Reading multiple internal seismic files

Theory

Read multiple seismic module is used for reading multiple internal seismic files within g-Platform suite. It reads two types of files.

GSD - Geomage Standard Data

GSDL - Geomage Standard Data Light. This file contains only Trace headers information.

GSDL file is generated while using the following modules.

• Binning 3D
• Select traces
• Headers manipulation
• Create virtual geometry
• Kill empty traces
• Recreate sequence numbers
• Recalculate 3D offsets
• All regularization schemes.

GSDL file is used to optimize the memory usage where there is a huge input data or limited resources like physical RAM.

Input data

Input data/files need to be provided in the Parameters tab.

Parameters

Seismic file mask

provide the input files with special characters. Instead of reading all individual files one by one, use the mask file to call all the input files. For more information on these special characters, look into any regular expressions (Python RegEx)

[] - A set of characters

\ - Signals a special sequence

. - Any character (except newline character)

^ - Stars with

$ - Ends with

* - Zero or more occurrences

+ - One or more occurrences

? - Zero or one occurrences

{} - Exactly the specified number of occurrences

| - Either or

( ) - Capture and group

For example input files with a common name like "geom-map-red" can be read by using ".*geom-map-red.*".

Input files type { GSD, GSDL }

select the input file types from drop down menu. Click on the table/calculator icon and it will open a file path. Select the files from the database.

InputFilesType - GSD

it is Geomage internal format file type. Geomage Standard Data format.

Input GSD files

provide the individual input GSD files.

InputFilesType - GSDL

it is Geomage internal format file type however it contains only trace headers information.

Input GSDL files

select the individual GSDL files from the database path.

Read traces headers in RAM

by default, FALSE (Unchecked). This allows the user to read the input trace headers into RAM. Be cautious with this option in case the total number of input files are high.

Create files table

by default, FALSE (Unchecked). If TRUE, it will create the input GSD files in a tabular format.

Skip bad files

by default, FALSE (Unchecked). If TRUE, it will skip any bad files in the input file list and continue executing the workflow.

Auto-apply file mask on execution

this allows the user to extract the input files from the seismic file mask upon execution of the module.

Ignore additional headers

if the input files are having additional trace headers (created additional headers by user), it will ignore them. By default, FALSE (Unchecked).

Settings

Skip

By default, FALSE(Unchecked). This option helps to bypass the module from the workflow.

Output data

Output DataItem

Output SEG-Y data handle

generates output SEG-Y data handle.

Output traces data handle

generates output traces data handle can be used for connection/references

Files

generates the files list

Information

Files count

displays total number of input files

Traces count

displays total number of traces

Sample rate

displays the sample rate/interval of the input files.

Data length

displays the input files data/record length.

Domain

displays the input files domain (time/depth/frequency) type.

Examples

In this example workflow, we are reading multiple .gsd files using seismic file mask. We've provided the seismic file mask as ".*geom-map-red.*".

Click on "Apply seismic files from mask" action item

Click on the table/calculator icon against the Input GSD files parameter.

It will open a new window with all the input files.

How to create GSDL files?

GSDL files are internal file format files which stores ONLY trace headers information. As we mentioned earlier, it is advisable to use the GSDL file formats only when the user has limited resources w.r.t. physical memory i.e., RAM.

To generate these files, we read the input data by

Open seismic traces - this is used in case the input data size is too large/big.

Select traces - we are selecting CHANNEL < = 2 as an expression and save this trace headers information as a GSDL file.

To call GSDL file in Read multiple seismic module, select the input file type as GSDL and click on table/calculator icon. A new window opens with all available GSDL files in the database. Select the appropriate one by choosing from the list or create a seismic file mask as we described above and click "Apply seismic files from mask" action item to get the input GSDL files.

Actions

Apply seismic files from mask

this is applicable when the user uses "seismic file mask". After providing the input seismic files as seismic mask, click on this option and it will read all the input files.

Video lesson

YouTube video lesson, click here to open [VIDEO IN PROCESS...]

Related articles

Yilmaz. O., 1987, Seismic data processing: Society of Exploration Geophysicist

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