Transcript Slide 1

SEG Post-Convention Workshop
SEAM Phase 1: Initial results
Technical and Operational Overview of the
SEAM Phase I Project
Michael Fehler
SEAM Mission
Advance the science and technology of applied
geophysics through a cooperative industry effort
focused on subsurface model construction and
generation of synthetic data sets for geophysical
problems of importance to the resource
extraction industry.
What Do We want to
Accomplish?
• State-of-the-art geophysical numerical modeling
• Develop datasets for testing geophysical imaging and
characterization techniques
• First model is Deepwater Gulf of Mexico
– Subsalt
– Variable-density acoustic and other geophysical datasets
• SEAM Phase I (This talk)
• SEAM RPSEA (Talk at 3:15)
SEAM Operation
• Board of Directors (BOD)
– Bill Abriel, Chair
– Broad overview focused on future of SEAM and
SEAM/SEG relationship
• Management Committee (MC)
– Kevin Bishop, Chair
– Each participating company has one vote
– Make project-specific decisions
• Steve Danbom is liaison between BOD and MC
SEAM Technical Organization
• 6 Technical Committees composed of members from
participating companies
– Define and implement objectives and work plans
– Program Manager coordinates work by and among committees
• Communication through regular meetings and
e-community
– Technical committee co-chairs meet ~monthly
– Management Committee meets quarterly
• One member from each participating company
• Decision making body
SEAM Technical Committees
and Co-Chairs
• Model Design Committee
– Joe Stefani and Richard Day
• Numerical Design Committee
– Scott Morton and John Anderson with help from Bill Symes
• Acquisition Design Committee
– Chuck Meeder and Adam Seitchik
• NonSeismic
– Michael Frenkel and Neville Barker
• Execution Committee
– Peter Wang and Dan Ebrom
• Data Storage and Distribution Committee
– Stew Levin
SEAM Vendors
• Numerical Simulations done by Tierra Geophysical
– Careful evaluation prior to selection by Vendor Qualification
Process
• Quality Control done on simulations by Nexus
Geosciences Inc.
– QC procedure to evaluate quality and reliability of data
delivered by Tierra Geophysical
– Regularly communicate and report to Project Manager
• Data Storage & Distribution done by Landmark
Graphics
– Data are stored in compressed format (10:1 compression)
– Delivery of either compressed or uncompressed data
– Will store model files, all model description files, simulation
data, classic datasets
Model Parameters
• Dimensions
– 35 km East-West
– 40 km North-South
– 15 km deep
• Gridded model on 10 m grid
– 84 GB per parameter
• Velocity Range
– 1490 km/s (water) to 4800 m/s (Cretaceous)
• Density Range 1.003 gm/cc to 2.904 gm/cc
Acquisition Parameters
(Phase 1 Seismic)
• Variable-density acoustic
• Frequency: <1 to >25 Hz
• Source-receiver separation: max 9.9 km
– Receivers in rectangular grid around source
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Shot locations: 150 m grid over entire model
Shot, receiver depths: 15 m
Receiver spacing: 30 m
Sample interval 8 ms
Trace length: 16 s
Calculation grid: 30 km (for aperture)
60K+ shots, 450K traces/shot
3.5 GB data volume per shot (> 200 TB total)
SEAM Source Wavelet
Source wavelet
Source and receiver depths are 15 meters.
Npoles=8 f3db=26 Npoles=2 f3db=20
Npoles=6 f3db=24 Npoles=1 f3db=5
Npoles=4 f3db=22
Two ghosts
30 Hz high cut
Broad band
Flat spectrum after surface ghosts
Causal
Source: C. Stork, Tierra Geophysical
Source: C. Stork, Tierra Geophysical
Status of Simulations, Phase I
Variable-Density Acoustic
Number of Shots
40
North
30
20
10
Velocity at 4 km depth
0
40
North
30
20
10
Velocity at 4 km depth
0
40
North
30
20
10
Velocity at 4 km depth
0
40
Dark Blue: in Storage
Purple: QC Complete
Dark Red: Simulated
North
30
20
10
0
40
7599 Shots delivered
to participants
(about 3 TB compressed)
Blue: 2793-shot Classic Dataset
Red: 9-line Classic Datasets
– 15 and 17 m receiver depths
– free and absorbing upper surface
North
30
20
10
0
Next 6 Talks about SEAM
Development and Results
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Model Design and Construction
Numerical Simulation Issues
Acquisition Design and Classic Datasets
Data Storage & Distribution including
compression
• CSEM modeling
• Gravity modeling
Discussion of Phase II Project
• Begins at 4:00
• Two major options presented
– 4D
– Land
• Your input and preference are solicited