Evaluating structural uncertainties associated with seismic imaging and target horizons can be of critical importance for decision making related to oil and gas exploration and production. An important breakthrough for industrial applications has been made with the development of industrial approaches to velocity model building. We have developed an extension of these approaches, sampling an equiprobable contour of the tomography posterior probability density function (PDF) rather than the full PDF, and using nonlinear slope tomography. Our approach allows for assessing the quality of uncertainty-related assumptions (linearity and Gaussian hypothesis within the Bayesian theory) and estimating volumetric migration positioning uncertainties (a generalization of horizon uncertainties), in addition to the advantages in terms of computational efficiency. We derive the theoretical concepts underlying this approach and unify our derivations with those of previous publications. Because the method works in the full model space rather than in a preconditioned one, we split the analysis into resolved and unresolved tomography spaces. We argue that resolved space uncertainties are to be used in further steps leading to decision making and can be related to the output of methods that work in a preconditioned model space. Unresolved space uncertainties represent a qualitative by-product specific to our method, strongly highlighting the most uncertain gross areas, thus useful for quality control. These concepts are developed on a synthetic data set. In addition, the industrial viability of the method is determined on two different 3D field data sets. The first one consists of a merge of different seismic surveys in the North Sea and indicates the corresponding structural uncertainties. The second one consists of a marine data set and indicates the impact of structural uncertainties on gross-rock volume computation.

中文翻译：

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与结构成像相关的断层扫描速度不确定性

评估与地震成像和目标层位相关的结构不确定性对于与石油和天然气勘探和生产相关的决策至关重要。随着建立速度模型的工业方法的发展，工业应用取得了重要突破。我们已经开发了这些方法的扩展，对断层扫描后验概率密度函数 (PDF) 而不是完整的 PDF 的等概率轮廓进行采样，并使用非线性斜率断层扫描。我们的方法允许评估与不确定性相关的假设（贝叶斯理论中的线性和高斯假设）的质量并估计体积迁移定位的不确定性（地平线不确定性的概括），除了在计算效率方面的优势。我们推导出这种方法背后的理论概念，并将我们的推导与先前出版物的推导统一起来。由于该方法适用于完整模型空间而不是预处理模型空间，因此我们将分析分为已解析和未解析断层扫描空间。我们认为已解决的空间不确定性将用于导致决策的进一步步骤，并且可能与在预处理模型空间中工作的方法的输出相关。未解决的空间不确定性代表了我们方法特有的定性副产品，强烈突出了最不确定的总区域，因此对质量控制很有用。这些概念是在合成数据集上开发的。此外，该方法的工业可行性取决于两个不同的 3D 现场数据集。第一个由北海不同地震调查的合并组成，并表明相应的结构不确定性。第二个由海洋数据集组成，表明结构不确定性对总岩石体积计算的影响。