Apr 4th-North Tech Brkfst: Automatic Early Arrival Traveltime Tomography and Its Applications*
Sponsored by Anadarko and Lumina Reservoir, Inc.
Meeting Location:
Anadarko Petroleum
1201 Lake Robbins Drive
The Woodlands, TX 77380
NOTE: You Must be Logged in To Register
Speaker: Jun Tang, WesternGeco, a division of Schlumberger
Recent advances in Seismic data acquisition have significantly improved our capability in imaging complex subsalt structures. These data also provide extremely valuable refractions energies, including diving wave, head wave and large angle reflections, for velocity inversion and anisotropy analysis. We have developed a method of macro velocity inversion that does not require explicit picking of either common image point gathers or first breaks. In this method seismic data are first decomposed into Gaussian packets. Packets associated with early-arrival energies are selected and used as input to a tomography solver. The outputs of the solver are velocity and Thomsen’s anisotropy parameters, or any of their combinations. Using information contained in the packets we can correctly model the early-arrival energies (first breaks and/or other refractions). The workflow is fully automatic and can be used in a batch processing environment with minimum human intervention. We have applied our method in two field dataset. The first field data example is for a shallow marine seismic data project. We are able to obtain a better shallow velocity model using our method than a legacy approach. In the second field data example we have applied our method on a deep water dataset from a dual coil acquisition, with full-azimuth and long-offset coverage. Our method can correctly model early-arrival energies recorded at long offsets and use them in the iterative inversion such that better estimation of velocities and anisotropy parameters in shallow sediments can be achieved. We have tested different starting models for the inversion. We are able to get very similar results, suggesting that our method is not sensitive to accuracy of a starting model.
Speaker Biography: Jun Tang, WesternGeco, a division of Schlumberger
Jun obtained his BSc degree in Physics from Peking University, China, in 2000 and his MSc degree in Electrical and Computer Engineering from Rice University in 2002. He started working as an Electrical Engineer at Freescale Semiconductor Inc. in 2002. He joined Nexus Geoscience Inc. in 2009 as a Research Geophysicist. Currently he is a Senior Geophysicist working for Schlumberger. His interests include various topics in seismic velocity model building and imaging.
Breakfast will be available starting at 7:00 AM
Technical Talk will start at 7:30
Event will end by 8:30
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