Interactive seismic flattening for geologically consistent interpretation.

Solene Panhaleux and M. Palomas and Emmanuel Malvesin and T. Laverne and Laurent Souche. ( 2013 )
in: Proc. 33rd Gocad Meeting, Nancy

Abstract

Building a geologically consistent interpretation of a structurally complex area (thrust belts, flowerstructures, etc.) is often a challenge, especially when the structure has to be interpreted from sparse data (e.g., 2D seismic lines) or when the quality of the seismic image is poor. Properly identifying reflectors (horizons, unconformities) across faults with large displacements, or in areas with little seismic signal correlation, can be particularly difficult. In a similar way correctly defining the location of fault surfaces and the contacts between them, while preserving consistent thicknesses and realistic fault displacement profiles, is often a delicate task. A solution to these problems is to perform detailed interpretation in a domain in which the considered seismic section has been unfaulted and unfolded in a mechanically consistent way, without breaking the immersive experience of seismic interpreters. In this paper we first present the algorithms and numerical techniques underlying the implementation of such a fully automated flattening approach. This near-interactive process, which has been integrated into a seismic interpretation platform, (1) is tolerant to minor flaws in the input interpretation, (2) accommodates very well sparse, noisy, or locally inaccurate interpretation data, (3) is able to handle the most complex structures (X, Y, λ, and thrust faults) and stratigraphic patterns (erosions, baselaps, etc) and (4) scales from reservoir to basin. The structural consistency is enforced by the use of physical laws that govern solid mechanics. Based on unstructured meshing and implicit function interpolation approaches, this process also automatically and quickly yields 2D watertight, faulted layer models of the interpreted sections. Two user workflows are then demonstrated on a complex seismic dataset from offshore Australia: (1) a control of the structural and stratigraphic consistency of an already interpreted seismic section, by verifying if it is properly balanced, and (2) an easy tracking of reflectors across faults, by interactively interpreting seismic horizons and truncation patterns into a mechanically-flattened section, from which most tectonic deformation has been removed (pseudo chronostratigraphic space). All horizons and layers can simultaneously be visualized in both initial (faulted and folded) and flattened domains while they are being interpreted. The process is repeated on several seismic sections, and the produced interpretations are used to build a large scale consistent 3D model.

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BibTeX Reference

@inproceedings{PanhaleuxGM2013,
 abstract = { Building a geologically consistent interpretation of a structurally complex area (thrust belts, flowerstructures, etc.) is often a challenge, especially when the structure has to be interpreted from sparse data (e.g., 2D seismic lines) or when the quality of the seismic image is poor. Properly identifying reflectors (horizons, unconformities) across faults with large displacements, or in areas with little seismic signal correlation, can be particularly difficult. In a similar way correctly defining the location of fault surfaces and the contacts between them, while preserving consistent thicknesses and realistic fault displacement profiles, is often a delicate task. A solution to these problems is to perform detailed interpretation in a domain in which the considered seismic section has been unfaulted and unfolded in a mechanically consistent way, without breaking the immersive experience of seismic interpreters. In this paper we first present the algorithms and numerical techniques underlying the implementation of such a fully automated flattening approach. This near-interactive process, which has been integrated into a seismic interpretation platform, (1) is tolerant to minor flaws in the input interpretation, (2) accommodates very well sparse, noisy, or locally inaccurate interpretation data, (3) is able to handle the most complex structures (X, Y, λ, and thrust faults) and stratigraphic patterns (erosions, baselaps, etc) and (4) scales from reservoir to basin. The structural consistency is enforced by the use of physical laws that govern solid mechanics. Based on unstructured meshing and implicit function interpolation approaches, this process also automatically and quickly yields 2D watertight, faulted layer models of the interpreted sections. Two user workflows are then demonstrated on a complex seismic dataset from offshore Australia: (1) a control of the structural and stratigraphic consistency of an already interpreted seismic section, by verifying if it is properly balanced, and (2) an easy tracking of reflectors across faults, by interactively interpreting seismic horizons and truncation patterns into a mechanically-flattened section, from which most tectonic deformation has been removed (pseudo chronostratigraphic space). All horizons and layers can simultaneously be visualized in both initial (faulted and folded) and flattened domains while they are being interpreted. The process is repeated on several seismic sections, and the produced interpretations are used to build a large scale consistent 3D model. },
 author = { Panhaleux, Solene AND Palomas, M. AND Malvesin, Emmanuel AND Laverne, T. AND Souche, Laurent },
 booktitle = { Proc. 33rd Gocad Meeting, Nancy },
 title = { Interactive seismic flattening for geologically consistent interpretation. },
 year = { 2013 }
}