SEG Technical Standards Committee SEG-D Revision 3.0 Proposal

SEG Technical Standards CommitteeSEG Technical Standards Committee

SEG-D Revision 3.0 ProposalSEG-D Revision 3.0 Proposal

SEG Field Tape Standards HistorySEG Field Tape Standards History

1967SEG-A & SEG-B

SEG-C 1972

SEG-D Rev 0 1979

Rev 11994

SEG-D, Rev 2.1 SEG Field Tape Standards

2006

Rev 2 1996

The 2006 2.1 revision was specifically designed as a targeted upgrade to support very high capacity tapes.

3.0 was promised in the 2.1 standard to follow soon afterwards and deal with major overhaul and/or upgrades.

The 2006 2.1 revision was specifically designed as a targeted upgrade to support very high capacity tapes.

3.0 was promised in the 2.1 standard to follow soon afterwards and deal with major overhaul and/or upgrades.

Why now?Why now?

Jill Lewis (Troika International)

— Earns living transferring & transcribing data

Stewart A. Levin (Halliburton Energy Services)

— ProMAX™ SEG-D Input support & upgrades

Rune Hagelund (WesternGeco)

— Umpteen years acquisition software

experience

Barry D. Barrs (ExxonMobil)

— Navigation and positioning expertise

Jill Lewis (Troika International)

— Earns living transferring & transcribing data

Stewart A. Levin (Halliburton Energy Services)

— ProMAX™ SEG-D Input support & upgrades

Rune Hagelund (WesternGeco)

— Umpteen years acquisition software

experience

Barry D. Barrs (ExxonMobil)

— Navigation and positioning expertise

Why us?Why us?

• An explosion in data being stored in vendor-specific headers driven by the need for smooth transfer between acqusition & QC/processing

• Multicomponent surveys

• Higher sampling rates/non-power-of-2 ratios

• Beyond 24-bit sensor sensitivity

• Continuous passive monitoring

• Only non-record format is long byte stream— cumbersome for QC and transcription

• An explosion in data being stored in vendor-specific headers driven by the need for smooth transfer between acqusition & QC/processing

• Multicomponent surveys

• Higher sampling rates/non-power-of-2 ratios

• Beyond 24-bit sensor sensitivity

• Continuous passive monitoring

• Only non-record format is long byte stream— cumbersome for QC and transcription

SEG-D issues driving 3.0SEG-D issues driving 3.0

• Nonseismic data?

• Positioning standards coordination

• Using web documents for dynamic information– Manufacturer list

– Media types and parameters

– API organization codes

– Guidance recommendations and clarifications

– Errata and translations

• Format validation utilities

• Nonseismic data?

• Positioning standards coordination

• Using web documents for dynamic information– Manufacturer list

– Media types and parameters

– API organization codes

– Guidance recommendations and clarifications

– Errata and translations

• Format validation utilities

SEG-D opportunities driving 3.0SEG-D opportunities driving 3.0

• All features discussed at SEG New Orleans have been implemented– With a few additions

• SEGD Tape Label, General Header 1 and Demux Trace Header left as is (with a few exceptions)

• Be an efficient format for transferring information between acquisition and QC/processing– SEGD is not a processing format

• More space for user-defined header blocks

• All features discussed at SEG New Orleans have been implemented– With a few additions

• SEGD Tape Label, General Header 1 and Demux Trace Header left as is (with a few exceptions)

• Be an efficient format for transferring information between acquisition and QC/processing– SEGD is not a processing format

• More space for user-defined header blocks

Overview of revision 3.0 proposalOverview of revision 3.0 proposal

• Increased flexibility– Header blocks tagged to allow shot specific (attached

to general header) or trace specific information

– Flexible sample rates, header sizes, reclength etc.

• Increased robustness– Tagged header blocks

– Size of shot/data in General Header

• Simplified encoding/decoding – No complex datatypes, using 4byte float, int etc

– Explicit values (ex. #samples/trace)

– No dependencies between header blocks

• Additional functionality

• Increased flexibility– Header blocks tagged to allow shot specific (attached

to general header) or trace specific information

– .Flexible sample rates, header sizes, reclength etc

• Increased robustness– Tagged header blocks

– Size of shot/data in General Header

• Simplified encoding/decoding– No complex datatypes, using 4byte float, int etc

– Explicit values (ex. #samples/trace)

– No dependencies between header blocks

• Additional functionality

Overview of revision 3.0 proposalOverview of revision 3.0 proposal

• Logical numbering of traces/source points extended to handle all operation types– Line number

– Point number

– Point index

– Group index

– Depth index

– Reshoot index

• Logical numbering of traces/source points extended to handle all operation types– Line number

– Point number

– Point index

– Group index

– Depth index

– Reshoot index

New features in revision 3.0 proposalNew features in revision 3.0 proposal

• Support for complex shooting schemes– Multiple source initiations per shot record

– Multiple sources firing simultaneously

• Support for complex source configurations– Traces and measurements for sources and parts of

sources

• Align SEG-D with SPS standard and/or SEG-Y revision 1 positioning support

• Support for complex shooting schemes– Multiple source initiations per shot record

– Multiple sources firing simultaneously

• Support for complex source configurations– Traces and measurements for sources and parts of

sources

• Align SEG-D with SPS standard and/or SEG-Y revision 1 positioning support


• Standardizing storage of common survey information– Vessel/crew identification

– Survey area name

– Client identification

– Job identification

– Line identification (Record set ID)

