Shallow Geohazard Channel Identification Based On Novel Seismic Interpretation Techniques in South Caspian Sea

Abstract

Summary Shallow channels in the South Caspian Sea are major hazards which need to be identified on seismic data prior to well location positioning and drilling operation. We applied dip-steered-median filtering and automatic gain control to enhance the quality of seismic data during pre-processing. We calculated edge-sensitive attributes such as similarity, semblance and curvature on a migrated poststack channelized seismic volume from the South Caspian Sea. Afterwards, we de-striped the acquisition footprints along the inline direction which interfered with channel edge detection on seismic attributes based on factorial kriging. Moreover, we introduced shearlet edge detection algorithm as a novel edge-sensitive seismic attribute. Besides, we extracted a dense set of horizons (HorizonCube) after manually picking three horizons in the cube. We also investigated the existence of geohazards through geo-time slicing based on flattened seismic cube. Furthermore, we performed RGB blending of spectral decomposition components to visualize thickness variation within the channels. In the last step, the bodies of channels were successfully extracted using Thalweg tracker.