Abstract：
The main factors affecting seismic exploration is the propagation velocity of seismic waves in the medium. In the past, during marine seismic data processing, the propagation velocity of sea water was generally taken as a constant 1500 m/s. However, for deep water exploration, the sound velocity varies with the season, time, location, water depth, ocean currents, and etc.. It also results in a layered velocity distribution, so there is a difference of seismic traveltime, ray paths, and amplitude, which affect the migration imaging results if sea water propagation velocity is still taken as constant for the propagation wavefi eld. In this paper, we will start from an empirical equation of seismic wave velocity in seawater with changes of temperature, salinity, and depth, consider the variation of their values, build a seawater velocity model, and quantitatively analyze the impact of seawater velocity variation on seismic traveltime, ray paths, and amplitude in the seawater velocity model.
HAN Fu-Xing,SUN Jian-Guo,WANG Kun. The infl uence of sea water velocity variation on seismic traveltimes, ray paths, and amplitude[J]. APPLIED GEOPHYSICS, 2012, 9(3): 319-325.
[1]
Bertrand, A., and MacBeth, C., 2003, Seawater velocity variations and real-time reservoir monitoring: The Leading Edge, 22(4), 351 - 355.
[2]
Feng, S. Z., Li, F. Q., Li, S. Q., et al., 1999, Marine Science Introduction: Higher Education Press, Beijing.
[3]
Han, F. X., 2009, On some computational problems in wavefront construction method: PhD Thesis, College for Geoexploration Science Technology of Jilin University, Changchun.
[4]
He, J. X., Xia, B., Shi, X. B., et al., 2006, Prospect and progress for oil and gas in deep water of the world, and the potential and prospect foreground for oil and gas: Natural Gas Geoscience, 17(6), 747 - 753.
[5]
Huang, X. H., and Song, H., B., 2011, Ocean temperature and salinity distributions inverted from combined reflection seismic and XBT data: Chinese J. Geophys. (in Chinese), 54(5), 1293 - 1300.
[6]
Jones, E. J. W., 1999, Marine geophysics: University College London, London, 67 - 68.
[7]
Jones, S. M., Sutton, C., Hardy, R. J. J., and Hardy, D., 2010, Seismic imaging of variable water layer sound velocity in Rockall Trough, NE Atlantic, and implications for seismic surveying in deep water: Petroleum Geology Conference Series, 7, 549 - 558.
[8]
Liu, B. S., and Lei, J. Y., 1993, Water acoustic principles: Harbin Engineering University Press, Harbin, 59 - 64.
[9]
Song, Y., Song, H. B., Chen, L., Dong C. Z., and Huang X. H., 2010, Sea water thermohaline structure inversion from seismic data: Chinese J. Geophys. (in Chinese), 53(11), 2696 - 2702.
[10]
Vinje, V., Iversen, E., Åstebøl, K., and Gjøystdal, H., 1996a, Estimation of multivalued arrivals in 3D models using wavefront construction: Part I: Geophysical Prospecting, 44, 819 - 842.
[11]
Vinje, V., Iversen, E., Åstebøl, K., and Gjøystdal, H., 1996b, Estimation of multivalued arrivals in 3D models using wavefront construction: Part II: Tracing and interpolation: Geophysical Prospecting, 44, 843 - 858.
2012, Vol. 9 
