SPS 3.0

Update of the Progress of the SPS Subgroup of the SEG Technical Standards Committee

Cignoli, J.E.; Green, P.C.; Hubbell, S.E.; Moffitt, R.G.; Siddiquee, F; Bowes, A.W.; LaFon, S.K.; Musser, J.A. (Saudi Aramco) September, 2011

Current SPS v2.1 Point Record (R & S) Specifications

Item 1 2 3 + 4 5 6 7 8 9 10 11 12 13 14 15 Definition of field

Record identification Line name Point number Point index Point code Static correction Point depth Seismic datum Uphole time Water depth Map grid easting Map grid northing Surface elevation Day of year Time “hhmmss”

Cols

1-1 2-11 12-21 22-23 24-24 25-26 27-30 31-34 35-38 39-40 41-46 47-55 56-65 66-71 72-74 75-80

Format

A1 F10.2

F10.2

I1 A2 I4 F4.1

I4 I2 F6.1

F9.1

F10.1

F6.1

I3 3I2

Min. to max

“S” or “R” -999999.99 to 9999999.99

-999999.99 to 9999999.99

1 to 9 A# -999 to 9999 0 to 99.9

-999 to 9999 0 to 99 0 to 9999.9

None None -999.9 to 9999.9

1 to 999 000000 to 235959 0 0 Blank Blank None None None None None

Default

None None None Blank 1 None Blank

Just.

n/a Right Right Right Left Right Right Right Right Right Right Right Right Right n/a Blank

units

ms Header defined Header defined ms Header defined Header defined

Proposed SPS v3.0 Point Record (R & S) Specifications

+ 4 5 6 7 8 9 10 11 12 13 14 Item 1 2 3 Definition of field

record identification line name point number

Cols

1-1 2-17 18-33

Format

A1 F16.5

F16.5

Min. to max

“S” or “R” -999999999.99999 to 9999999999.99999

-999999999.99999 to 9999999999.99999

Default

None None None

Just.

n/a Right Right

units

point index point code point depth tide height water depth 34-35 36-38 39-41 42-49 50-54 55-62 I3 A3 F8.2

F5.2

F8.2

1 to 999 A## 0 to 99999.99

-9.99 to 99.99

0 to 99999.99

Blank 1 None 0 0 Blank Right Left Right Right Right Blank Header defined Header defined Header defined map grid easting map grid northing surface elevation 63-72 73-83 84-91 F10.2

F11.2

F8.2

None None -9999.99 to 99999.99

None None None Right Right Right Header defined day of year (Julian day) time “hhmmss” 92-94 95-100 I3 3I2 1 to 999 000000 to 235959 None None Right n/a GPS time* (SEGD Timestamp) 101-121 F21.6

-9223372036854.123456 to 9223372036854.123456

None Right Seconds

* The GPS Time / SEGD Timestamp is the time in seconds with microsecond precision since 06 January 1980 00:00:00 (GPS epoch).

Dates and times before 06 January 1980 will have a negative GPS Time value.

Current SPS v2.1 Relation Record (X) Specifications

10 11 12 13 14 15 Item 1 2 3 4 5 6 7 8 9 Definition of field

Record identification Field tape number Field record number Field record increment Instrument code Line name Point number Point index From channel To channel Channel increment Line name From receiver To receiver Receiver index

Cols

1-1 2-7 8-15 16-16 17-17 18-27 28-37 38-38 39-43 44-48 49-49 50-59 60-69 70-79 80-80

Format

A1 3A2 I8 I1 A1 F10.2

F10.2

F4.1I1

I5 I5 I1 F10.2

F10.2

F10.2

I1

Min. to max

“X” free 0 to 16777215 1 to 9 1 to 9 -999999.99 to 9999999.99

999999.99 to 9999999.99

1 to 9 1 to 99999 1 to 99999 1 to 9 999999.99 to 9999999.99

999999.99 to 9999999.99

999999.99 to 9999999.99

1 to 9

Default

None None None 1 1 None None 1 None None Blank1 None None None 1 n/a right right right right right right right right right right right right right right

Just.

Proposed SPS v3.0 Relation Record (X) Specifications

10 11 12 13 14 15 Item 1 2 3 4 5 6 7 8 9 Definition of field

record identification field tape number field record number field record increment instrument code source line name source point number source point index from channel number to channel number channel number increment receiver line name from receiver point number to receiver point number receiver point index 1-1

Cols

2-13 14-21 22-23 24-24 25-40 41-56 57-59 60-66 67-73 74-76 77-92 93-108 109-124 125-127

Format

A1 6A2 I8 I2 A1 F16.5

F16.5

I3 I7 I7 I3 F16.5

F16.5

F16.5

I3

Min. to max

“X” free 0 to 16777215 1 to 99 1 to 9

Default

None None None 1 1 -999999999.99999 to 9999999999.99999 None -999999999.99999 to 9999999999.99999 None 1 to 999 1 to 9999999 1 None 1 to 9999999 1 to 999 None 1 -999999999.99999 to 9999999999.99999 None -999999999.99999 to 9999999999.99999 None -999999999.99999 to 9999999999.99999 None 1 to 999 1 n/a right right right right right right right right right right right right right right

Just.

• • • • • •

SPS 3.0 Considerations and Features

SPS v3.0 should be fully compatible with SEGD v3.0.

Proposed SPS v3.0 records all require less than 150 columns (as recommended by OGP) and still have room for expansion before that limit is reached.

SEGD supports Short Mother Records (SMR), in which multiple source events are recorded in a single record, resulting in a many-to-one relation of source point records to an ffid on tape.

This will require further generalization of the relational (X) records to allow generation of daughter records with unique ffids from the mother record.

–

This may be a new record or file type (similar to X) or

–

It may be a modification of the existing Relational (X) file with added records defining the daughter data Additional input relating to handling SMRs and subsequent separated daughter records is solicited from industry participants. The current recommendations are Aramco-centric mainly because we have received little feedback from seismic industry service providers when solicited. GPS time with microsecond fidelity is added to allow accurate source separation in high-productivity acquisition (such as ISS).

• • • • • •

SPS 3.0 Considerations and Features

(cont.)

Comma delimiting of record entries is being considered to improve robustness of the formats. [Comma-Space] delimiting is also being considered to help keep the records relatively easy to scan by eye. OBC data acquisition easily fits within the proposed SPS 3.0 definitions.

Current and Future High-Channel Count crews require the SEGY format to increase the current channel limitation (32,767) to be compatible with SEGD (16,777,215).

Consideration should be given in future versions of all formats (SPS, SEGD, SEGY, etc.) for robust handling of Common Receiver Gather data, such as acquired by nodes and other wireless systems.

–

For SPS files, this can be achieved by a reversal of the roles of S and R stations within the X files. Further development of SPS Header Blocks and Templates for specific acquisition technologies and schemes (such as, surface sources, explosives, airgun arrays, buried receivers, seabed receivers, etc.) are under development.

Documentation will proceed upon approval of proposed formats.