SEG-D rev. 3

1. SEG-D rev. 3 Ultra High capacity tapes (3592, IBM TS1120, ....) in the seismic industry SEG Houston 2005 Nils Aatland naatl@online.no

2. My background • 17+ years in the seismic industry (Geco, G-P, WesternGeco) • Recording system • Onboard QC system • Onboard Processing • Automation (Acquisition ---> DP) • Storage Tape: Open Reel, 3480, D2, 3590B/E, LTO, ... Disc: • Tape media • SEG-D Rev 3 co-author (together with Bob Firth, Troika) Funding (SEG-D rev 3):

3. Agenda • References • SEG Denver 2004 • SEG-D revisions vs Tape technologies • EAGE Madrid 2005 • SEG-D Rev 3 / proposed changes • SEG-D Rev 3 / current proposals

4. References • SEG-D rev 2, SEGY, SPS, .... http://seg.org/publications/tech-stand/ • SEG-D rev 3 ftp://ftp.troika-int.com/segfield/ segfield-list@troika-int.com

5. SEG Technical Standards Committee Meeting (SEG Denver Oct 2004) • SEG-D Review Subcommittee Alan Faichney had proposed that this be disbanded due to lack of volunteer effort. Committees were set up two years ago to review and they reported. Then working committees were then set up, however no progress was made. • General feeling that this should not be left to drift and it was proposed that we should go back and solicit input from manufacturers and users and any other interested groups. • Previous revisions to SEG-D were driven by need as a result of manufacturer changes to equipment. (e.g. 3490 to 3590 tapes) • Oil companies would probably support changes that would have value but not just for a few header changes. • The new IBM format tapes might be a big enough change to drive this? • If a new format was to be defined it was important that all stages of the processing business right through to interpretation must be represented. Ted Mariner said it was his responsibility to make sure the support was found and given! • Jill Lewis said this needed a small core group of people working on the format with a wider review group. This was the model used for SEGY Rev 1 and had worked well.

6. SEG-D vs Tape Standards SEG-D rev 0 (1975): The nine track one-half inch tape is retained, but extension to 6250 BPI is permitted as long as it is compatible with the ANSI standard (ANSI 1973a, b, 1976). SEG-D rev 1 (1994): Providing provisions for using 1/2" square tape cartridges. ( ANSI X3.180 1989). SEG-D rev 2 (1996): Since Rev 2 is intended to handle higher density tapes, acceptable media is expanded to include: 3490/3490E, 3590, D2, and D3. SEG-D rev 3 (EAGE Madrid June 2005) It was decided that within the current timeframe and the general desire to take advantage of ultra high capacity media a revision of SEG-D to rev 3.0 is appropriate at the present time.

7. Problem description The stipulation in the 1975 standard that “no more than one line of seismic data is permitted on any one reel” became impractical long ago. SEG-Y rev 1 (May 2002) SEG-D rev 3 (Nov 2005?)

8. Example (marine) - 10 x 6 km streamers (12.5 m group length) - 40 km line length (=1600 shots per line) - 10 sec shot interval - 8 sec record length, 2 msec -------------------------------------------------------------- Format: SEG-D 8015 Amount of data per shot: ~ 50 MB Amount of data per line: ~ 80 GB 3590E: USD 20? / 20 GB / : 1 $/ GB 3592 vs 2 (TS1120): USD 125? / 500 GB : 0.25 $/ GB

9. TCO estimates

10. EAGE Madrid June 2005 • Question SEGD Rev 3.0 or SEGE – vote It was decided that within the current timeframe and the general desire to take advantage of high capacity media a revision of SEGD to rev 3.0 is appropriate at the present time. • Concerns driving the requirement for a Rev 3.0 The receiver count is ever increasing and when this is multiplied by 4 (for four component recording) then the present limit on the number of channel that can be recorded becomes an issue. +++

11. EAGE Madrid June 2005 • Critical Items and volunteer companies who will present the working group (reflector site members) with their recommendations: 4C - Western Geco / Veritas / Sercel / IO Channel Set Descriptors XYZ+Time - Concept / Saudi Aramco / Sercel / SPS Compatibility File Numbers and Multiple Lines - Troika/ Verify / Western Geco Blocking + Non-blocking & Separate Layers • The challenge to the group is to come up with a draft set of documents to be handed to Ted Mariner by 1st October.

