Version 1

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Welcome
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Acquisition
Interpretation
Processing
Mumbai
SR, Chennai
GEOPIC
Under NELP, there are Multiple EP Operators
HampsonRussel
Paradigm
GF-Charisma
GF- IESX
SeisWorks
SeisWorks
Project D
Project C
Project C
Project E
Project B
Project D
Project G
Project H
Project A
Project F
Version 3
Version 1
Version 3
Version 2
Version 2
Version 1
Version 2
Version 1
Version 1
Confused?
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Accounting of Recording delays
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• Interpretation related
• Seismic data loading application should also read
  X, Y coordinates along with SP/Line CDP/Trace
• If X, Y coordinates are different from Seismic
  Project, then the application should throw a
  warning message. This is to prevent wrong data to
  be loaded
• Interpreted data must seamlessly be accessible
  across various platforms, various third party
  applications
• Is there any Standard way to exchange
  interpretation data?

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The need for Standards for exchange of seismic
trace and velocity data was deliberated and the
following opportunities were identified and work
initiated. The first high value opportunity
identified was Velocity Data. This opportunity
was rated with High Impact and Low Effort. The
Velocity Data team includes geophysicists from
ONGC, RIL, and WesternGeco. A second high value
opportunity was identified to be ONGC-defined
Extended SEG-Y Header Data. This opportunity was
rated with Medium Impact and Low Effort. The
Extended SEG-Y Header Data Team includes
geophysicists from ONGC, GSPC, and CGG Veritas.
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No information about the Cartographic Reference
System
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No information about the Cartographic Reference
System
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Shot CDP relation ?
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SHOT Point Range in Navigation in SPS format and
Trace Headers do not match
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X,Y coordinates in trace header do not correspond
to the CMP location.
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Velocity format is proprietary to processing
company
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Information about 3D grid and Cartographic
reference available. However the scalar
indicated in Text Header is not updated in Trace
Headers
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The scalar to coordinates should have been -100
instead of 1
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The Examples are Innumerable. ONGC has already
taken initiative in standardizing Content and
lay out of Text Header and Minimum locations to
be updated in Binary and Trace Headers for post
stack data for loading in IIWS Additional
requirements as perceived by other companies
(at least in Indian Context) can be included and
finalized. It is suggested to use the SEGY Text
layout as used in ONGC and insist that the data
be supplied/exchanged accordingly. The Header
information in SEGY as practiced in ONGC is
provided in the next few slides.
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EBCDIC Header Standardization C 1 CLIENT OIL
AND NATURAL GAS CORPORATION LIMITED. 2D SEISMIC
DATA C 2 LINE M125-02
SURVEY xxxxxxxxxxxxxxxx AREAxxxxxxxxxxxxxxxxxx
C 3 SPHEROID EVEREST75 PROJECTIONUTM-44
CM 81 CP2 XX C 4 FSP
74 IS AT LAT 11 12 18.12 N LON 79
30 29.01 E C 5 LSP 1088 IS
AT LAT 11 01 26.84 N LON 79 20 42.52 E
C 6 FCDP 1 SP ON FCDP 1
LCDP 1088 SP ON LCDP 1088 C 7 ADDITIONAL
SP CDP RELATION PAIRS FOR CROOKED PROFILE
(OTHERWISE BLANK) C 8 ADDITIONAL SP CDP
RELATION PAIRS FOR CROOKED PROFILE (OTHERWISE
BLANK) C 9 BLANK
C10
ACQUISITION PARAMETERS
C11 RECORDING YEAR
2004 AGENCYONGC
VESSEL/PARTYGP-29 C12 SYSTEMDFS-IV
REC FORMATSEG-B
LOW/HIGHCUT 8/128 HZ C13 NO OF
CHANNELS 96 FOLD 48
SOURCE VIBROSEIS C14 SAMPLE
INTERVAL 2MS REC LENGTH 5000 MS REC
START TIME 0MS C15 SHOT INTERVAL 100 M
GROUP INTERVAL 100 M NEAR OFFSET 200 M
C16 LAYOUTSPLITSPREAD BACK CHANNELS 72
FORWARD CHANNELS 24 C17 ENTER
ADDITIONAL INFORMATION HERE
C18 ENTER ADDITIONAL
INFORMATION HERE
C19 BLANK
C20
PROCESSING PARAMETERS AGENCY RCC, CHENNAI, ONGC
BASIC/REPROCESSING C21 to C34 PROCESSING
STEPS C35 BLANK
C36 PROCESSED OUTPUT STORED
IN THIS TAPEDMOSTK/MISTK/PSTM/PSDM
C37 DOMAINTIME/DEPTH REC LENGTH 4000
MS SAMPLE INTERVAL 4 MS C38 ADDITIONAL
INFORMATION C39 BLANK
C40
END EBCDIC
 
