Introduction
You can use the SEG-Y Analysis Analyzer dialog to analyse analyze SEG-Y files. Using the dialog you can scan the file and then save the file layout configuration parameters as a JSON file. Later when reading the SEG-Y file using one of the SEG-Y reader tools tools you can provide this parameter configuration file to ensure correct reading.
...
The above figure shows the dialog for 3D files. The 2D version is is similar. The main difference is that you will have to set the shot point byte position positions for both inline and crossline in the 3D import, while in 2D there is of course only one shot point column. The 2D import also has a Analyze panel that lets you fix anomalies in the SEG-Y file.
For more information about the SEG-Y format, see the SEG page SEG-Y standard: http://www.seg.org/resources/publications/misc/technical-standards
Analyzing a SEG-Y file
To analyze a SEG-Y file:
...
EBCDIC Header
The SEG-Y EBCDIC header (textual file header) contains 3200 bytes of readable characters. SEG-Y revision 1 allows the header to be encoded in ASCII. Use the encoding combobox to switch between EBCDIC and ASCII encoding. The resulting data set's name in the Project Manager is either based on the file name or byte positions in the EBCDIC header. To set EBCDIC header byte positions simply highlight the section you want as data set name. The label between the comboboxes always shows current name.
...
- Shot point or Inline, Crossline: Type, Byte pos., Min, Max, and Step can be adjusted
- Scaler (X,Y): Value and Byte pos. can be adjusted; Type is fixed to Integer16 and Byte pos. is fixed to the two bytes immediately preceding X
- X: Type and Byte pos. can be adjusted
- Y: Type is fixed to the same as X and Byte pos. is fixed to the corresponding bytes immediately succeeding X
- Z: Type, Byte pos., Min, Max, and Interval can be adjusted
...
| Tip |
|---|
Before importing multiple SEG-Y files, try importing a single files file making sure that your settings are correct. Make a note of your settings. |
...
Make sure you have read about the different elements of the import menu above, before you read this section.
Import of 2D 3D seismic can be done in 3 steps:
...
If the Min and Max values for Inline or Crossline looks odd, the byte position could be wrong. The default byte positions in the SEG-Y 3D import is 59-812 for Inline and * 21-24 for Crossline in the trace header, but in some cases this is not always correct. If the byte position is wrong try the following:
...