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Using Simulation to Address Challenges of Subsalt Imaging in Tertiary Basins with Emphasis on Deepwater Gulf of Mexico (Paper 23566). Michael Fehler SEG Advanced Modeling Project. SEG Advanced Modeling Project (SEAM). Use numerical simulation to
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Using Simulation to Address Challenges of Subsalt Imaging in Tertiary Basins with Emphasis on Deepwater Gulf of Mexico(Paper 23566) Michael Fehler SEG Advanced Modeling Project
SEG Advanced Modeling Project (SEAM) • Use numerical simulation to • Reduce exploration and development risk through improvements to geophysical methods • Relevant and challenging datasets for testing • Acquisition design • New imaging methods • Joint inversion methodologies • Advance state-of-the-art of numerical simulation
How? • Earth Model representative of GOM DW • 35km x 40km x 15km • Cell size 20m x 20m x 10m • Computer generated datasets • Outputs look like real field data • State-of-the-art simulation codes • Over-sampled for acquisition testing
Perspective View of SEAM Model Figure courtesy C. Stork, Landmark Software and Services
Scope of Work • Subsalt acoustic earth model and simulation • Extend earth model for shear velocity, anisotropic resistivity • Non-seismic simulations: • Gravity • Electromagnetic and Magnetotelluric • Acoustic anisotropic TTI simulation • Elastic simulation
SEAM Model Geological Indicator Volume 10 9 17 8 14 15 7 13 6 12 11 5 4 3 2 1
Elastic parameter modeling from Rock properties Seismic modeling from Elastic parameters Rock Properties Vshale, Porosity, Fluids, Sat, Pressure, Resis, … Elastic Parms Vp, Vs, Dn, Cij, Q (and their reflectivities) Seismic Waves P, S, qP,S, atten/disp; EM response, Gravity Elasticity inversion for rock/reservoir properties AVO reflectivity inversion for elastic parameters Interest group on this end: Reservoir characterization and Monitoring Interest groups on this end: Imagers, Tomographers, Processors Rooting the Seismic Simulation to the Rock Properties Engages Several Interest Groups Joe Stefani, Chevron
Model Properties are Derived from Log and Petrophysical Data
Reservoirs in SEAM Phase I Model Catalogue Pleistocene 5 small turbidite fans Pliocene 2 E-W trending braided channel systems Upper Miocene 2 N-S trending braided channels in eastern half Middle Miocene 2 Large turbidite fans that enter from North Lower Miocene 2 Large turbidite fans that enter from North Vertically integrated Reservoir thickness (white indicates thicker reservoir)
Turbidite and Stream Channel Reservoirs Defined Using Geostatistics
Several Geophysical Parameters Defined Using Consistent Approach
Model Testing to Design Acquisition Tim Brice, WesternGeco
Ensure the Quality of Numerical Simulations Through the Use of Benchmark Codes Comparison of Production and Benchmark Simulations
SEAM PHASE I GRAVITY MODEL Gravity at sea level calculated using GM-SYS 3D gxy gxz gxx gyz gyy gz gzz
CSEM Simulation Data Shows Sensitivity to Reservoirs on East Side of Salt
TTI Acquisition Plan • ~36,000 shots • Vertical Seismic Profiles on 4 wells • Quality control • Classic dataset extraction • Acoustic anisotropic model; tilted axis of symmetry • ~36,000 shots • ~440,000 surface receivers per shot • Vertical Seismic Profiles in 4 wells
Proposed Elastic Acquisition Plan • ~12,000 shots • ~460,000 surface receivers per shot • Seafloor 4-component receivers • Vertical Seismic Profiles in 4 wells
SEAM Model Used for Studies of Wave Phenomena Finite Difference Simulation Boundary Integral Simulation
Conclusions • SEAM Phase I is providing geophysical data of unprecedented scale • Model is robust and easily extended for uses beyond current modeling effort • Honor geology, rock, and reservoir properties • Numerical datasets available for use in studying acquisition, imaging, joint imaging for exploration and reservoir assessment • Joint geophysical imaging approaches
Acknowledgments • Research Partnership to Secure Energy for America for support (RPSEA Subcontract No. 07121-2001) • SEAM participating companies (www.seg.org/seam) • Participating company representatives to the SEAM Management Committee • SEAM Board of Directors