Seismic feature class attributes
- Anders Moe
- Jon Mugaas
- Andreas Paulsen (Unlicensed)
- Stein Midtvaage
This section describes the fields in a seismic feature class.
| Field | Description |
|---|---|
| Name | Feature name - usually survey name or base name of SEG-Y file |
| SEGYFile | Absolute path of input seismic file on SEG-Y format |
| TextualFileHeader | The textual file header (EBCDIC header) in the SEG-Y file |
| URL | Absolute or relative path of the resulting file. Se URL examples below |
| Droid | If exported from Petrel: reference to cube within Petrel project. |
| SeismicZDomain | The Z domain of the seismic. Time or depth |
| SeismicZUnit | The unit of the Z domain of the seismic. 'ms', 'us', 'ns' or 'ps', for time domain, 'm', 'cm', |
| JobIdNo | From SEG-Y binary file header: Job identification number |
| LineNo | From SEG-Y binary file header: Line number |
| ReelNo | From SEG-Y binary file header: Reel number |
| NoOfDataTracesPerRec | From SEG-Y binary file header: Number of data traces per ensemble |
| NoOfAuxTracesPerRec | From SEG-Y binary file header: Number of auxiliary traces per ensemble |
| SampleInterval | From SEG-Y binary file header: Sample interval in microseconds |
| OrigSampleInterval | From SEG-Y binary file header: Sample interval in microseconds of original recording |
| NoOfSamplesPerTrace | From SEG-Y binary file header: Number of samples per data trace |
| OrigNoOfSamples | From SEG-Y binary file header: Number of samples per data trace for original recording |
| DataSampleFormatCode | From SEG-Y binary file header: Data sample format code |
| CdpFold | From SEG-Y binary file header: Ensemble fold |
| TraceSortingCode | From SEG-Y binary file header: Trace sorting code |
| SpMin | Minimum shot point number read from file. 2D only |
| SpMax | Maximum shot point number read from file. 2D only |
| SpStep | Step between shot points read from file. 2D only |
| InlMin | Minimum in-line number read from file. 3D only |
| InlMax | Maximum in-line number read from file. 3D only |
| InlStep | Step between in-lines read from file. 3D only |
| CrlMin | Minimum cross line number read from file. 3D only |
| CrlMax | Maximum cross line number read from file. 3D only |
| CrlStep | Step between cross lines read from file. 3D only |
| SampleMin | Minimum sample value of dataset |
| SampleMax | Maximum sample value of dataset |
| DelayRecTime | Delay recording time: the minimum Z value of dataset, in milliseconds |
| OriginX | X position of first inline and first crossline |
| OriginY | Y position of first inline and first crossline |
| EndFirstInlineX | X position of first inline and last crossline |
| EndFirstInlineY | Y position of first inline and last crossline |
| EndFirstCrosslineX | X position of first crossline and last inline |
| EndFirstCrosslineY | Y position of first inline and last crossline |
| SchemaVersion | The scema version of this featureclass |
| Dimension | Integer value. The value '2' for seismic lines, and '3' for seismic cubes. |
| FileSize_MB | The file size of the original Segy file in Megabytes |
| LastModified | Date and time of last modification to the file. |
| NoOfTraces | Number of traces in the Segy file |
| NoOfInvalidTraces | Number of invalid traces in the segy file. |
| SampleAvg | Average seismic sample value |
| SampleStdDev | Standard Deviation of the seismic samples |
| Histogram | Histogram of the seismic samples |
URL Examples:
For a ZGY file on a local disk at C:/example/seismicdata.zgy the URL will be:
file:///C:/example/seismicdata.zgy
For inline crossline and timeslice on disk stored as .tiff files named C:/example/seismicdata_crosslines.tif, C:/example/seismicdata_inlines.tif and C:/example/seismicdata_timeslices.tif the URL will be:
file:///c:/example/seismicdata.tif
For a seismic 2D line raster stored in the same file geodatabase as the featureclass with the name "seismicdata" the URL will be:
urn:name:seismicdata
Schema Versions:
Schema Version 3:
Prior to Schema 3 shot point attributes are stored as integer numbers. From Schema 3 shot point attributes are stored as decimal numbers.
Schema Version 4:
Prior to Schema 4 the sample interval was always stored in micro seconds. From Schema 4 the unit of the sample interval is read from the column 'SeismicZUnit'.