Transcript Slide 1
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 – – – – – 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