AVO正演方法及其应用

Fozward AVO methol and its application

建立在水平叠加基础上的传统的“亮点”技术的缺点之一是;叠加破坏了真实的振幅关系,同时也损失了CDP道集中有用的AVO信息,从而降低了地震信息识别岩性及油气藏的能力。现代的“亮点”技术应该建立在AVO分析的基础上,用真正的零偏移距剖面取代叠加剖面。随着AVO技术的广泛应用,人们已经注意到AVO技术也存在一些缺陷。本文就此分析了“亮点”技术和AVO技术存在的陷阱,并利用模型正演方法分析了不同地质条件下油气层的AVO显示特征。同时指出AVO分析不应该仅仅注意AVO增加现象,应结合本地区油气藏分布规律,建立相应的AVO检测标志。文中还提醒人们注意广角AVO现象在岩性识别和检测中的潜力。

One deficiency of traditional 'bright spot'technique based on hor- izontal stacking is that stacking destroys real amplitude relation and loses useful AVO informations in CDP gather, decreasing people's abi- lity to indicate lithology and hydrocarbon accumulation by using seis- mic informations. Modern 'bright spot' technique should be based on AVO analysis and uses zero-offset section instead of stack section. With the wide use of AVO technique, people have noticed its some deficiencies. Thus, some traps of 'bright spot' and AVO techniques are pointed out here. AVO preperties of hydrocarbon reservoirs under dif- ferent geological conditions are analysed by using forward modeling. It is pointed out that in AVO analysis, we not only pay attention to AVO enhancement but also define a relevant AVO detection criterion according to local reservoir distribution. The paper also suggests peo- ple to notice the potential role of wide-angle AVO phenomenon in lithology analysis.