HR: 0800h
AN: NS31A-06    [Abstracts]
TI: Analysis of overburden effects in seismic amplitudes in a strcuturally complex scenario of the Gulf of Mexico by 3D ray-tracing
AU: * Melendez Martinez, J
EM: jaimem@imp.mx
AF: INSTITUTO MEXICANO DEL PETROLEO, Eje Central Lazaro Cardenas Norte, Col. San Bartolo Atepehuacan, GUSTAVO A. MADERO, DF 07730, Mexico
AU: Ramos Martinez, J
EM: j_ramos_mar@yahoo.com
AF: PETROLEUM GEO SERVICES, 16010 Barkers Point Ln # 575 , HOUSTON, TX 77079, United States
AU: Gonzalez Ibarra, A
EM: agibarra@imp.mx
AF: INSTITUTO MEXICANO DEL PETROLEO, Eje Central Lazaro Cardenas Norte, Col. San Bartolo Atepehuacan, GUSTAVO A. MADERO, DF 07730, Mexico
AU: Ramirez Ortega, C
EM: cortega@imp.mx
AF: INSTITUTO MEXICANO DEL PETROLEO, Eje Central Lazaro Cardenas Norte, Col. San Bartolo Atepehuacan, GUSTAVO A. MADERO, DF 07730, Mexico
AU: Calderon Macias, C
EM: cxcalder@hotmail.com
AF: GX TECHNOLOGY, 2101 CityWest Blvd. Building III, HOUSTON, TX 77042, United States
AB: We perform illumination with 3D ray tracing for understanding possible effects of strong heterogeneity in seismic amplitude anomalies observed in the Gulf of Mexico. Credible velocity models in depth are build from integration of velocities obrtained from seismic data and lithological and well information. Real acquisition layouts are used as input in order to simulate illumination maps that can be compared to amplitude maps from actual data at selected target horizons. Geometric and reflection attributres are computyed using the wavefront reconstruction method, a shooting method that advances wavefronts in a smooth background velocity field within boundaries defined by target horizons. The observed lateral variability of ray density for some target horizons of 3D model suggests that morphology of the main geological structures corresponding to the overburden, might have a significant effect on amplitude attributes derived from processed seismic data. Typically, overburden effects are partially addressed in standard seismic processing flows. As a result, it is expected that amplitude anomalies observed in seismic sections that might lead to detection of fluids are hampered by geometric effects predicted by illumination analysis. We discuss situations in which performing this type of studies may lead to a more accurate discrimination of the reflectivity produced by lithological contrasts and/or presence of fluids from other wave propagation effects. An important requirement of illumination studies is the need of a depth-velocity model that is accurate for predicting zones with poor illumination. So we discuss the cost/benefit ratio for carrying out illumination analysis in some specific scenarios.
DE: 0540 Image processing
DE: 0545 Modeling (4255)
DE: 0902 Computational methods: seismic
DE: 0910 Data processing
DE: 0935 Seismic methods (3025, 7294)
SC: Near-Surface Geophysics [NS]
MN: 2007 Joint Assembly