GETT3D: 

3-D Traveltime Computation
Traveltime slice through the SEG/EAGE Salt model.

Very Fast Algorithm
3DGeo's 3-D traveltime module (GETT3D) provides an extremely fast and accurate tool for computing Green's functions in complicated geological structures. GETT3D is based on a proprietary finite-difference algorithm (patent pending) for solving the high-frequency approximation to the wave equation. The algorithm computes the traveltimes on a 3-D cartesian grid, is unconditionally stable and correct to the order of accuracy of the finite-difference solution.

A fast computational engine is used for solving and advancing the first arrival wave-propagation front. The engine combines elements of finite-difference eikonal solver and wavefront construction to obtain better accuracy, speed and stability than each method taken separately.

Geophysical Aspects Efficient and stable 3-D traveltime computation is
necessary for a large number of data processing modules: 3-D Kirchhoff
prestack and poststack migration, 3-D Kirchhoff datuming, velocity estimation, focusing analysis, and inversion. GETT3D is particularly well suited for computing the Green's functions for 3-D prestack Kirchhoff migration because the speed and robustness of the algorithm ensure an accurate and stable traveltime solution.

A Stable Solution for Complicated Structures 3-D prestack Kirchhoff depth migration relies heavily on 3-D traveltime computation especially in areas of complex geological structure where 3-D prestack imaging is needed. In such areas the complex velocity model creates stability and accuracy problems for many 3-D finite-difference traveltime algorithms. In such areas 3-D traveltimes using adaptive, velocity dependent grid increments are less efficient than 3DGeo's solution. GETT3D uses a fixed cartesian grid to globally solve the eikonal equation with no loss in accuracy. Turning waves are also accurately handled. 3DGeo is currently developing a multiple arrival 3-D traveltime module to be integrated as an option into GETT3D.

Easy Integration The 3-D traveltime package is modular in design and can be customized and integrated for a client's specific environment. GETT3D is available on Unix workstations, parallel-vector supercomputers and other architectures. If desired, 3DGeo can integrate the package into a client's processing environment or add it as a Promax, Focus or Views module.