Computational methods for improving the resolution of subsurface seismic images

Technical Report · Tue May 01 04:00:00 EDT 1990

DOI:https://doi.org/10.2172/7004095· OSTI ID:7004095

Larner, K; Hale, D; Bleistein, N; Cohen, J

We have implemented two-dimensional (2-D) finite difference modeling of elastic waves for study of seismic waves that propagate rather parallel to bedding, as in cross-well seismic surveys and reflections from steep reflectors in surface-seismic surveys. Snapshots of the propagating waves generated and displayed during the course of computation on a high-speed, interactive workstation show tunneling of evanescent waves, a phenomenon not predictable from the ray theory that is the basis of current velocity-determination methods. Accurate solutions from this program will be our standard for analysis of the more efficient, approximate methods that we are developing. We have also developed an interactive algorithm that characterizes geologic structure as a Deluaney mesh, an optimum triangulation of a medium based on supplied node points. Current work is aimed at determining the data structure best suited for efficient ray tracing in 2-D and three-dimensional (3-D) models, for use in high-resolution imaging and interactive estimation of velocity in media in which velocity varies both laterally and vertically. We have developed two new methods for more accurate and more computationally efficient imaging of the subsurface. The first is a stable, accurate, and computationally efficient method for extrapolation 2-D seismic wavefields in depth. The second is an extension of this new depth extrapolation method to 3-D seismic surveys through a digital signal-processing device known as the McClellan transformation. 7 refs., 10 figs.

• Research Organization: Colorado School of Mines, Golden, CO (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: FG02-89ER14079
• OSTI ID: 7004095
• Report Number(s): DOE/ER/14079-1; ON: DE90011527
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ACCURACY
ALGORITHMS
BOREHOLES
CAVITIES
DOCUMENT TYPES
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
IMAGES
MATHEMATICAL LOGIC
PROGRESS REPORT
SEISMIC P WAVES
SEISMIC S WAVES
SEISMIC WAVES
SUBSURFACE ENVIRONMENTS
THREE-DIMENSIONAL CALCULATIONS
TRANSFORMATIONS
TWO-DIMENSIONAL CALCULATIONS
WAVE PROPAGATION