| OpendTect Workflows Documentation version 4.2 |
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Purpose: To flatten the seismic data while honoring hiatuses caused by non-deposition and erosion.
Theory: The Wheeler transform is the seismic equivalent of the geologic Wheeler diagram (= chrono-stratigraphic chart). In a Wheeler diagram, rock units are plotted in a 2D chart of geologic time (y-axis) versus space (x-axis). The diagram shows the temporal-spatial relationship between rock units. Gaps in the chart represent non-deposition or erosion. In a Wheeler transform, we flatten the seismic data (or derived attributes) along flattened chrono-stratigraphic horizons. The differences with the Wheeler diagram are: The vertical axis in the Wheeler transformed domain is relative geologic time (as opposed to absolute geologic time) and a Wheeler transform can be performed in 2D and 3D, whereas the Wheeler diagram is always 2D.
Software: OpendTect + Dip-Steering + SSIS
Work flow:
- Select a pre-calculated chrono-stratigraphy.
- Add a Wheeler scene and use the selected chrono-stratigraphy to flatten the seismic data (or attribute).
Tips:
- Instead of displaying the flattened seismic, display the chrono-stratigraphy itself in the Wheeler scene. This display is useful for studying the depositional history, especially if you also display the same line (+ chrono-stratigraphy) in the structural domain.