Computational methods for improving the resolution of subsurface seismic images
We have developed and refined an interactive algorithm that characterizes geologic structure as a constrained Delauney mesh, an optimum triangulation of a medium based on supplied node points along with constraints that certain edges of triangles (e.g., those associated with geologic interfaces) be fixed. The triangulation uses spatial data structures that contain an adjacency topology of the model that enables all triangles to be aware of and communicate with their neighbors. Ray tracing of seismic waves through the mesh of triangles is then particularly efficient because ray paths know which triangle they are entering when they leave a previous one, and, with the chosen characterization of velocity structure, ray paths are simply parabolas within each triangle. With this ray tracing, we have implemented the method of Gaussian beams for efficient, interactive generation of synthetic seismograms on an IBM RS/6000 advanced workstation. Current work is aimed at extending the method to three-dimensions, wherein the triangles become tetrahedra, and to make the model generation and modification fully interactive. We have also developed a new approach to doing migration for media in which velocity does not vary laterally. With care taken to minimize grid dispersion, this approach, which operates in the time-wavenumber-domain, is capable of accurately imaging reflections from interfaces at and beyond 90 degrees, such as happens for overhanging salt domes. A selection of other developments are summarized, as well. 15 refs., 4 figs.
- Research Organization:
- Colorado School of Mines, Golden, CO (USA)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- FG02-89ER14079
- OSTI ID:
- 5717422
- Report Number(s):
- DOE/ER/14079-6; ON: DE91012641
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dynamic ray tracing and its application in triangulated media
Computational methods for improving the resolution of subsurface seismic images. Progress report, September 15, 1991--September 14, 1993
Related Subjects
SEISMIC SURVEYS
CALCULATION METHODS
SUBSURFACE ENVIRONMENTS
GEOLOGIC MODELS
BOREHOLES
GEOLOGIC STRUCTURES
IMAGE PROCESSING
IMAGES
PROGRESS REPORT
SEISMIC WAVES
THREE-DIMENSIONAL CALCULATIONS
TOPOGRAPHY
TWO-DIMENSIONAL CALCULATIONS
WAVE PROPAGATION
CAVITIES
DOCUMENT TYPES
GEOPHYSICAL SURVEYS
PROCESSING
SURVEYS
580000* - Geosciences