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EBCDIC HEADER FOR 3D
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MANDATORY LOCATIONS TO BE UPDATED IN BINARY
HEADER as per SEGY Rev 1 17 - 18 SAMPLE
INTERVAL IN MICRO SECONDS. (not milliseconds) 21
- 22 NUMBER OF SAMPLES PER DATA TRACE. 25 -
26 DATA SAMPLE FORMAT CODE. 1 IBM FLOAT,
3-16 BIT INTEGER 27 - 28 EXPECTED NUMBER OF
TRACES PER ENSEMBLE. 1 FOR POST STACK DATA. 29
- 30 TRACE SORTING CODE. 4 FOR STACK
DATA 55 - 56 MEASUREMENT SYSTEM. 1 FOR
METERS 2- FEET 301 - 302 SEGY FORMAT REVISION
NUMBER SHOULD BE 0 303 - 304 FIXED TRACE
LENGTH FLAG. SHOULD BE 0 305 - 306
EXTENDED TEXTUAL FILE HEADER RECORDS AFTER BINARY
HEADER.
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MANDATORY LOCATIONS IN TRACE HEADER as per SEGY
Rev 1 1 - 4 TRACE SEQUENCE NUMBER
WITHIN THE LINE 21 - 24 CDP NUMBER 29 -
30 TRACE IDENTIFICATION CODE. 1 FOR SEISMIC
DATA 71 - 72 SCALAR TO BE APPLIED TO
COORDINATES IN 181-188 TO GET REAL VALUE. IF
VE, SCALAR IS USED AS MULTIPLIER
IF -VE, SCALAR IS USED AS DIVISIOR.
1 IF X,Y ARE GIVEN IN METERS. 115 - 116
NUMBER OF SAMPLES IN THIS TRACE 117 - 118 SAMPLE
INTERVAL IN MICRO SECONDS FOR THIS TRACE. 181 -
184 X COORDINATE OF THIS TRACE I85 - 188 Y
COORDINATE OF THIS TRACE 189 - 192 INLINE 193 -
196 X-LINE 197 - 200 SHOTPOINT NUMBER FOR THIS
TRACE 201 - 202 SCALAR TO BE APPLIED TO THE SHOT
POINT NUMBER IN 197-200. IF 0,
THE SHOT POINT IS TAKEN AS SUCH.
IF VE, SCALAR IS USED AS MULTIPLIER
IF -VE, SCALAR IS USED AS DIVISIOR.
EXAMPLE IF SHOT POINT ABOVE CDP 101 IS
50.5, IT SHOULD BE STORED AS 505
IN LOCATIONS 197-200 AND -10 AS SCALAR IN
LOCATION 201-202
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• Velocity formats
• VELF, Handvel, CGG, Promax, TDQ, GEOQUEST,.
• All are ASCII but the fields are different
• Most Interpretation S/W require strict adherence
  to their formats of velocities without any
  tolerance (any extra column is not acceptable)
• An ASCII format for velocity picks with
• inline, xline, x-cord, y-cord, time and velocity
  may be acceptable
• (for 2D, Line name and SP instead of inline,
  xline)
• The header should contain type of Velocity
  (Stack, Average or Migrated), Vertical axis (TWT,
  Depth, ) and units of measurement.
• The velocities are to be adjusted relative to
  seismic datum
• Cartographic Reference
• Description of seismic investigation from which
  the velocities are derived

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No indication of what velocity type is stored in
the file. One has to check the functions and
understand. In the last example, it should be
interval velocity. Some times the file name
gives indication of the type as is the case with
the next example. However, the velocity loading
modules do not know it and sets them as default
type of velocity functions internally
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• A lot of space is either blank or used for
  repetitive Id ,X, Y values.
• Editing the interpolated velocity functions or
  Velocity functions given as SEGY traces is
  impractical.
• Original picks are to be provided invariably.
• We may agree upon the content and mnemonics for
  the fields and XML based format that only
  contains the values for the fields to reduce the
  file size.
• inline, xline, x-cord, y-cord, time and velocity
  may be acceptable
• (for 2D, Line name and SP instead of inline,
  xline)
• The header should contain type of Velocity
  (Stack, Average or
• Migrated), Vertical axis (TWT, Depth,) and
  units of measurement.
• The velocities are to be adjusted relative to
  seismic datum
• Cartographic Reference
• Description of seismic investigation from which
  the velocities
• are derived

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Thank You for Your Time