All Issue

2019 Vol.29, Issue 2 Preview Page

Research Article

Seismic Weathering Correction Using IRS Approach: A Test to the Synthetic Data of Cheongju Granitic Bodies

IRS(간섭 굴절보정)를 이용한 탄성파 풍화대 보정: 청주 화강암체에 대한 적용

Yu-Gyeong Kang1
,
Jin-Hyeon Sa2
,
Ji-Soo Kim3*
,
Jong-Woo Kim4
강 유경1
,
사 진현2
,
김 지수3*
,
김 종우4
1Department of Earth and Environmental Sciences, Chungbuk National University, MsC. Student
2Department of Earth and Environmental Sciences, Chungbuk National University, MsC
3Department of Earth and Environmental Sciences, Chungbuk National University, Professor
4Department of Civil Engineering, Cheongju University, Professor
1충북대학교 지구환경과학과, 석사과정
2충북대학교 지구환경과학과, 석사
3충북대학교 지구환경과학과, 교수
4청주대학교 토목공학과, 교수
* Corresponding Author
30 June 2019. pp. 153-162
PDF XML Citation
Abstract

Rapid variations in the geometry (i.e., thickness) of the refractor and low velocities affect greatly the imaging of the reflectors of land seismic data. Conventional solutions to obtain the weathering models utilizes first break picking method, which requires time consuming steps and causes the human error in picking the first arrivals. A new interferometric approach (interferometric refraction statics, IRS) which utilizes the first arrival signal (S/N enhanced by refraction convolution stack) instead of first break picking, is tested in this study to the synthetic data from the velocity structure provided by surface geophysics (refraction, MASW) and borehole geophysics (tomography, SPS logging) for the Cheongju granitic bodies. The results of IRS approach are found to be better than the ones from conventional first break picking in terms of continuities and horizontal resolution of the reflectors. The unresolved long-wavelength statics in brute stack are much removed by IRS weathering correction and the overlying refractors (the base of shallow weathering zone) are incidentally delineated in the refraction convolution stack.

Keywords
land seismic data
weathering correction
interferometric refraction statics (IRS)
refraction convolution stack (RCS)

풍화대의 기하학적인 변화(두께 등)와 낮은 속도는 육상 탄성파 자료의 반사면 이미징에 큰 영향을 끼친다. 풍화대 모델을 얻기 위한 일반적인 방법은 초동 시간을 이용하는데, 이것은 수작업으로 진행되어 정확한 초동 발췌가 어렵고 그 과정에서 많은 시간이 요구되는 문제점들이 있어왔다. 초동시간 대신 굴절 곱말기 겹쌓기로 신호대잡음비가 향상된 초동신호를 이용하는 새로운 기법인 간섭 굴절보정(IRS)이 본 연구에서 시도되었다. 이 기법의 적용성 검토를 위해 지표탐사(굴절법, 여러채널 표면파 탐사)와 시추공탐사(토모그래피, SPS 검층) 자료에서 해석된 속도 구조를 토대로 만든 모델 자료를 이용하였다. 곱말기 겹쌓기로 향상된 초동신호를 이용하는 IRS 기법은 초동시간 발췌에 비해 겹쌓기 단면에 나타나는 장파장 성분을 대부분 제거하여 반사면의 연속성 및 수평 분해능을 향상시켰고 굴절곱말기 겹쌓기 연산과정에서 그 상부의 굴절면(천부 풍화대의 기저면)이 그려지는 효과가 있었다.

