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Estimation of subsurface-fracture orientation with the three-component crack-wave measurement; Kiretsuha sanjiku keisoku ni yoru chika kiretsumen no hoko suitei

Abstract

This paper reports experiments carried out to estimate subsurface-fracture orientation with the three-component crack-wave measurement. The experiments were performed by using existing subsurface cracks and two wells in the experimental field. An air gun as a sound source was installed directly above a subsurface crack intersection in one of the wells, and a three-component elastic wave detector was fixed in the vicinity of a subsurface crack intersection in the other well. Crack waves from the sound source were measured in a frequency bandwidth from 150 to 300 Hz. A coherence matrix was constituted relative to triaxial components of vibration in the crack waves; a coherent vector was sought that corresponds to a maximum coherent value of the matrix; and the direction of the longer axis in an ellipse (the direction being perpendicular to the crack face) was approximated in particle motions of the crack waves by using the vector. The normal line direction of the crack face estimated by using the above method was found to agree nearly well with the direction of the minimum crust compression stress measured in the normal line direction of the crack face existed in core samples collected from the wells, and measured at nearly  More>>
Authors:
Nagano, K; Sato, K; [1]  Niitsuma, H [2] 
  1. Muroran Institute of Technology, Hokkaido (Japan)
  2. Tohoku University, Sendai (Japan)
Publication Date:
May 01, 1996
Product Type:
Conference
Report Number:
CONF-9605233-
Reference Number:
SCA: 440700; 580000; 440400; PA: NEDO-96:913521; EDB-96:172478; SN: 96001687128
Resource Relation:
Conference: 94. SEGJ (The Society of Exploration Geophysicists of Japan) Conference, Butsuri tansa gakkai dai 94 kai (1996 nendo shunki) gakujutsu koenkai, Tokyo (Japan), 15-17 May 1996; Other Information: PBD: May 1996; Related Information: Is Part Of Proceedings of the 94th SEGJ (The Society of Exploration Geophysicists of Japan) Conference; PB: 475 p.; Butsuri tansa gakkai dai 94 kai (1996 nendo shunki) gakujutsu koenkai koen ronbunshu
Subject:
44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; 58 GEOSCIENCES; GEOLOGIC FRACTURES; AZIMUTH; PROBABILISTIC ESTIMATION; SEISMIC WAVES; SEISMIC DETECTORS; EPICENTERS; SEISMIC SOURCES; GUNS; ACOUSTICS; FREQUENCY DEPENDENCE; EIGENVECTORS; ELLIPTICAL CONFIGURATION; DRILL CORES; GEOBAROMETRY
OSTI ID:
395560
Research Organizations:
Society of Exploration Geophysicists of Japan, Tokyo (Japan)
Country of Origin:
Japan
Language:
Japanese
Other Identifying Numbers:
Other: ON: DE97709027; TRN: 96:913521
Availability:
Available from The Society of Exploration Geophysicists of Japan, 2-18, Nakamagome 2-chome, Ota-ku, Tokyo, Japan; OSTI as DE97709027
Submitting Site:
NEDO
Size:
pp. 420-422
Announcement Date:
Dec 02, 1996

Citation Formats

Nagano, K, Sato, K, and Niitsuma, H. Estimation of subsurface-fracture orientation with the three-component crack-wave measurement; Kiretsuha sanjiku keisoku ni yoru chika kiretsumen no hoko suitei. Japan: N. p., 1996. Web.
Nagano, K, Sato, K, & Niitsuma, H. Estimation of subsurface-fracture orientation with the three-component crack-wave measurement; Kiretsuha sanjiku keisoku ni yoru chika kiretsumen no hoko suitei. Japan.
Nagano, K, Sato, K, and Niitsuma, H. 1996. "Estimation of subsurface-fracture orientation with the three-component crack-wave measurement; Kiretsuha sanjiku keisoku ni yoru chika kiretsumen no hoko suitei." Japan.
@misc{etde_395560,
title = {Estimation of subsurface-fracture orientation with the three-component crack-wave measurement; Kiretsuha sanjiku keisoku ni yoru chika kiretsumen no hoko suitei}
author = {Nagano, K, Sato, K, and Niitsuma, H}
abstractNote = {This paper reports experiments carried out to estimate subsurface-fracture orientation with the three-component crack-wave measurement. The experiments were performed by using existing subsurface cracks and two wells in the experimental field. An air gun as a sound source was installed directly above a subsurface crack intersection in one of the wells, and a three-component elastic wave detector was fixed in the vicinity of a subsurface crack intersection in the other well. Crack waves from the sound source were measured in a frequency bandwidth from 150 to 300 Hz. A coherence matrix was constituted relative to triaxial components of vibration in the crack waves; a coherent vector was sought that corresponds to a maximum coherent value of the matrix; and the direction of the longer axis in an ellipse (the direction being perpendicular to the crack face) was approximated in particle motions of the crack waves by using the vector. The normal line direction of the crack face estimated by using the above method was found to agree nearly well with the direction of the minimum crust compression stress measured in the normal line direction of the crack face existed in core samples collected from the wells, and measured at nearly the same position as the subsurface crack. 5 refs., 4 figs.}
place = {Japan}
year = {1996}
month = {May}
}