brazil southern basin psdm spec - tgs€¦ · brazil southern basin psdm pre stack depth migration...

Offshore Brazil Brazil Southern Basin PSDM PRE STACK DEPTH MIGRATION MULTI-CLIENT 2D SURVEY ACQUISITION PARAMETERS Acquisition Date: July 1999 – June 2001 April 1999 – June 2001 Data Acquired By: TGS-NOPEC GECO-PRAKLA Shooting Orientation: 2D basin strike and dip 2D basin strike and dip Recording Instrument: Hydroscience Seamux 2000 Triacq Streamer Positioning: GPS GPS Streamer type: Digital HTI Nessie 4 Airgun Source: 5000 cubic inches 7918 cubic inches Gun Depth: 6m 6m Shotpoint Interval: 37.5m 37.5m Group Interval: 25m 25m Recording Channels: 324 320 Streamer Depth: 7m 7m Streamer Length: 8100m 8000m Record Length: 12s 12s Sample Interval: 2ms 2ms Nominal Fold: 108 106 PROCESSING SEQUENCE Depth Migration by: TGS-Depth Imaging - Houston, TX- (2007-2010) Input Radon SEGY data processed by TGS-NOPEC and Geco-Prakla Initial sediment velocity model: velocity field from the PSTM after removing salt and smoothing Kirchhoff depth migration / Tomography update Kirchhoff depth migration / Tomography update if carbonate present above salt Kirchhoff depth migration / Interpret top of salt Wave equation shot domain migration / Interpret base of salt Iterate top and base salt interpretation/migration as necessary for multiple salt bodies and overhangs Output top and base salt horizons Kirchhoff depth migration / subsalt Tomography Output PSDM migration velocity model Final shot domain wave equation and offset domain Kirchhoff depth migrations Final Migration parameters: Output CDP Distance: 25 meters Maximum Frequency: 45 Hz WEM, 75 Hz Kirchhoff Total Depth: 16,000 meters Final Depth Step: 5 meters Output Kirchhoff migrated gathers with NMO Interpolate to 12.5 meters Output raw WEM and Kirchhoff migration Time-variant filtering /TV balance / F-X deconvolution - output processed WEM and Kirchhoff migration AVAILABLE DELIVERABLES Field data with 2D geometry / shot ordered Radon de-multiple CDP gathers Pre-stack Kirchhoff depth migrated gathers with NMO - (in depth – m or ft) *Pre-stack depth migration- Raw – 12.5m (in depth – m or ft) *Pre-stack depth migration- Processed - 12.5m (in depth – m or ft) *PSDM converted to time- Processed – 12.5m Final velocity volume- 12.5m (in depth – m or ft) SEGY Sediment velocity volume- 12.5m (with sub salt tomo - in depth – m or ft) SEGY Interpreted top of salt horizon (includes TOS1+TOS2 - ASCII – m or ft) Interpreted base of salt horizon (includes BOS1+BOS2 - ASCII – m or ft) Interpreted water bottom horizon (ASCII – m or ft) Post stack navigation – UKOOA *Wave Equation and Kirchhoff versions available February 7, 2014

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Offshore BrazilBrazil Southern Basin PSDM

PRE STACK DEPTH MIGRATION MULTI-CLIENT 2D SURVEY

ACQUISITION PARAMETERS Acquisition Date: July 1999 – June 2001 April 1999 – June 2001

Data Acquired By: TGS-NOPEC GECO-PRAKLA Shooting Orientation: 2D basin strike and dip 2D basin strike and dip

Recording Instrument: Hydroscience Seamux 2000 Triacq Streamer Positioning: GPS GPS

Streamer type: Digital HTI Nessie 4 Airgun Source: 5000 cubic inches 7918 cubic inches

Gun Depth: 6m 6m Shotpoint Interval: 37.5m 37.5m

Group Interval: 25m 25m Recording Channels: 324 320

Streamer Depth: 7m 7m Streamer Length: 8100m 8000m

Record Length: 12s 12s Sample Interval: 2ms 2ms

Nominal Fold: 108 106

PROCESSING SEQUENCE Depth Migration by: TGS-Depth Imaging - Houston, TX- (2007-2010)

Input Radon SEGY data processed by TGS-NOPEC and Geco-Prakla Initial sediment velocity model: velocity field from the PSTM after removing salt and smoothing Kirchhoff depth migration / Tomography update Kirchhoff depth migration / Tomography update if carbonate present above salt Kirchhoff depth migration / Interpret top of salt Wave equation shot domain migration / Interpret base of salt Iterate top and base salt interpretation/migration as necessary for multiple salt bodies and overhangs Output top and base salt horizons Kirchhoff depth migration / subsalt Tomography Output PSDM migration velocity model Final shot domain wave equation and offset domain Kirchhoff depth migrations

Final Migration parameters: Output CDP Distance: 25 meters Maximum Frequency: 45 Hz WEM, 75 Hz Kirchhoff Total Depth: 16,000 meters Final Depth Step: 5 meters

Output Kirchhoff migrated gathers with NMO Interpolate to 12.5 meters Output raw WEM and Kirchhoff migration Time-variant filtering /TV balance / F-X deconvolution - output processed WEM and Kirchhoff migration

AVAILABLE DELIVERABLES Field data with 2D geometry / shot ordered Radon de-multiple CDP gathers Pre-stack Kirchhoff depth migrated gathers with NMO

- (in depth – m or ft) *Pre-stack depth migration- Raw – 12.5m (in depth – m or ft) *Pre-stack depth migration- Processed - 12.5m

(in depth – m or ft) *PSDM converted to time- Processed – 12.5m

Final velocity volume- 12.5m (in depth – m or ft) SEGY Sediment velocity volume- 12.5m (with sub salt tomo

- in depth – m or ft) SEGY Interpreted top of salt horizon (includes TOS1+TOS2

- ASCII – m or ft) Interpreted base of salt horizon (includes BOS1+BOS2

- ASCII – m or ft) Interpreted water bottom horizon (ASCII – m or ft) Post stack navigation – UKOOA

*Wave Equation and Kirchhoff versions available February 7, 2014