키워드
육상 탄성파자료
풍화대 보정
간섭 굴절보정
굴절곱말기 겹쌓기
References
1
Ait-Messaoud, M., Boulegroun, M.-Z., Gribi, A., Kasmi, R., Touami, M., Anderson, B., Van Baaren, P., El-Emam, A., Rached, G., Laake, A., Pickering, S., Moldoveanu, N., Özbek, A., 2005, New dimensions in land seismic technology, Oilfield Review, 17(3), 42-53.
2
Berryman, J.G., 1989, Fermat's principle and nonlinear traveltime tomography, Physical Review Letters, 62(25), 2953-2956.
10.1103/PhysRevLett.62.295310040136
3
Burger, H.R., 1992, Exploration geophysics of the shallow subsurface, Prentice-Hall, New York, 489 p.
4
Chun, J.H., Jacewitz, C.A., 1981, The weathering statics problem and first arrival time surfaces: 51st Annual International Meeting, Society of Exploration Geophysicists, Los Angeles.
5
Cox, M.J.G., 1999, Static corrections for seismic reflection surveys, Society of Exploration Geophysicists, 531 p.
10.1190/1.9781560801818
6
Dahl-Jensen, T., 1989, Reflection seismic studies in the baltic shield: special processing techniques and results, Uppsala University.
7
De Franco, R., 2005, Multi-refractor imaging with stacked refraction convolution section, Geophysical Prospecting, 53(3), 335-348.
10.1111/j.1365-2478.2005.00478.x
8
Khatchatrian, V., Galbraith, M., 2013, Interferometric approach to complete refraction statics solution, Geoconvention 2013:Intergration.
9
Kim, J.S., Han, S.H., Seo, Y.S., Lee, Y.J., 2005, Ground characterization of the Cheongju granite area using the geophysical methods, The Journal of Engineering Geology, 15(1), 41-55 (in Korean with English abstract).
10
Kim, J.S., Moon, W.M., Lodha, G., Serzu, M., Soonawala, N., 1994, Imaging of reflection seismic energy for mapping shallow fracture zones in crystalline rocks, Geophysics, 59(5), 753-765.
10.1190/1.1443633
11
Lee, S.A., 2018, First arrival picking of SH wave using 3-component geophone, Chungbuk National University (in Korean with English abstract).
12
Lee, S.J., Lee, C.H., Jang, H.S., Kim, J.S., 2011, Physical properties of and joint distribution within the Cheongju granitic mass, as Assessed from Drill-core and Geophysical Well-Logging Data, 21(1), 15-24 (in Korean with English abstract).
10.9720/kseg.2011.21.1.015
13
Marsden, D., 1993, Static corrections-a review, Part II, Geophys: The Leading Edge, 12(2), 115-120.
10.1190/1.1436936
14
Na, K.C., 1986, Nature and Geology of Chungbuk Province, Chungbuk Provincial Offices of Education, 271 p.
15
OYO Corporation, 2003, Refraction Processing Software, SeisImager/2D, Japan.
16
Palmer, D., 1980, The generalized reciprocal method of seismic refraction interpretation, Tulsa, Society of Exploration Geophysicists, 113 p.
10.1190/1.9781560802426
17
Palmer, D., 2001, Imaging refractors with the convolution section, Geophysics, 66(5), 1582-1589.
10.1190/1.1487103
18
Park Seismic LLC, 2014, Surface waves processing software, ParkSEIS, USA.
19
Schlumberger Ltd., 2014a, Seismic survey design & modeling, OMNI 3D, USA.
20
Schlumberger Ltd., 2014b, 2D/3D full PRO seismic processing software, VISTA, USA.
21
Woodward, M.J., 1992, Wave-equation tomography, Geophysics, 57(1), 15-26.
10.1190/1.1443179
22
Yilmaz, Ö., 2001, Seismic data analysis, Society of Exploration Geophysicists, 2065 p.
10.1190/1.9781560801580
Information
  • Publisher :Korean Society of Engineering Geology
  • Publisher(Ko) :대한지질공학회
  • Journal Title :The Journal of Engineering Geology
  • Journal Title(Ko) :지질공학
  • Volume : 29
  • No :2
  • Pages :153-162
  • Received Date : 2019-06-14
  • Accepted Date : 2019-06-20
  • DOI :https://doi.org/10.9720/kseg.2019.2.153
Journal Informaiton The Journal of Engineering Geology The Journal of Engineering Geology
Online Submission
  • NRF
  • KOFST
  • KISTI Current Status
  • KISTI Cited-by
  • crosscheck
  • orcid
  • open access
  • ccl
Journal Informaiton Journal Informaiton - close