Introduction
The seismic interpretation tool lets you interpret horizons, faults and observations. This can be done both manually and automatically. In your Geocap project you will typically have an interpretation folder with one or more Ihorizon datasets, one Faults folder and one Observations folder.
The structure of a horizon in Geocap is as follows:
- One horizon can contain interpretation for several seismic lines
- Each line can have many segments
- Each segment can have many picks
This means that each horizon will normally contain thousands of picks along different seismic lines. Each pick is stored with the following information:
- Time value
- Seismic line name
- Shot point
The way Geocap stores its horizon data is compatible with most other seismic interpretation systems.
The seismic interpretation tutorial is found in the Shelf section [Seismic Interpretation].
Importing interpretation from external files
To import an existing interpretation from file, create an Interpretation folder and then right-click on the Interpretation folder and select Import > Interpreted Horizons. The external file must be on ASCII format with one pick per line. Each pick must contain position and shot point in addition to the name of the corresponding seismic 2D line.
An Import dialog appears. You'll most likely need to Adjust header and change File column for X, Y, Time, SP, and Data separator. Take a moment to inspect the Data separator. This should be the name of the corresponding seismic 2D line. The remainder of the panel settings are usually kept as is.
Read about how to import interpreted horizons in the import chapter Importing Interpretation.
Interpretation data structure
During interpretation (or import) a dedicated interpretation data structure is created. The base folder is an Interpretation folder. An Interpretation folder contains subfolders and IHorizons. An IHorizon (i.e. Interpreted Horizon) is the parent for any number of Pick Groups. Each Pick Group represents the interpretation of current horizon on a seismic line. The name of a Pick Group must and will be exactly the same as the corresponding seismic line.
Interpretation data structure
Interpretation interface
The seismic interpretation tool can be found under Tools > Seismic Interpretation.
The interpretation menu
Interpreting horizons
Use the Seismic Control tab when interpreting horizons. In the Data section you can browse in new interpretations and horizons or you can create new ones. The Edit button lets you change the properties and graphical settings of interpretations and horizons. You can display horizons in the graphical window directly from the interpretation menu without using the regular commands.
Before you can start interpreting you will have to select the seismic line you want to interpret on. Do this by displaying one or several seismic lines from the project and then use the Select button in the interpretation menu and click on the one you want to interpret.
Manual interpretation
Select the Snap mode you want to use. Geocap can snap to either max (peak) or min (trough) or none of them. Using the snap mode will help you increase the precision when interpreting. When you have set the tracking parameters click the Start interpretation button and start digitizing with P along the horizon. Click the Stop button to stop the digitizing.
Automatic interpretation
Geocap can track a whole seismic line automatically. This saves a lot of time when dealing with strong continuous reflectors. Select a snap mode and set the track mode to Auto. The delta Z value will constrain the auto-tracker to a time interval it is allowed to "jump" between each shot point. Click the Start interpretation button, point your mouse on the line you want to interpret, press P and Geocap will interpret the whole line.
You can also partially auto-track a line using the Insert tracking mode. Click the Start interpretation button, point your mouse where you want to start the interpretation, press P and the point the mouse where you want to end the automatic interpretation and press P. Geocap will then interpret this segment automatically.
Edit or erasing interpretation
You can edit the interpreted line by clicking the Start interpretation button and simply re-digitize the section you want to edit. Geocap will automatically update the line when you click the Stop button.
There are three options for erasing segments of an interpreted line:
- Between 2 picks - Use P to select which points to delete between
- Between beginning and pick - Use P to select end point.
- Between pick and end - Use P to select start point.
Use the Erase button to start erasing.
Interpreting faults
n/a
Interpreting observations
n/a