12. SEG-D rev 2 - 1996 The subcommittee consisted of the following individuals: • George Wood Western Geophysical / Chairman • Phil Behn Input/Output • Claes Borresen PGS • William Guyton Western Geophysical • Louis Miles Syntron • Dennis O‘Neill Geco-Prakla • Sut Oishi Shell • Tony Scales Sercel

13. Rev 3 proposed ’changes’ (1:39) Issue Status Resp. Deadline Comment ------------------------------------------------------------------------------ Update ftp server - Bob Nov 15’th .... New input - All Dec 15'th …. Chapter 1 (Intro) - Jill Jan 1'st …. Chapter 2 - - Jan 1’st ..... 1: - - - …. 2: - - - …. . . 39 - - - ….

14. SEG-D rev 3App F: Maximum Block Sizes The table below indicates the maximum allowable block size for accepted types of media. It is expected that this table will need to be updated approximately once per year. Device Type Maximum Block Size 3480 128 Kilobytes 3490, 3490E 256 Kilobytes 3590 512 Kilobytes IBM 3592 (Jaguar-1) 2,097,152 Bytes (2 Megabytes) IBM TS1120 (Jaguar-2) 2,097,152 Bytes (2 Megabytes) DST1, 199,840 Bytes Redwood 256 Kilobytes STK 9940B 256 Kilobytes 1/2” Round Tape 64 Kilobytes • Kilobyte is defined as 1024 bytes • Megabyte is defined as 1024x1024 bytes (=1,048,576 bytes)

15. SEG-D rev 3App C: API codes • Rev 3 (One simple question: Address correct?) • POSC  24 Greenway Plaza • Suite 1000-B  Houston, TX 77046  USA • +1 713 784-1880  telephone • +1 713 784-9219  fax • info@posc.org • http://www.posc.org/ • Rev 2 (No longer correct) • American Petroleum Institute • Exploration and Production Department • 1220 L Street, N. W. • Washington, D.C. 20005 • Phone: (202) 682‑8000 • FAX: (202) 682‑8426

16. Appendix A: Manufacturers of Seismic Field Recorders 40 Geo-X 1996 Suite 900, 425 1st St SW Calgary, Alberta, Canada T2P3L8 41 PGS ??? 42 ??? 43 Hydroscience ???

17. Appendix G: Multiple SEG-D header blocks • Proposal (If SEG-D header is longer than maximum physical block size). • N-1 header blocks with fixed size, block number N without padding: • By reading and decoding the very first 64 bytes (GH #1 and GH #¤ 2), it’s possible to calculate the total SEG-D header length. If block size and total SEG-D header length are known, it’s possible to calculate number of physical tape header blocks. • Feedback wanted.

18. Rev 2 BOT Tape label 128 bytes / Required General Header # 1 / ” General Header # 2 / ” General Header # N / Optional (N>2)

19. Rev 3 BOT Tape label 128 bytes / Required EOF?? General Header # 1 / ” General Header # 2 / ” General Header # 3 / ” Vessel/Crew General Header # 4 / ” Area General Header # 5 / ” Client General Header # 6 / ” Job General Header # 7 / ” Line General Header # N / Optional (N>7)

20. SEG-D rev 3 proposals We recommend to introduce 5 new required General Header blocks (#3,#4,#5,#6,#7) due to multiple lines. • Vessel/crew identification (with abbreviation?) ASCII*32 ? • Area name (with abbreviation?) ASCII*32 ? • Client name (with abbreviation?) ASCII*32 ? • Job name (with abbreviation?) ASCII*32 ? • Line name ASCII*16 ? Is it possible to get an agreement how to generate line name? [Area:2][Client:2][year:2][line type:1][linenumber:4]-[sequence:4] WGecoTape LabelSerial number: [vessel:2][job:4][reel number:6]

21. Proposal for discussion: New required GH blocks #3-#7 1 byte block ID, 0/2/4 bytes abbreviation (ASCII) 26-28 bytes ASCII and 1 byte status • ID Abbreviation Comment Example • 01 SE Crew Id Sea Explorer • 02 NS Area Name North Sea - Statfjord • 03 ST Client Statoil • 04 8104 Job WesternGeco 8104 • 05 Line Name ST05-12543-001 Status Codes: 0x01 OK 0x02 Not OK, e.g. data in this header block are not valid 0x03 Irrelevant