Principles of seismic stratigraphy and seismic geomorphology I: Extracting geologic insights from seismic data

Abstract

With the advent of widely available 3D seismic data, numerous workflows focused on extracting subsurface stratigraphic information have been developed. We present here tools and rules that can maximize the amount of geologic information that can be extracted from seismic volumes. The fundamental principle enhancing the value of geologic insights extracted from seismic data is the integration of two disciplines: (1) seismic stratigraphy (i.e., images derived from section views that yield insights into stratigraphic architecture); and (2) seismic geomorphology (i.e., images derived from plan views that yield insights into paleo-landscapes). Both disciplines leverage the possibility of generating subsurface images in 3D with the objective of interpreting depositional environments and better predict lithofacies distribution both spatially and temporally. A second principle is that interpretation of geologically meaningful patterns derived from these two disciplines must be in agreement with each other. That is, interpretations based on observations from the geomorphological domain must be corroborated by interpretations based on observations from the stratigraphic domain, and vice versa. To achieve this, the workflows presented here illustrate multiple analytical approaches, which include: (1) initial reconnaissance through 3D volumes in several observational domains (e.g., section, plan and perspective views) with various slicing techniques and animation tools; (2) detailed focus on features of geologic interest that have been identified through reconnaissance, with further investigation through a combination of detailed slicing, horizon picking and seismic attributes calculation; and (3) comprehensive integration of seismic geomorphologic with seismic stratigraphic analyses to ensure consistent and reasonable interpretation of depositional environments and lithofacies. Context is highlighted as a critical underlying aspect of these workflows to help differentiate between reasonable and unreasonable interpretations, which constitutes a third principle of seismic stratigraphy and seismic geomorphology. It is not uncommon that a pattern observed in section or map view might be a non-unique indicator of a depositional environment; hence, knowing the context can be critical in making the correct geological interpretation of these non-unique patterns. From past to future, seismic stratigraphy and seismic geomorphology are two disciplines that, when integrated, play a fundamental role in resource exploration / production (e.g., hydrocarbon, water, hydrogen) and carbon storage, as well as providing enhanced understanding of the past evolution of Earth and prediction of its future (e.g., sea level and climate). Hence, awareness of the broad range of workflows available to extract geologic insights from seismic data is critical for both applied and fundamental sciences.