OpendTect dGB Plugins User Documentation version 4.2
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4.4. Wheeler Transform / Wheeler Scene

4.4.1. Wheeler Scene

The Wheeler Scene in OpendTect is another scene, which is added from the SSIS menu. It may be noted that the Wheeler Scene is a transformation (flatenning) of HorizonCube into relative gelogical time (RGT). Therefore, before adding a Wheeler Scene, the HorizonCube should be selected.



In the Wheeler scene, flattened seismic data can be displayed by adding elements (inline, crossline, and timeslice) in the tree. By displaying flattened seismic data, one can assess the quality of the selected HorizonCube. Making a good HorizonCube is an iterative process. It will probably take several runs before the result is satisfactory. In order to improve HorizonCube the user can try to:
Note: In the Wheeler scene, stored data is transformed on-the-fly to the flattened domain. All attributes and neural network outputs are calculated in the normal domain first and then transformed to the Wheeler domain. Because of this transformation, quickly scanning through your Wheeler is only possible after creating a Wheeler cube. On-the-fly calculations are not supported for the volume viewer, which only accepts input from pre-calculated Wheeler cubes.

Below, the two types of Wheeler transformation are displayed. One with Continuous HorizonCube and the other is the same HorizonCube with a density filter. Note that for Wheeler Transformation, the closely spaced events in a continous HorizonCube needs to be filtered out so that the hiatus, and stratal terminations become prominent and one can interpret base-level changes.


Top scene is a display of a seismic data and the HorizonCube with continuous events. Bottom display is the Wheeler Transformed Scene of the HorizonCube. The same seismic data is displayed in the wheeler domain.


Top scene is a display of a seismic data and the continous HorizonCube with a density filter applied. Bottom display is the Wheeler Transformed Scene of the displayed HorizonCube. The same seismic data is displayed in the wheeler domain.

4.4.2. Create Wheeler Output (2D/3D)



A WheelerCube is a seismic volume in the Wheeler domain. When a WheelerCube is displayed on an element in the Wheeler scene, no transformation is needed as the Wheeler volume is created on-the-fly.

Note: Before creating a WheelerCube a HorizonCube must be selected.


Create Wheeler output volume for a 3D volume

Any stored 3D-data (seismic, attribute, neural network output) can be converted into the Wheeler domain. Select the stored volume you want to transform and specify a name for the WheelerCube. Moreover, the wheeler volume can be reduced by specifying the area-sub-selection. The Wheeler Cube is created in batch-mode (see corresponding section in the OpendTect User Documentation). A stored WheelerCube can be displayed by right-clicking an element in the tree, then click select attribute > Wheeler Cubes.


Create Wheeler output volume for a 2D Lineset/Line

For a 2D type of Wheeler transformation, 2D HorizonCube is required. Select the 2D HorizonCube in the input. This will be used as a transformation matrix for the Wheeler transformtion. Next, provide the input 2D data e.g. seismic/AI data. Optionally, you may create it for one line only and also restrict the output to a limited number of traces (Traces sub-selection). After this, the Wheeler output is stored to the written line-set and the attribute (format: Lineset_Name|Output_Wheeler_Attribute_Name).
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HorizonCube Slider   Flatten Horizon/Seismics