Abstract

Attenuation factor (1/Q) is an important indicator that is sensitive to hydrocarbon-bearing reservoirs. In attenuative media, seismic wave velocity is complex and frequency dependent, and 1/Q appears in the imaginary part of wave velocity. Focusing on the real part of complex wave velocity in attenuative media, we present new-parameterized P- and S-wave velocities, in which a maximum P-wave attenuation factor (\(1/Q_\mathrm{Pm}\)) is involved. Using solutions of Zoeppritz equations, we derive approximate PP- and PSV-wave reflection coefficients and anelastic impedances (AEI) as a function of \(1/Q_\mathrm{Pm}\), and we employ an empirical relationship to replace the S-wave attenuation factor with \(1/Q_\mathrm{Pm}\) in the derivation of PSV-wave reflection coefficient. Using the derived reflection coefficients and AEI, we establish an inversion approach and workflow of utilizing PP- and PSV-wave seismic amplitudes to estimate elastic parameters (i.e. P- and S-wave moduli, density) and anelastic parameter (i.e. \(1/Q_\mathrm{Pm}\)). Inputting different frequency components of PP- and PSV-wave seismic wave amplitudes, a model-based least-squares (LS) algorithm is employed to implement the deconvolution for estimating the PP- and PSV-wave AEI of different dominant frequencies and incidence angles, and the joint inversion of PP- and PSV-wave AEI for elastic parameters and attenuation factor is implemented using a Newton method. We employ synthetic seismic data of different signal-to-noise ratios (SNR) to verify the stability and robustness of the established inversion approach, and we finally apply the approach to real datasets acquired over a hydrocarbon reservoir. It illustrates that stable elastic parameters and attenuation factors may be estimated; and combining the inverted elastic parameters and attenuation factor, we may realize the reliable identification and interpretation of hydrocarbon reservoirs.

Article Highlights

• PP- and PSV-wave reflection coefficients and anelastic impedances are derived in terms of P- and S-wave moduli, density, and P-wave attenuation factor at the characterize frequency.

• Approach of joint inversion of PP- and PSV-wave seismic datasets for estimating P and S-wave moduli, density and P-wave attenuation factor based on first- and second-order derivatives of anelastic impedances is established.

• Tests on synthetic and real datasets imply the proposed inversion approach can be used as a valuable tool for generating reliable results of elastic properties and attenuation factor for hydrocarbon reservoir characterization.

中文翻译：

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使用弹性阻抗的二阶导数对衰减因子的 PP 和 PSV 波幅度的频率分量进行联合反演

摘要

衰减因子（1/ Q）是对含油气储层敏感的重要指标。在衰减介质中，地震波速度是复杂的和频率相关的，1/ Q出现在波速的虚部。着眼于衰减介质中复波速度的实部，我们提出了新参数化的 P 波和 S 波速度，其中最大 P 波衰减因子 ( \(1/Q_\mathrm{Pm}\) ) 为涉及。使用 Zoeppritz 方程的解，我们推导出近似的 PP 和 PSV 波反射系数和非弹性阻抗 (AEI) 作为\(1/Q_\mathrm{Pm}\)的函数，并且我们采用经验关系来代替 S - 波衰减因子与\(1/Q_\mathrm{Pm}\)PSV波反射系数的推导。使用导出的反射系数和 AEI，我们建立了利用 PP 和 PSV 波地震振幅来估计弹性参数（即 P 和 S 波模量、密度）和非弹性参数（即\(1/ Q_\mathrm{Pm}\)）。输入PP-和PSV-波地震波振幅的不同频率分量，采用基于模型的最小二乘（LS）算法实现反卷积，以估计不同主频率和入射角的PP-和PSV-波AEI，弹性参数和衰减因子的 PP 和 PSV 波 AEI 的联合反演使用牛顿方法实现。我们采用不同信噪比 (SNR) 的合成地震数据来验证已建立的反演方法的稳定性和鲁棒性，我们最终将该方法应用于在油气藏上获得的真实数据集。它说明了可以估计稳定的弹性参数和衰减因子；并结合反演弹性参数和衰减因子，

文章亮点

• PP 和 PSV 波反射系数和非弹性阻抗是根据 P 和 S 波模量、密度和 P 波衰减因子在特征频率下得出的。

• 建立了基于非弹性阻抗的一阶和二阶导数估计P波和S波模量、密度和P波衰减因子的PP和PSV波地震数据集的联合反演方法。

• 对合成数据集和真实数据集的测试表明，所提出的反演方法可用作一种有价值的工具，用于为油气储层表征生成弹性特性和衰减因子的可靠结果。