Seismic Horizon Skeletonization

Abstract

Method for analysis of hydrocarbon potential of subterranean regions by generating surfaces or geobodies and analyzing them for hydrocarbon indications. Reflection-based surfaces may be automatically created in a topologically consistent manner where individual surfaces do not overlap themselves and sets of multiple surfaces are consistent with stratigraphic superposition principles. Initial surfaces are picked from the seismic data (41), then broken into smaller parts (“patches”) that are predominantly topologically consistent (42), whereupon neighboring patches are merged in a topologically consistent way (43) to form a set of surfaces that are extensive and consistent (“skeleton”). Surfaces or geobodies thus extracted may be automatically analyzed and rated (214) based on a selected measure (213) such as one or more direct hydrocarbon indications (“DHI”), e.g. AVO classification. Topological consistency for one or more surfaces may be defined as no self overlap plus local and global consistency among multiple surfaces (52).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional application 61 / 128,547 which was filed on May 22, 2008; U.S. Provisional application 61 / 131,484 which was filed on Jun. 9, 2008 and U.S. Provisional application 61 / 169,122 which was filed on Apr. 14, 2009.FIELD OF THE INVENTION[0002]This invention relates generally to the field of geophysical and geologic prospecting, and more particularly to the analysis of seismic data. Specifically, the invention is a method to create objects such as surfaces and geobodies, and to automatically analyze them with the purpose of highlighting regions with a potential to contain hydrocarbons. One particular embodiment of the invention is the simultaneous creation and analysis of many stratigraphically consistent surfaces from seismic data volumes.BACKGROUND OF THE INVENTION[0003]It is advantageous in seismic data processing and interpretation to reduce a seismic data volume to its internal reflection-...

AI Technical Summary

Benefits of technology

[0030]Further still, one or more embodiments of the method may include wherein merging neighboring patches in a topologically consistent way is performed by developing overlap and neighbor tables for the patches, generating an order for merge pair candidates by sorting the overlap and neighbor tables, checking candidate merges for topological consistency using the overlap and neighbor tables, and accepting topologically consistent mergers; wherein the sort order of the neighbor table is based on geometries of, or geometry differences between, the neighboring patches, or is based on the statistical properties of, or the differences between, one or more attributes extracted from seismic data collocated with the patches; wherein only unique correlations are accepted; identifying and also accepting multiply correlated connections characterized by two or more correlations from a single peak, trough or zero crossing all exceeding the threshold; spatially flattening the topologically consistent reflection-based surfaces into an order representing the sequence of deposition using the topologically consistent reflection-based surfaces and using the flattened surfaces to predict or analyze potential for hydrocarbon accumulations; flattening the associated seismic data within which the topologically consistent reflection-based surfaces exist; wherein the seismic data flattening is performed by nonlinear stretch of the seismic data or by a cut and past method; wherein every step is automated using a computer; repeating steps (b)-(c) at least once using the surfaces from step (c) of one iteration in step (b) of the next; creating a visual representation (i.e. a tree) showing depositional order or hierarchy of the topologically consistent reflection-based surfaces; using the tree to select one or more surfaces for visualization; using the patches to segment the seismic data volume into three-dimensional bodies or inter-surface packages that represent geologic units that were deposited within a common interval, and using them to analyze for hydrocarbon potential; analyzing the location and characteristics of edges and termination points of the topologically consistent reflection-based surfaces and using that to assist in predicting or analyzing potential for hydrocarbon accumulations; analyzing attributes and geometric characteristics of the topologically consistent reflection-based surfaces and / or the associated seismic data at the locations of said surfaces to assist in predicting or analyzing potential for hydrocarbon accumulations using the patches or topologically consistent reflection-based surfaces to reduce the amount of information contained in the seismic data volume in order, thereby reducing storage or computational efficiency requirements for subsequent data processing of the seismic data; and wherein merging neighboring patches is restricted to patches that trace back before shrinking to the same initial surface.

Problems solved by technology

Most of these methods create surfaces that eventually overlap themselves.

Ants follow each other's scent, and over time, short successful paths emerge.

However, the reference does not disclose the creation of surfaces, nor breaking or merging of surfaces, nor topology or topological consistency.

Images