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Geoscience > Main Launcher > Horizon Menu > 2D Auto Picker

2D Auto Picker

The 2D Auto Picker application allows you to perform rapid auto picking on 2D lines using seed horizons on one or multiple lines. If a reference line is selected, it will start with this line and pick along this line. From there it will radiate outwards, picking the horizon for any lines that intersect this reference line that have been selected from the list of seismic lines. After picking these lines, it will pick the horizons for any lines that intersect those lines and so on.  If a reference line has not been selected, an arbitrary line will be used to start the process off.  The auto picker will attempt to correlate the lines across intersections using a mistie algorithm to. 

ClosedHow do I auto pick a horizon on 2D lines?

  1. Create a seed horizon by picking a horizon on any line. 

  2. Select the Seismic Lines to be auto picked from the list, or by selecting from the Basemap. Click on the Dataset cell to select a different version of the line.

  3. Select a Reference Line or lines.

  4. Select your Seed  Horizon from the drop down. The extension "AP2" is appended to the Output Horizon name, however you can rename the horizon.

  5. Set the auto picking parameters. By default your original picking mode parameters are set for the Search Gate/Mode and Event Type. You can run with the default settings and if you do not like the result, you can change and rerun the auto pick.

  6. Click  to perform the auto pick. You can view the results on the Basemap by selecting the horizon from the Horizon Toolbar.

If you leave the window open while you review the results, you can easily change the picking parameters and rerun the operation.

General Information


Seismic Lines

Select the lines you want to auto pick your 2D horizons on. The working set version is listed, but alternate datasets can be selected by clicking on the down arrow in the Dataset cell. Multiple lines can be selected using the Ctrl key on your keyboard, or by selecting an area on the Basemap.  To help you make your line selections, you can sort any column by left clicking on the column header, you can apply a filter (), or you can type a search string into the search bar.

For additional selection and navigation options right click on the Seismic Lines list to access the shortcut menu.

Reference Line (Optional)

You can select a reference line from a list of the active 2D seismic lines in the project.  If a reference line is used, the auto picker will start off using the horizon picked on this line.  You can specify a reference line if you believe that the horizon on this line is better quality than those on other lines.  If no reference line is selected, an arbitrary line will be used.  For additional selection and navigation options you can right click on the Reference Linelist to access the shortcut menu.

Auto Picking Parameters

The parameters fields will populate with default parameters based on the properties of the seed horizon, however you may want to change these parameters for optimal results.

Seed Horizon: This specifies the horizon to use as input for the auto pick process.  All picks in the seed horizon will be used as input to the process, and none of the original seed picks will be modified by the process.

Output Horizon: Specify the horizon to write out after the auto pick has been performed.  By default the horizon has the same name as the seed horizon with an " AP2" suffix added to it.  You may select another existing horizon from the list, enter a new horizon name or choose to overwrite the seed horizon with the resulting picks.

Search Gate: Specify the distance in milliseconds above and below an existing pick to try and perform the auto pick on the adjacent traces.  For example, a value of 20 will search 20 ms above the pick and 20 ms below the pick for the adjacent pick.

Search Mode: Specify how to decide between multiple events within the search gate.  This is only relevant for peak and trough picking modes.

Largest: Find the largest event within the search gate as the resulting pick.

Closest: Find the closest event within the search gate as the resulting pick.

Event Type: Set the type of event to look for.

Peak: A peak event is an event surrounded by lower amplitudes.  It need not be a positive value.

Trough: A trough event is an event surrounded by higher amplitudes.  It need not be a negative value.

Zero Crossing: A zero crossing event is an event that crosses from negative to positive or positive to negative values.  The zero crossing is picked sub-sample.

Peak/Trough Zero Crossing: This is an event that crosses from a positive to negative value.  The zero crossing is picked sub-sample.

Trough/Peak Zero Crossing: This is an event that crosses from a negative to positive value.  The zero crossing is picked sub-sample.

Correlation Window: The window in milliseconds in which to try to correlate the lines together.  A value of 500 means for the intersecting line try to find the best correlation 250 milliseconds above and 250 milliseconds below the pick.

Number of Traces: The number of traces that should be used in the correlation.

Confidence Cutoff: Specify the lower cutoff for rejecting potential picks when using the confidence value of the correlation.  If two lines do not correlate well, potentially other line intersections could be used to pick the horizon for the line if a minimum confidence is set.

Amplitude Cutoff: Specify the lower cutoff for rejecting potential picks when using amplitude correlation.  For example, a value of 80 means that any pick that has an amplitude value less than 80 % of the picks it is correlating against will be rejected.

Stop at faults: This directs the auto picker to stop trying to pick across a fault boundary.

Constraining Polygons: Open the Select Polygons dialog to select inclusion or exclusion polygons to define the limits of the auto pick.

Completing the 2D Auto Pick

OK: Complete the 2D auto pick and close the window.

Apply: Complete the 2D auto pick operation without closing the window. Selecting this option with allow you to change your parameters if you want to refine your results.

Also See

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