SEGZ examples

THe following table contains numerous different data sets that demonstrate the differences I have seen in segy files from various sources. The Perl script, segz2segy.pl is provided to parse the segy files with the instructions in the .fmt file, prepare a simple report for those data fields and generate a BIG endian CSEGY 1994 segy data set(SOURCE_POINT times 1000).

Please notice that these files mostly follow the EnCana naming standard: LineID.LineName.Process.YearMonth.processor
Description SEGY Name Format File Output CSEGY Name
Paradigm's SEISX format, SOURCE_POINT is IEEE4 A3855.84945-84.2D.f-mig-prena.200707.cnc.0.segy A3855.84945-84.2D.f-mig-prena.200707.cnc.0.fmt A3855.84945-84.2D.f-mig-prena.200707.cnc.0.txt A3855.84945-84.2D.f-mig-prena.200707.cnc.0.csgy
ARAM Aires Little Endian Disk format, ASCII in trace headers 00000007.sgy 00000007.fmt 00000007.txt 00000007.csgy
PanCanadian segy standard, SOURCE_POINT is IBM float P1689.AM-CGG-16.f-mig-fx-zd.051994.gox.segy P1689.AM-CGG-16.f-mig-fx-zd.051994.gox.fmt P1689.AM-CGG-16.f-mig-fx-zd.051994.gox.txt P1689.AM-CGG-16.f-mig-fx-zd.051994.gox.csgy

Please note that for most of the data examples I have replaced all the time sample data with ten samples of INT2 (16bit data)

The Perl script contains numerous tricks of the trade I have learned over the years. Some of them are:

  1. How to automatically determine if a segy is big or little endian (check the sample format)
  2. How to convert IBM float to IEEE float (from SU and Garry Billings at Talisman)
  3. How to convert EBCDIC to ASCII
  4. How to read big or little endian and write out BIG endian on a little endian machine (Linux)
Please feel free to contact the author if you need further clarification. Eric Keyser