The flattening and un-flattening workflow can be used for SSIS interpretations specifically in structurally distorted regions. The workflow starts with flattening a volume/line using a reference horizon. The selected seismic data and horizons are flattened into a new survey. In this flattened survey, the SteeringCube can be prepared, followed by processing of the HorizonCube. After the HorizonCube in the flattened survey is satisfactory, it can be un-flattened in the parent (un-flattened) survey for further SSIS interpretation.
To flatten a 3D survey using a reference horizon, this window is used. It can be launched from the SSIS menu. The input Reference Horizon is selected from the active survey, which would be used as a datum for the flattened survey. This datum is a Reference Z(ms) value. The corresponding seismic volume is selected in the Input Cube field. This volume would be used to prepare SteeringCube (for HorizonCube) in a flattened survey. Optionally, volume sub-selection can also be made to do work in a sub-volume.
The Target Horizon(s) are selected as these horizons are used as input in the HorizonCube, for building the framework. In the list one or more horizons can be transformed in the selected output i.e. a flattened survey (give a name in the Select Survey field).
Mode: Flattening / un-flattening mode. If flattening is set here, the selected data from the active survey will be flattened in a new (flattened) survey. The un-flattening mode is used to un-flattened a flattened (active) survey.
After providing the right selection(s), the user may proceed further by clicking on the Proceed button. This will start a batch program. Optionally, the user may run the batch program on a remote host by checking the Show Option(s) box before pressing the Proceed button.
Flattening a 3D seismic data and the horizons to prepare a HorizonCube in a flattened survey.
2D Survey
The same workflow can be applied for a 2D survey. If the window is launched in an active 2D survey, the 2D lines and the corresponding 2D horizons can be flattened using a reference horizon. The reference horizon defines a flattening datum with a given Reference Z value. This is selected from the Input Reference Horizon field. The 2D lines available in a Lineset are selected for the Lineset/Line Name option by pressing the select button.
Together with the seismic data, the corresponding 2D horizons from the active survey may also require flattening. These horizons are selected from the Target Horizon(s) field. Finally, select the flattening mode, and give an appropriate output survey name and press the Proceed button.
Flattening 2D seismic lines and the horizons for preparing a HorizonCube in a flattened survey.
The HorizonCube calculated in a flattened survey can be transformed back to its parent (un-flattened) survey. A input reference-horizon for the 2D/3D case needs to be provided. The horizon should be the same as the one selected to create a flattened survey. The input flattened 2D/3D survey, in which the HorizonCube is prepared, is selected from the Select Survey field. The input flattened HorizonCube available in the selected survey is selected in the Input HorizonCube field. Finally the output name for the HorizonCube is given. If the 'OK' button is pressed, the batch program will start to transform the flattened HorizonCube (2D/3D) into a un-flattened HorizonCube in the active survey.
Un-flatten a HorizonCube from a 3D flattened survey.
Un-flatten a HorizonCube from a 2D flattened survey.
