论文标题
剩余prestack迁移的运动学方面
Kinematic aspects of residual prestack migration
论文作者
论文摘要
在这项贡献中，可以证明，可以使用残留迁移概念的各个方面，以便为地震调查进行了prestack时间或深度迁移，并提供了新的深度：通过确定来自Aplanatic Curves的单个痕迹事件的旅行时间来引入残留迁移的概念。这些事件以适合新速度模型的合适配置进行迁移，为此，可以为此提供Kirchhoff Prestack Depth迁移的射线跟踪集。可以以各种方式利用所得的转换来估计重要参数，例如相对于相应的零偏移位置的迁移事件的位置偏置以及新深度模型的剩余移动；最后，提出了一种新的方法来估计第一个prestack迁移的费索区域的孔径宽度。可以估计各种映射的Prestack迁移，包括带有消除位置偏见的Prestack时间迁移。可以从一阶菲涅尔区域的孔径宽度和特定偏移时的位置偏置中评估新的prestack深度迁移的必要性。可以获取其他运动参数以进行残留的prestack迁移，尤其是必须执行残留求和的曲线。该方法适用于各向同性和各向异性PSTM和PSDM。与完整的PSDM相比，实施的计算成本较低。 在附录中，为小型到中间源接收器偏移的Prestack时间迁移的迁移速度得出了一个公式。速度可以从不均匀的各向异性深度模型或先前迁移的残余移动分析中确定。
In this contribution it is shown that various aspects of the concept of residual migration can be utilized for the case that a prestack time or depth migration has been performed for a seismic survey and a new depth is available: The concept of residual migration is introduced by determining travel times of reflected events for individual traces from aplanatic curves. These events are migrated in suitable configurations for the new velocity model for which a raytracing set as required for a Kirchhoff prestack depth migration is available. The resulting transformations can be utilized in various ways to estimate important parameters such as the positional bias of migrated events with respect to the corresponding zero offset position and the residual moveout for the new depth model ; finally a new approach is suggested to estimate the aperture width over the Fresnel zone for the first prestack migration. Various mapped prestack migrations can be estimated, including a prestack time migration with eliminated positional bias. The necessity of a new prestack depth migration can be assessed from the aperture width over the first order Fresnel zone and from the positional bias at a particular offset. Additional kinematic parameters can be acquired for a residual prestack migration, in particular the curves over which the residual summation has to be performed. The approach is applicable to isotropic and anisotropic PSTM and PSDM. Computational costs of the implementation are low when compared to a full PSDM. In the appendix a formula is derived for the migration velocities for a prestack time migration for small to intermediate source receiver offsets. The velocities can be determined either from an inhomogeneous anisotropic depth model or from residual moveout analyses of a previous migration.
