有限角度叠加方法予以消除。实际资料处理证明采用此方法改善了叠加效果,提高了井间地震反射成像资料的信噪比和分辨率。Reflection imaging is able to characterize structure and stratum between wells in crosswell seismic. We analyze the characteristics on reflection and phenomena of reflection with big-angle in crosswell seismic data by basic theory of reflection. Undermentioned conclusions have been obtained from the analysis of actual data i reflection with big-angles is dominant in crosswell seismic, this is caused mainly by characteristics of radiant energy on direction of vibrater and geophone as well as the travel paths in crosswell seismic; velocity structure of stratum is a crucial factor to produce wide-angle reflectioa There are wide-angle reflections and more normal reflections with big-angle reflection produced from continental deposit basin in eastern China. The characteristic and various attributes of reflection are studied as incidence angle is changing in crosswell seismic models. The limited angles stack can be used to avoid the aberrance of amplitude and frequency caused by wide-angle reflection. This method enhances the S/N ratio and resolution of reflection image in crosswell seismic.

关 键 词：井间地震 反射波 广角反射 有限角度叠加 成像 

分 类 号：P631.4[天文地球—地质矿产勘探]