基于入射角的AVO近似弹性波阻抗方程及反演  

Elastic Impedance Equation Based on the Incident-Angle AVO Approximation and Inversion

作　　者：李超[1] 印兴耀[1] 张广智[1] 张繁昌[1] 郑静静[2] 

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]中国石化胜利油田分公司物探研究院,山东东营257022

出　　处：《吉林大学学报（地球科学版）》2013年第5期1663-1671,共9页Journal of Jilin University：Earth Science Edition

基　　金：国家科技重大专项项目(2011ZX05009-003);国家"973"计划项目(2013CB228604);中国石油科技创新基金项目(2011D-5006-0301);中央高校基本科研业务费专项资金项目(11CX05006A;11CX06003A)

摘　　要：AVO技术在油气勘探中已经得到广泛应用,但是在应用Zoeppritz方程的线性近似方程时,通常是直接应用入射角代替平均角进行参数计算,这样做会给反演工作带来误差。基于入射角的AVO近似方程将反射系数表示为入射角的函数,可以解决常规计算中存在的误差。过程如下:首先,由基于入射角的AVO近似方程推导得到基于入射角的弹性阻抗方程,将其标准化以实现不同角度的弹性阻抗间量纲的统一,并通过经典的AVO模型验证其准确性;然后,建立基于新方程的弹性阻抗反演方法,对Marmousi2模型进行反演,与常规方法反演结果进行对比,结果表明,新方法得到的结果更加准确;最后,利用某实际工区数据进行反演,得到的结果与实际测井资料匹配效果很好,证明了该方法有很强的实用性。AVO techniques have been widely used in petroleum exploration. However, when the Aki-Richards approximation is used to calculate the PP wave reflection coefficients, the incident angle is usually used as the angle parameter instead of the average of the incident and refracted angle. This calculation will bring errors to the result of the prestack inversion. The Incident-Angle approximation is the function of the incident angle, which significantly reduces the errors. First of all, an equation named the Incident-Angle Elastic Impedance was proposed based on the Incident-Angle approximation to make the inversion of elastic impedance more accurate. The new elastic impedance was normalized to overcome the problem that its dimensionality varies with the incident angle. One classical AVO model was used to prove its accuracy. Secondly, a new inversion method was established based on the new equation. Comparison of inversion results of the Marmousi2 model with the conventional method showed that the new method was b matched well with etter. Finally, the new method was tested with a set of real the well-logging data, which proved its strong practicability. data. and the final resultmatched well with the well-logging data, which proved its strong practicability.

关 键 词：入射角的AVO近似方程 阻抗 入射角弹性阻抗方程 标准化 弹性阻抗反演 

分 类 号：P631.2[天文地球—地质矿产勘探]