Singularity analysis: a tool for extracting lithologic and stratigraphic content from seismic data

To first order, seismic data provides the geologist and the geophysicist with information on the geometrical relationships between subsurface lithologic boundaries. Generally, this spatial information is used to construct conceptual geologic and process models with which to explain the origins of stratigraphic features. From such models we infer lithologic content. Various methods (e.g. AVO, Coherency Cubes, Difference Cubes) have been developed to extract or characterize lithologic information from seismic data. In this work, we apply a new method to seismic data, that of singularity analysis, in an attempt to extract lithologic information directly from the seismic trace. We propose that singularity order reflects the sharpness of the the lithologic boundary which generated a given seismic horizon – high-order (more negative) singularities correspond to abrupt facies transitions while low-order (less negative) correspond to more gradual transitions. Our results show that singularity order changes predictable along dip on stratigraphic surfaces and suggests that the method of singularity analysis reflects variations in the nature of the lithologic transitions responsible for the seismic reflections.