합성탄성파자료를 이용한 지진파 간섭법의 가상반사파 영상 특성 = Characteristics of Virtual Reflection Images in Seismic Interferometry Using Synthetic Seismic Data

다국어 초록 (Multilingual Abstract)

To characterize virtual reflection images of deep subsurface by the method of seismic interferometry, we analyzed effects of offset range, ambient noise, missing data, and statics on interferograms. For the analyses, seismic energy was simulated to be generated by a 5 Hz point source at the surface. Vertical components of particle velocity were computed at 201 sensor locations at 100 m depths of 1 km intervals by the finite difference method. Each pair of synthetic seismic traces was cross-correlated to generate stacked reflection section by the conventional processing method. Wide-angle reflection problems in reflection interferometry can be minimized by setting a maximum offset range.
Ambient noise, missing data, and statics turn to yield processing noise that spreads out from virtual sources due to stretch mutes during normal moveout corrections. The level of processing noise is most sensitive to amplitude and duration time of ambient noise in stacked sections but also affected by number of missing data and the amount of statics.

국문 초록 (Abstract)

지진파 간섭법으로 구한 심부 가상 반사파 영상 특성 분석을 위하여, 벌림 범위, 무작위 잡음, 손실 자료, 정적이상 등의 요인이 간섭파 단면에 미치는 영향을 분석하였다. 중심주파수 5 Hz의 지표 점샘에서 발생한 지진파 입자운동속도의 수직성분을 1 km 간격으로 100 m 깊이에 매설된 201개 수신기에서 유한차분법으로 계산하였다. 모든 합성지진파 트레이스의 쌍을 교차 상관하여 간섭파를 구하였고, 통상적인 반사파 처리방법으로 반사단면을 작성하였다. 분석결과, 반사파 간섭법의 광각반사에 따른 문제점들은 최대 벌림범위를 설정하여 최소화할 수 있었으며, 무작위 잡음, 손실 자료, 정적 이상 등은 수직 시간차 보정시 이완뮤트의 영향으로 가상 샘으로부터 퍼져나가는 형태의 처리잡음이 발생함이 밝혀졌다. 이들 처리잡음의 수준은 공통 중간점 겹쌓기 단면상에서 배경잡음의 크기 및 지속시간에 가장 민감하며, 손실된 자료의 수와 정적 이상의 증가에 따라서도 증가하는 특성을 보인다.

참고문헌 (Reference)

1 Bakulin, A., "Virtual source: New method for imaging and 4D below complex overburden" 2477-2480, 2004

2 Mehta, K., "Virtual source method applied to crosswell and horizontal well geometries" 29 (29): 712-723, 2010

3 Bakulin, A., "Virtual source appli- cations to imaging and reservoir monitoring" 26 (26): 732-740, 2007

4 Wapenaar, K., "Tutorial on seismic interferometry: Part 1 - Basin principles and applications" 75 (75): 75A195-75A209, 2010

5 Kennett, B. L. N., "Traveltimes of global earthquake location and phase identification" 105 (105): 429-465, 1991

6 de Hoop, A. T., "Time-domain reciprocity theorems for acoustic wave fields in fluids with relaxation" 84 (84): 1877-1882, 1988

7 Bharadwaj, P., "Theory of supervirtual refraction interferometry" 188 (188): 263-273, 2012

8 Schuster, G. T., "Theory of daylight/interferometric imaging: Tutorial: 63rd Conference and Technical Exhibition" A32-, 2001

9 Wapenaar, K., "Theory of acoustic daylight imaging revised" 2269-2272, 2002

10 Bakulin, A., "The virtual source method: Theory and case study" 71 (71): SI139-SI150, 2006

11 Mikesell, D., "The virtual refraction: Useful spurious energy in seismic interferometry" 74 (74): A13-A17, 2009

12 Claerbout, J., "Synthesis of a layered medium from its acoustic transmission response" 33 (33): 264-269, 1968

13 Kang, T.-S., "Surface-wave tomography from ambient seismic noise of accelerograph networks in southern Korea" 33 (33): L17303-, 2006

14 Fokkema, J. T., "Seismic applications of acoustic reciprocity" Elsevier Scientific Publ. Co., Inc. 1993

15 Schuster, G. T., "Seismic Interferometry" Cambridge University Press 2009

16 Yilmaz, O., "Seismic Data Analysis: Processing, Inversion, and Interpretation of Seismic Data" Society of Exploration Geophysicists 2001

17 Draganov, D., "Reflection images from ambient seismic noise" 74 (74): A63-A67, 2009

18 Dziewonski, A. M., "Preliminary reference Earth model" 25 (25): 297-356, 1981

19 Draganov, D., "Passive seismic imaging in the presence of white noise sources" 23 (23): 889-892, 2004

20 Cho, H.-M., "P- and S-wave velocity model along crustal scale refraction and wide-angle reflection profile in the southern Korean Peninsula" 582 (582): 84-100, 2013

21 Hooke, R., "Micrographia: or Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses. With Observations and Inquiries Thereupon" The Royal Society 1665

22 Campillo, M., "Long-range correlations in the diffuse seismic coda" 299 (299): 547-549, 2003

23 Snieder, R., "Extracting the Green's function from the correlation of coda waves: A derivation based on stationary phase" 69 (69): 046610-, 2004

24 Lin, F.-C., "Eikonal tomography: Surface wave tomography by phase front tracking across a regional broadband seismic array" 177 (177): 1091-1110, 2009

25 Kim, K. Y., "Crustal structure of the southern Korean peninsula from seismic waves generated by large explosions in 2002 and 2004" 164 (164): 97-113, 2007

26 Hurich, C., "Combined surface and borehole seismic imaging in a hard rock terrain: A field test of seismic interferometry" 78 (78): B103-B110, 2013

27 Ferrandis, J., "Application of virtual-source technology to the Zuidwending gas storage project" 28 (28): 296-301, 2009

28 Clayton, R., "Absorbing boundary conditions for acoustic and elastic wave equations" 67 (67): 1529-1540, 1977