The time-depth conversion process is a significant task in seismic interpretation to establish the link between geophysical information in the time domain and geological information in the depth domain at/away from well locations. Selecting the suitable velocity model for time-depth conversion to generate an accurate depth map is difficult if the accuracy of these models is unknown. In the current study, the cross-validation technique is used as a tool to diagnose and evaluate the performance of time-depth conversion at/away from well controls to predict the depth of Top Hartha and Zubair reservoirs using the dataset of East Baghdad Oil Field. To test this technique, four common velocity model approaches used for time-depth conversion with different scenarios of velocity parameters (initial velocity V₀ and depth gradient (K)) were applied to produce ten velocity models (1–10). According to the gradient variation of velocity with depth, check shot analysis, the velocity models (1–10) include three key velocities layer-cakes: Layer 1 (Middle Miocene-Upper Cretaceous), Layer 2 (Upper Cretaceous), and Layer 3 (Lower Cretaceous) with 18 horizons from Middle Miocene down to Lower Cretaceous. The cross-validation analysis reveals that the velocity model with a variable surface initial velocity and constant depth gradient (Model 9) was the most accurate with fewer mistie between actual and predicted depth. Consequently, this model is used to construct the depth map of the Hartha and Zubair reservoirs. Finally, this study progresses a workflow that can be applied to the region with any geological setting to investigate time-depth conversion uncertainty.

时深转换过程是地震解释中的一项重要任务，用于建立时域地球物理信息与井位/远离井位的深度域地质信息之间的联系。如果这些模型的准确性未知，则很难选择合适的速度模型进行时深转换以生成准确的深度图。在目前的研究中，交叉验证技术被用作一种工具来诊断和评估井控/远离井控的时间深度转换性能，以使用东巴格达油田的数据集预测 Top Hartha 和 Zubair 油藏的深度. 为了测试这种技术，四种常见的速度模型方法用于时间深度转换，具有不同的速度参数场景（初始速度V ₀和深度梯度 ( K)) 被应用于产生十个速度模型 (1-10)。根据速度随深度的梯度变化，校验炮分析，速度模型（1-10）包括三个关键速度层饼：第1层（中中新世-上白垩世），第2层（上白垩世）和第3层（下白垩世）从中新世到下白垩世有 18 个层位。交叉验证分析表明，具有可变表面初始速度和恒定深度梯度的速度模型（模型 9）是最准确的，实际深度和预测深度之间的差异较小。因此，该模型用于构建 Hartha 和 Zubair 水库的深度图。最后，这项研究提出了一个工作流程，可以应用于具有任何地质背景的区域，以调查时间深度转换的不确定性。