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http://dx.doi.org/10.9720/kseg.2013.4.457

Identification of Subsurface Discontinuities via Analyses of Borehole Synthetic Seismograms  

Kim, Ji-Soo (Dept. of Earth and Environmental Sciences, Chungbuk National University)
Lee, Jae-Young (Dept. of Earth and Environmental Sciences, Chungbuk National University)
Seo, Yong-Seok (Dept. of Earth and Environmental Sciences, Chungbuk National University)
Ju, Hyeon-Tae (Dept. of Earth and Environmental Sciences, Chungbuk National University)
Publication Information
The Journal of Engineering Geology / v.23, no.4, 2013 , pp. 457-465 More about this Journal
Abstract
We integrated and correlated datasets from surface and subsurface geophysics, drilling cores, and engineering geology to identify geological interfaces and characterize the joints and fracture zones within the rock mass. The regional geometry of a geologically weak zone was investigated via a fence projection of electrical resistivity data and a borehole image-processing system. Subsurface discontinuities and intensive fracture zones within the rock mass are delineated by cross-hole seismic tomography and analyses of dip directions in rose diagrams. The dynamic elastic modulus is studied in terms of the P-wave velocity and Poisson's ratio. Subsurface discontinuities, which are conventionally identified using the N value and from core samples, can now be identified from anomalous reflection coefficients (i.e., acoustic impedance contrast) calculated using a pair of well logs, comprising seismic velocity from suspension-PS logging and density from logging. Intensive fracture zones identified in the synthetic seismogram are matched to core loss zones in the drilling core data and to a high concentration of joints in the borehole imaging system. The upper boundaries of fracture zones are correlated to strongly negative amplitude in the synthetic trace, which is constructed by convolution of the optimal Ricker wavelet with a reflection coefficient. The standard deviations of dynamic elastic moduli are higher for fracture zones than for acompact rock mass, due to the wide range of velocities resulting from the large numbers of joints and fractures within the zone.
Keywords
fracture zones; acoustic impedance; synthetic seismogram; well logging; dynamic elastic modulus;
Citations & Related Records
Times Cited By KSCI : 3  (Citation Analysis)
연도 인용수 순위
1 Eissa, E. A. and Kazi, A., 1988, Relation between static and dynamic Young's moduli of rocks, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr, 25(6), 479-482.   DOI   ScienceOn
2 Hwang, S., Park. I., Yoon, K., Kim, C., Bae, D., and Ko, Y., 2003, Investigation of and Application to Rock Mass, Borehole Test, Korean Society of Engineering Geology, 1.6-1-1.6-30.
3 Kang, D., Jong, T., and Lee, J., 2000, Static and Dynamic Elastic Properties of the Iksan Jurassic Granite, Korea, Jour. of the Korean Geophysical Society, 3(2), 99-112.   과학기술학회마을
4 Kim, J., Ree, J., Han, S., Kim, H., Lee, Y., Lee, K., and Joo, B., 2003, The Ilkwang Fault in Southeastern Korea Revealed by Geophysical and Trench Surveys. Journal of the Geological Society of Korea. 39(2), 211-223.   과학기술학회마을
5 KIGAM, 2008, DIPROWIN, Korea.
6 Mashinskii, E. I., 2004, Variants of the Strain-Amplitude Dependence of Elastic Wave Velocities in Rocks under Pressure, Journal of Geophysics and Engineering, 1(4), 295-306.   DOI   ScienceOn
7 Nano Tech., 2011, Technical Report for Haeundae Project.
8 Ree, J., Lee, Y., Rhodes, E., Park, Y., Kwon, S., Chae, U., Jeon, S., and Lee, B., 2003, Quaternary Reactivation of Tertiary Faults in the Southeastern Korean Peninsula, The Island Arc, 12, 1-12.   DOI   ScienceOn
9 Reynolds, J. M., 2011, An Introduction to Applied and Environmental Geophysics Second Edition, Blackwell, 688p.
10 Ryu, K. and Chang, C., 2006, Comparison of Rock Young's Moduli Determined from Various Measurement Methods, Journal of Engineering Geology, 16(1), 1-14.
11 Schlumberger, 2012a, OMNI3D Workshop Seismic Survey Design & Modeling, USA.
12 Song, M., Kim, H., and Park, J., 2002, Relationship between Lithology and Rock Physical Property using Borehole Prospecting, Journal of Engineering Geology, 1(2), 127-135.
13 CGGVeritas, 2007, Hampson-Russell Software-8 R1.2, France.
14 Chang, H. S., Lim, H. R., and Hong, J. H., 1999, Borehole Seismics: Review and Its Application to Civil Engineering, Conference of Korean Society of Earth and Exploration Geophysicists, 176-201.
15 Yilmaz, o., 2001, Seismic Data Analysis, Society of Exploration Geophysics, 2027p.
16 Yu, Y., Song, M., and Lee, K., 2007, Data Analysis of Suspension P-S Velocity Logging in Banded Gneiss Area around Hanam, Gyeonggi Province, Journal of Engineering Geology, 17(4), 623-631.   과학기술학회마을
17 Schlumberger, 2012b, VISTA 2D/3D Full PRO Seismic Processing Software, USA.
18 Kim, J., Song, Y., Yoon, W., Cho, I., and Kim, H., 2009, Applied Geophysics, Sigma Press, 792p.
19 Park, C., Park, J., and Song, M., 2002, Relationship between Dynamic Elastic Modulus and Lithology using Borehole Prospecting, Jour, Korean Erath Science Society, 23(6), 507-513.   과학기술학회마을