A common task in seismic reflection imaging is to generate a structural image of the subsurface. However, the transformation from the pre-stack time domain to the depth domain requires an a priori unavailable model of propagation velocities in the subsurface. The Common-Reflection-Surface (CRS) stack is an entirely data-oriented approach that avoids the explicit parameterization of the depth model: it makes direct use of the inherent redundancy in the pre-stack data and parameterizes the reflection events in the time domain. By means of coherence analysis in the pre-stack data, an approximation of the kinematic reflection response of the CRS can be determined that fits best the actual reflection event. In addition to a high quality zero-offset simulation, the parameters of the CRS stacking operator, the so-called CRS wavefield attributes, are available at any location and allow a variety of useful applications. In this thesis, I derive the CRS stacking operator for 2-D data acquisition based on the concepts of geometrical optics using object and image points. I introduce a new, extended strategy to determine the CRS parameters that also allows to handle intersecting events. Concepts of Kirchhoff migration and CRS stack are merged to obtain new applications of the attributes. I present an implementation of the extended CRS stack strategy including applications of the wavefield attributes. Conventional imaging methods and the CRS stack are compared for three marine data sets, accompanied by applications of the wavefield attributes. I discuss specific features of the data examples, e. g., multiples, dominant diffraction patterns, and strong variations of the wavefield complexity.
|Versandkostenfrei innerhalb Deutschlands|
Wollen auch Sie Ihre Dissertation veröffentlichen?