2006 RESEARCH UTAM ACCOMPLISHMENTS AND 2007 GOALS

  1. 3D Reverse Time Migration
    • RESULT: 3D and 2D tests of wavefront migration (WMM) and bottom-up target-oriented migration (BUM). Both methods promise to be substantially faster than standard reverse time migration (RTM).
    • IMPLICATION: Codes appear to be accurately imaging data from 2D models and simple 3D models.
    • PROBLEMS: None.
    • 2007 GOALS: Rigorous tests on performance of RTM, WMM, and BUM.

  2. Seismic Interferometry
    • RESULT: First draft of book "Seismic Interferometry" given to sponsors. Includes MATLAB exercises. Classification matrix coherently organizes different research directions.
      • Tested surface wave interferometry on 3D field data and results for eliminating surface waves are encouraging.
      • Tested interferometric interpolation on 2D and 3D data. Results are good for 2D data, but only fair for 3D data.
      • SSP transform data migrated using VSP shot gathers as Green's functions. Visibly enhances image beneath the salt.
      • Preliminary attempt at imaging reflectors beneath salt by elastic PS wave imaging, including transmitted PS waves. Ambiguous results.
      • Contourlet transformed used to filter surface waves.
    • IMPLICATIONS: Surface wave filtering by interferometry looks promising. Interferometry book organizes research directions around 9x9 classification matrix.
    • PROBLEMS: 3D interpolation results not too accurate, but shows some promise. It needs the extra step of a matched filter.
    • 2007 GOALS: Rigorous comparison between standard 3D surface wave filtering and interferometric surface wave filtering. Incorporate matching filter with interferometric interpolation. Continue contourlet transform research. Try the SSP->VSP-SWP transform on field data? Advance efforts to image subsalt reflectors with PS imaging.

  3. Multiple Migration
    • RESULT: Salt flank imaging using Kirchhoff migration with a double-bounce imaging condition.
    • IMPLICATION: Compared to RTM, inexpensive way to illuminate some salt flanks that are underlain by a base reflector. Transforms (surface seismic profile) SSP data into VSP data.
    • PROBLEMS: Need accurate knowledge of base reflector geometry.
    • 2007 GOALS: Multiple migration of 3D data.

  4. Tomography
    • RESULT: Test of multigrid tomography shows smoother images than dynamic smoothing tomography. Quick application of early arrival waveform tomography shows slight improvement over tomostatics from traveltime tomography.
    • IMPLICATION: Perhaps multigrid tomography is moderately better than dynamic smoothing tomography.
    • PROBLEMS: Two sequential internships for Chaiwoot prevented much effort on the EWT.
    • 2006 GOALS: Full EWT tests on new Saudi data. Possibly elastic inversion.

  5. Hybrid Computing Shootout
    • RESULT: Tested CELL, FPGA, and Multi Core computers for wave equation modeling. Results show that the FPGA machine runs about 50% faster than an AMD multi-core (i.e., dual duo) computer, but is an order-of-magnitude more difficult to program. The CELL (i.e. \$600. Playstation 3) is about 70% the speed of an AMD dual duo, and is moderately more difficult to program than the multi-core computer.
    • IMPLICATION: Stay with the multi-core machines. FPGAs might even gain a 4x speedup with special programming, but code development is quite costly.
    • PROBLEMS: PS3 sold out in most stores. Bought one at last minute.
    • 2007 GOALS: Stay with the multi-core machines.

  6. Migration Deconvolution
    • RESULT: Implemented poststack MD on new data set from PEMEX. Only option was poststack MD because source-receiver coordinates not available. Fast version of MD was shown and some parts of image show improvement compared to a decimated full MD result.
    • IMPLICATION: Fast MD method used for optimal MD filter parameters.
    • PROBLEMS: Need prestack data and source-receiver coordinates.
    • 2007 GOALS: Improve MD performance; apply to SaudiAramco data.

  7. Goal Summary
    • We hope to explore bottom-up and wavefront versions of RTM as a practical 3D imaging tool. Elastic wave imaging beneath salt is a goal with Xiang's 2D simulations and PS migrations. Using natural data to assist with SSP extrapolation is useful and will be a major topic of research. There will be a major effort devoted to early arrival wavefrom tomography with multiscale elements: Chaiwoot will devote full time to this endeavor and Sam Brown will likely be involved using some suggestions from Veritas. There will be interaction with our reverse time migration researchers. Prism wave migration will be explored and its extension to interferometry and tomography will be elaborated. Natural datuming methods will be employed for VSP data and using it to allow SSP data to see below the overburden and salt. Interpolation and surface wave filtering methods will be employed using contourlets and interferometry. 3D Visualization of seismic data will be explored in conjunction with the Computer Science department.