Applying the CRS Stack Method to Solve the Problem of Imaging of Complex Structures in the Zagros Overthrust, South West

Abstract

Imaging in complex structures poses difficulties that could not be solved by conventional processing. In such cases, applying a full prestack depth migration (PSDM) is an alternative. However, this may not be applicable in all situations due to difficult migration velocity model building. The other alternative for imaging in complex structures is to perform poststack migration on a suitable stack section. Using a time section obtained by the Common Reflection Surface stack method could partially solve some of the imaging problems without requiring a prestack depth migration. A seismic data set of a mountainous area from the complex structure of the Zagros overthrust in south west of Iran was processed by the conventional NMO/DMO/Stack. The CMP-stacked section contained a folding system and dipping layers, but both of them not well imaged in the section. Then, the common reflection surface stack method was applied to data. In the CRS-stacked section, the folding and dipping layers were clearly observed. The other reflection and diffraction events at large travel times were also imaged. Therefore, the CRS-stacked section showed that the common reflection surface stack could be used to partially solve some of the problems with complex structures.