TTI Anisotropic Simulation

Transcription

TTI Anisotropic Simulation
DW-2001: Geophysical
Modeling for Studying
Acquisition and Processing
Methods in the Deepwater
Gulf of Mexico
UDW Forum
June 22 & 23, 2010
Secure Energy for America
Goals
• Reduce GOM exploration and development risk
• Relevant and challenging simulated datasets
 improve survey acquisition design
 imaging and processing research
 joint inversion studies
• Advance state-of-the art in numerical simulation
• Industry forum for subsalt geophysical issues
Scope of Work
• Build on success of SEAM Phase I “Subsalt”
• Extend earth model for Vs and resistivity
• Acoustic Absorbing Upper Surface (AUS) simulation
• Non-seismic simulations:
 Gravity
 Electromagnetic and Magnetotelluric
• Elastic simulation
• Anisotropic TTI simulation
Salt Model
60 GOM Blocks
15 km deep
Model Overview
Structural Features
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–
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complex salt body with rugose top, root, overhangs
9 horizons that extend across the entire model
12 radial faults arrayed under salt near to salt root
1 overturned sediment raft proximate to salt root
2 internal sutures in salt and a heterogeneous salt cap
Stratigraphic Features
– 13 turbidite fan and braided channel reservoirs
– fine layering - 10m x 10m x 10m grid cells
– geophysical parameters derived from rock properties
Simulation rooted in Rock Properties
Elastic parameter modeling
from Rock properties
Rock Properties
Vshale, Porosity, Fluids,
Sat, Pressure, …
Geophysical modeling
from parameters
Geophysical Parameters
Vp, Vs, Dn, Cij, Q,
Resistivity
Elasticity inversion
for rock/reservoir properties
Interest group on this end:
Reservoir characterization
and Monitoring
Seismic Waves
P, S, qP,S, atten/disp;
EM response, Gravity
AVO reflectivity inversion
for elastic parameters
Interest groups on this end:
Imagers, Tomographers, Processors
Modified from Joe Stefani; Chevron
Vp Model Profile
Turbidite Reservoirs
Example of turbidite fans in Pleistocene, Middle Miocene and Lower
Miocene. Color indicates sand to shale ratio.
Braided Channel Reservoirs
~ 11 km long by ~3 km wide
Example of braided channels in Pliocene and Upper Miocene.
Statistical features of the channels (length, width, thickness,
sinuosity, Vshale) from real world measurements
~ 11 km long by ~3 km wide
From Joe Stefani; Chevron
Absorbing Upper Surface Simulation
• No free-surface multiples
• 9,000 acoustic shots: grid and 4km wide swath
• Up to 450,000 traces per shot
• Simulation complete – awaiting QC
• Applications:
• Direct evaluation of imaging algorithms
• Evaluation of de-multiple algorithms*
* when combined with Phase I acoustic free surface dataset
AUS Acquisition Plan
600 m grid – 2793 shots
4 km swath – 6209 shots
~ 11 km long by ~3 km wide
~ 11 km long by ~3 km wide
White = reservoir thickness
Free Surface and AUS Comparison
~ 11 km long by ~3 km wide
~ 11 km long by ~3 km wide
Quality Assurance with Benchmark Code
~ 11 km long by ~3 km wide
~ 11 km long by ~3 km wide
Non-Seismic Simulations
• Gravity (full tensor) complete
• Earth model extended for resistivity parameters
• Rv and Rh relative to bedding
• CSEM 3D simulation
• Lawrence Berkeley National Lab for benchmark
• acquisition parameters established
• vendor bid request in preparation
• Magnetotelluric simulation
Gravity
Simulation
Txx
Txy
Txz
Tyy
Tyz
Gz
Free-air anomalies at 150 m level
background density 2.2 g/cm3
15
From Neda Bundalo; Marathon
Tzz
EM Parameters Rh and Rv
~ 11 km long by ~3 km wide
~ 11 km long by ~3 km wide
CSEM Acquisition Plan
• 3D
acquisition
• 5 azimuth source lines
on each receiver side
~ 11 km long by ~3 km wide
• 10 km line offset
~ 11 km long by ~3 km wide
From Michael Frenkel; EMGS
Elastic Simulation
• Vs parameterization near complete
• Compute intensive
• Acquisition trade-offs under evaluation
• Sandia National Lab contracted for benchmarks
• Vendor capability under development
• SEAM project providing incentive
Vs derived from Log and Petrophysical Data
Vs Model
~ 11 km long by ~3 km wide
~ 11 km long by ~3 km wide
Vs to Vp Comparison
~ 11 km long by ~3 km wide
~ 11 km long by ~3 km wide
TTI Anisotropic Simulation
• TTI – Tilted Transverse Isotropy
• Immediate industry need
• Contract extension nearly finalized
• TTI parameterization of SEAM earth model
• Up to 10,000 TTI acoustic shots
• Delivery, August 2011
23 Industry Participants
~ 11 km long by ~3 km wide
~ 11 km long by ~3 km wide
DW-2001 Update
~ 11 km long by ~3 km wide
RPSEA UDW Forum
June 22, 2010
Peter Pangman
[email protected]
Office: 918-497-5518
~ 11 km long by ~3 km wide

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