纵横波弹性阻抗联合反演方法

Joint Inversion of PP and PS Waves Elastic Impedance

在弹性阻抗反演方法的基础上,充分利用纵波和转换波地震信息,开展了纵横波弹性阻抗联合反演方法研究。首先对转换波反射系数近似精度进行对比分析,选取了转换波弹性阻抗近似公式,并对选取的转换波弹性阻抗公式进行标准化处理;其次详细研究了该反演算法的基本原理,并提出了具体实现流程;最后分别利用二维模型和实际工区的井数据制作叠前角度道集,添加随机噪声,对该反演方法进行模型试算。结果表明,纵横波弹性阻抗联合反演所得纵波速度、横波速度及密度估测值与真实值之间吻合较好;而且与单纯纵波弹性阻抗反演结果相比,纵横波弹性阻抗联合反演所得密度估测值更加稳定,从而为准确储层识别和流体检测提供了可靠的依据。

Based on elastic impedance（EI）inversion,we focused on the study of joint EIinversion of PP and PS waves using both PP and PS wave seismic data information.First,we analyzed the precision of different equations,choosing appropriate PS wave EIapproximate equation,and normalized the selected PS wave EIapproximate equation.Then,the study presented method of joint EIinversion of PP and PS waves,proposing the workflow of this method.Finally,for 2Dmodel and a well of a real project,it tested the method by adding random noise to angle gathers.The result showed that the estimated value of inverted P wave velocity,S wave velocity and density consisted with the real data.Meanwhile,in comparison with single P wave EIinversion,the estimated density of joint EIinversion of PP and PS waves is more robust.It can provide reliable basis for reservoir identification and fluiddetection.