A Study on Slowness Time Coherence Application and its Characteristics from Sonic Log Experiment in Model Holes

모형공에서의 음파실험을 통한 STC 기법의 적용과 특성 비교

  • Kim, Yeong-Hwa (Department of Geophysics, Kangwon National University) ;
  • Zhao, Weijun (Department of Geophysics, Kangwon National University)
  • 김영화 (강원대학교 지구물리학과) ;
  • Published : 2007.11.30

Abstract

Slowness time coherence (STC) technique has been applied to 3-receiver slim hole sonic log using 3 NX sized concrete model holes of different physical properties. We analyzed the effects of different source center frequencies on the wave forms, their amplitude spectra, and their STC results. We could determine the sonic velocity of each mode accurately by the application of STC method with the semblance projection and efficient selection of center frequency. Theoretical model and experimental model hole studies indicate that 4-receiver condition is the most ideal for STC in near surface slim hole sonic log. The result also indicates that favorable STC result can be obtained from three-receiver sonic log provided with the help of the first arrival picking method.

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