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More details about Rayfract® software

WET Wavepath Eikonal Traveltime tomography ( Fresnel volume approach) models multiple signal propagation paths contributing to one first break. Conventional ray tracing tomography is limited to the modelling of just one ray per first break. Also, our Eikonal solver (Lecomte, Gjoystdal et al. Geophysical Prospecting May 2000) used for traveltime field computation explicitly models diffraction besides refraction and transmission of acoustic waves. As a consequence the velocity anomaly imaging capability is enhanced with our WET tomographic inversion compared to conventional ray tomography.

Rayfract® supports any surface based 2D recording geometry, including roll-along seismic reflection lines. Up to 500 shots may be imported into the same 2D profile database. These shots may be recorded with just one or with multiple overlapping receiver spreads. 10 or more shots per receiver spread are recommended. The spacing of adjacent receivers may vary along the same user-defined receiver spread type. We support from 12 up to 360 channels per receiver spread. 24 or more channels are recommended.

The software handles extreme topography and allows computation of velocity vs. two-way time for reflection processing, i.e., for static corrections. Golden Software Surfer is required for automatic imaging and plotting of Delta-t-V and WET tomography output. You may download a free demo from http://www.goldensoftware.com. This is print-disabled, and edited tomogram plots can't be saved. But otherwise this works fine, for on-the-fly automatic creation of tomogram plots with our software, from computed Surfer .GRD velocity grid files. The demo has no time limit.

Shots positioned at the bottom of deep holes located on the 2D seismic profile, i.e., "uphole" shots, may be recorded with the same receiver spread layouts as surface-based shots. First breaks picked for these uphole shots will then be used to constrain the WET tomography solution. You may convert walkaway VSP surveys into uphole refraction surveys with our software and then use the resulting simulated uphole shots to constrain surface-based WET tomography.

Please note that our software supports the interpretation of both P-wave and S-wave seismic refraction surveys. Also, our software supports the conventional refraction seismic Plus-Minus method (as described by J.G. Hagedoorn 1959), as well as the Wavefront method as described by E. Brueckl 1987 and Glyn M. Jones and D.B. Jovanovich 1985. Our Wavefront method is an optimized version of the GRM Generalized Reciprocal Method, as described by Derecke Palmer 1980 and 1981.

For further details, please check our online help chapters "System limitations", "Seismic and header data import" etc. You are welcome to send us a test profile for free interpretation.


Copyright © 1996-2012 Intelligent Resources Inc. All rights reserved. RAYFRACT® is a registered trademark of Intelligent Resources Inc. in Canada and Switzerland.