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在具有垂直对称轴横向各向同性介质中,利用四种参数来确定中间至远偏移距转换波(C-波)动校正。它们是C-波叠加速度VC2,垂直速度比和有效速度比γ和γeff,以及各向异性参数χeff。我们将这四种参数作为C波叠加速度模型。C-波速度分析的目的就是确定这种叠加速度模型。C-波叠加速度模型VC2,γ0,γeff,和χeff可以由P-波和C-波反射动校正资料获得。然而错误的传播是C-波反射动校正反演中的严重问题。当前短排列叠加速度由于是从双曲线动校正推算而得,因而其精度不足以为各向异性参数提供有意义的反演值。中间偏移非双曲线动校正不再被人们所勿略,而是可以用一个背景γ加以量化。非双曲线分析通过中间偏移距的γ校正量可以产生VC2,若数据不含燥音,其误差小于1%。方法稳健,允许γ启始假定值的误差达20%。该方法也适用垂直非均匀各向异性介质。精度的提高使能够用4分量地震资料计算各向异性参数。为此提出了两种工作流程:双扫描和单扫描流程。理论数据和实际数据的应用表明这两种流程得出的结果其精度相似,但是单扫描流程比双扫描更有效。
In a transversely isotropic medium with a vertical symmetry axis, four parameters are used to determine the mid-to-far offset converted-wave (C-wave) motion correction. They are the C-wave superposition velocity VC2, the vertical velocity ratio and the effective velocity ratios γ and γeff, as well as the anisotropy parameter χeff. We use these four parameters as the C-wave superposition model. The purpose of C-wave velocity analysis is to determine this superposition velocity model. The C-wave superposition models VC2, γ0, γeff, and χeff can be obtained from P-wave and C-wave reflection data. However, the wrong propagation is a serious problem in C-wave reflection correction. The current short-run stacking speed is inaccurately estimated to provide meaningful inversion of anisotropy parameters due to hyperbola kinematic correction. Intermediate Offset Non-hyperbolic kinematic correction is no longer omitted, but can be quantified using a background γ. Non-hyperbolic analysis VC2 can be generated by a gamma correction at mid-offset, with an error of less than 1% if the data does not contain a dry noise. The method is robust, allowing a tolerance of up to 20% of the assumed initial value of γ. This method also applies vertical heterogeneous anisotropic media. Increased accuracy enables the calculation of anisotropy parameters using 4-component seismic data. To this end, two workflows have been proposed: double scan and single scan. The application of theoretical data and actual data shows that the accuracy of these two processes is similar, but the single-scan process is more effective than double-scan.