• Size of record, data, and headerexplicit in General Header

• Standardizing storage ofcommon survey information– Vessel/crew identification

– Survey area name

– Client identification

– Job identification

– Line identification (Record set ID)

• Size of record, data, and header explicit in General Header


• Positions can be tagged to all traces/equipment– Multiple positions (in space and time)

– Format TBD by pos group

• Support for multi-component data– Node number, trace grouping, orientation header

• New General Trailer format– Flexible, allows any data-block to be appended

• Standardized edits can be appended to GeneralTrailer– Allows easy addition of edits post-acquisition

• IEEE 8 byte samples :8068

• Positions can be tagged to all traces/equipment– Multiple positions (in space and time)

– Format TBD by pos group

• Support for multi-component data– Node number, trace grouping, orientation header

• New General Trailer format– Flexible, allows any data-block to be appended

• Standardized edits can be appended to General Trailer– Allows easy addition of edits post-acquisition

• 8068: IEEE 8 byte samples


• Sample rate steps of 1 microsecs

• No longer a base scan rate– Dominant sample interval used for backwards

compatibility

• Timestamp – counting microsecs since 6 Jan 1980 (GPS epoch)– byte integer 8

– Negative timestamps allowed

– years range 292471

• Sample rate steps of 1 microsecs

• No longer a base scan rate– Dominant sample interval used for backwards

compatibility

• Timestamp – counting microsecs since 6 Jan(GPS epoch) 1980– 8 byte integer

– Negative timestamps allowed

– 292471 years range

Sample rate / timestampSample rate / timestamp

• All measurements now properly tagged with accurate, absolute timestamp (if available)– .Positions, traces, shot, etc

• All header sizes extended– More room for acquisition system defined blocks

– ....Existing trace ext hdr blocks may be used

– but remember to use correct block tag...

• Standardizing storage of SEGD– One header block spanning multiple tape blocks

– A trace spanning multiple tape blocks

– Fixed/variable block devices

– Disk storage

– Transfer across network

• All measurements now properly tagged withaccurate, absolute timestamp (if available)– Positions, traces, shot, etc.

• All header sizes extended– More room for acquisition system defined blocks

– Existing trace ext hdr blocks may be used....

– ...but remember to use correct block tag

• Standardizing storage of SEGD– One header block spanning multiple tape blocks

– A trace spanning multiple tape blocks

– Fixed/variable block devices

– Disk storage

– Transfer across network


• More sensor types/channel types explicitly supported– Wind, depth, reference signals, source measurements

etc.

• Sensor sensitivity value stored per channel– Convert to actual physical unit

– Support non-voltage measurements

• More sensor types/channel types explicitly supported– Wind, depth, reference signals, source measurements

etc.

• Sensor sensitivity value stored per channel– Convert to actual physical unit

– Support non-voltage measurements


• Table Of Contents file– Stored at end (or beginning) of tape

– Lists all SEGD records on a tape

– Enable fast access to data

– May be stored on disk (to simplify data mgt)

• Table Of Contents file– Stored at end (or beginning) of tape

– Lists all SEGD records on a tape

– Enable fast access to data

– May be stored on disk (to simplify data mgt)


• Line number -> Record set number– To be usable for all types of operation

• Only 3 General Header blocks required in rev 3.0– Everything else optional

• Line number -> Record set number– To be usable for all types of operation

• Only 3 General Header blocks required in rev 3.0– Everything else optional


• Channel set header block 96 bytes

• Header block sizes– General header - 65536 blocks (2 MB)

– Channelset header – 65535 blocks (~6MB)– Skew blocks – 65535 blocks (~2MB)– Extended header – 16777215 blocks (~512MB)– External header - 16777215 blocks (~512MB)– Trace Header Extension – 255 blocks (8160 bytes)

– General Trailer – 4294967295 blocks (~128GB)

• Channel set header block 96 bytes

• Header block sizes– General header - 65536 blocks (2 MB)

– Channelset header – 65535 blocks (~6MB) – Skew blocks – 65535 blocks (~2MB)– Extended header – 16777215 blocks (~512MB)– External header - 16777215 blocks (~512MB)– Trace Header Extension – 255 blocks (8160 bytes)

– General Trailer – 4294967295 blocks (~128GB)

Header size extensionsHeader size extensions

• Traces can be 2147 seconds long

• Negative start times allowed

• Extended recording mode allows up to 140,735,340 seconds (1628 days) of data to be stored in one record

• Traces can be 2147 seconds long

• Negative start times allowed

• Extended recording mode allows up to 140,735,340 seconds (1628 days) of data to be stored in one record

Trace sizeTrace size

• Extended filter definitions– Frequencies and slopes are IEEE floats (4 bytes)

– Filter type

– Filter delay

• Extended filter definitions– Frequencies and slopes are IEEE floats (4 bytes)

– Filter type

– Filter delay

FiltersFilters

• Volunteers always wanted– We’re taking names

– Multicomponent standards

– Downhole acquisition support

– Metadata additions (temperature, wave height, …)

• Opinions too – We’re taking notes

• Volunteers always wanted– We’re taking names

– Multicomponent standards

– Downhole acquisition support

– Metadata additions (temperature, wave height, …)

• Opinions too – We’re taking notes

Questions, Concerns and Suggestions?Questions, Concerns and Suggestions?

Documents

SEG Technical Standards Committee SEG-D Revision 3.0 Proposal