Prestack time imaging algorithm with simultaneous velocity estimation in hard rock environments*
Konstantin Tertyshnikov 1 2 Andrej Bóna 1 Roman Pevzner 11 DETCRC, Department of Exploration Geophysics, Curtin University, Technology Park West Precinct, ARRC/CSIRO Building, H Block Level 4, 26 Dick Perry Ave, Perth, WA 6015, Australia.
2 Corresponding author. Email: k.tertyshnikov@postgrad.curtin.edu.au
Exploration Geophysics 45(3) 234-241 https://doi.org/10.1071/EG12080
Submitted: 7 December 2012 Accepted: 23 August 2013 Published: 24 September 2013
Abstract
Reflection seismic imaging faces several difficulties in hard rock environments. One of them is the estimation of the propagation velocity of seismic waves. Therefore, imaging algorithms that do not require prior construction of a velocity model seem promising for such environments. In this paper we illustrate an application of prestack time migration, which does not require an input velocity model, to hard rock conditions, and we demonstrate its effectiveness on synthetic data. This approach is based on an estimation of local event slopes (horizontal slownesses) in common-shot and common-receiver gathers and a subsequent calculation of the migration attributes (migration velocity, vertical traveltime and horizontal coordinates of the migrated reflection point). These attributes allow us to derive all the information needed to construct a time-migrated image. We also use the obtained migration velocities as an input velocity model for Kirchhoff prestack time migration (PSTM) and compare the results of the proposed approach with a conventional Kirchhoff migration using as an input the picked NMO velocity model. This application to a hard rock synthetic model illustrates the potential of the presented migration algorithm for imaging in hard rock seismic exploration. We believe that this approach can be used in hard rock seismic processing workflows as an automatic tool to obtain an input velocity model for the Kirchhoff PSTM.
Key words: hard rock, imaging, migration, prestack, seismic.
References
Bona, A, 2011, Shot-gather time migration of planar reflectors without velocity model: Geophysics, 76, S93–S101| Shot-gather time migration of planar reflectors without velocity model:Crossref | GoogleScholarGoogle Scholar |
Brown, S., Groves, D., and Newton, P., 2002, Geological setting and mineralization model for the Cleo gold deposit, Eastern Goldfields Province, Western Australia: Mineralium Deposita, 37, 704–721
| Geological setting and mineralization model for the Cleo gold deposit, Eastern Goldfields Province, Western Australia:Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xntlynurk%3D&md5=c760d11817aed122fa5ac80776dd9167CAS |
Claerbout, J. F., 1992, Earth soundings analysis: processing versus inversion: Blackwell Scientific Publications, 6.
Cooke, D., Bona, A., and Hansen, B., 2009, Simultaneous time imaging, velocity estimation, and multiple suppression using local event slopes: Geophysics, 74, WCA65–WCA73
| Simultaneous time imaging, velocity estimation, and multiple suppression using local event slopes:Crossref | GoogleScholarGoogle Scholar |
Fomel, S., 2002, Applications of plane-wave destruction filters: Geophysics, 67, 1946–1960
| Applications of plane-wave destruction filters:Crossref | GoogleScholarGoogle Scholar |
Fomel, S., 2007, Velocity-independent time-domain seismic imaging using local event slopes: Geophysics, 72, S139–S147
| Velocity-independent time-domain seismic imaging using local event slopes:Crossref | GoogleScholarGoogle Scholar |
Harlan, W., and Claerbout, J., 1996, Tieman’s conversion of common-midpoint slant stacks to common-source: SEP-92, Stanford Exploration Project, 293–298.
Harlan, W., Claerbout, J., and Rocca, F., 1984, Signal/noise separation and velocity estimation: Geophysics, 49, 1869–1880
| Signal/noise separation and velocity estimation:Crossref | GoogleScholarGoogle Scholar |
Neidell, N. S., and Taner, M. T., 1971, Semblance and other coherency measures for multichannel data: Geophysics, 36, 482–497
| Semblance and other coherency measures for multichannel data:Crossref | GoogleScholarGoogle Scholar |
Ottolini, R., 1983a, Signal/noise separation in dip space: SEP-37, Stanford Exploration Project, 143–149.
Ottolini, R., 1983b, Velocity independent seismic imaging: SEP-37, Stanford Exploration Project, 59–68.
Riabinkin, L. A., 1957, Fundamentals of resolving power of controlled directional reception (CDR) of seismic waves, in L. Lu, ed., Slant-stack processing: SEG, P36–P60.
Rieber, F., 1936, A new reflections system with controlled directional sensitivity: Geophysics, 1, 97–106
| A new reflections system with controlled directional sensitivity:Crossref | GoogleScholarGoogle Scholar |
Schleicher, J., Costa, J. C., Santos, L. T., Novais, A., and Tygel, M., 2009, On the estimation of local slopes: Geophysics, 74, P25–P33
| On the estimation of local slopes:Crossref | GoogleScholarGoogle Scholar |
Sword, C. H., Jr, 1987, Tomographic determination of interval velocities from reflection seismic data: the method of controlled directional reception: Ph.D. thesis, Stanford University.
Telford, W. M., Geldart, L. P., and Sheriff, R. E., 1990, Applied geophysics: Cambridge University Press.
Urosevic, M., and Evans, B., 2007, Feasibility of seismic methods for imaging gold deposits in Western Australia: Minerals and Energy Research Institute of Western Australia.
Yilmaz, Ö., 2001, Seismic data analysis: Society of Exploration Geophysicists.