Direct inversion for a fluid factor and its application in heterogeneous reservoirs
Direct inversion for a fluid factor and its application in heterogeneous reservoirs
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DOI：
10.1111/1365-2478.12038
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发表时间：
2013-09
影响因子：
2.6
通讯作者：
Z. Zong;Xingyao Yin;Guo-chen Wu
中科院分区：
文献类型：
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作者：
Z. Zong;Xingyao Yin;Guo-chen Wu
叠前地震反演在储层和地下流体敏感的弹性参数估计中起着重要作用。本文提出了一种基于部分角度叠加地震集的FMR‐AVA（流体因子、Mu（剪切模量）、Rho（密度）‐振幅随角度变化）同时反演方法。该方法可用于非均质储层流体系数、剪切模量和密度的直接反演。首先，基于P波和S波模量的孔隙弹性导出了反射系数的FMR近似方程。其次，提出了一种基于贝叶斯算法的稳定同步AVA反演方法。这种方法很少依赖于初始模型。此外，该方法还可应用于不容易建立初始反演模型的非均质储层。最后，模型试验表明了该方法在初始模型的稳定性和独立性方面的优越性。在光滑的初始模型和适度的高斯噪声条件下，得到了合理的流体因子、剪切模量和密度。实例数据表明，反演的流体系数、剪切模量和密度与测井解释结果吻合较好，验证了该方法的有效性。
Prestack seismic inversion plays an important role in estimating elastic parameters that are sensitive to reservoirs and fluid underground. In this paper, a simultaneous inversion method named FMR‐AVA (Fluid Factor, Mu (Shear modulus), Rho (Density)‐Amplitude Variation with Angle) is proposed based on partial angle stack seismic gathers. This method can be used for direct inversion for the fluid factor, shear modulus and density of heterogeneous reservoirs. Firstly, an FMR approximation equation of a reflection coefficient is derived based on poroelasticity with P‐ and S‐wave moduli. Secondly, a stable simultaneous AVA inversion approach is presented in a Bayesian scheme. This approach has little dependence on initial models. Furthermore, it can be applied in heterogeneous reservoirs whose initial models for inversion are not easy to establish. Finally, a model test shows the superiority of this FMR‐AVA inversion method in stability and independence of initial models. We obtain a reasonable fluid factor, shear modulus and density even with smooth initial models and moderate Gaussian noise. A real data case example shows that the inverted fluid factor, shear modulus and density fit nicely with well log interpretation results, which verifies the effectiveness of the proposed method.