Geophysics and Geophysical Exploration (지구물리와물리탐사)

Korean Society of Earth and Exploration Geophysicists (한국지구물리·물리탐사학회)
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A Study of Waveform Inversion for Improvement of Sub-Salt Migration Image

암염돔 하부 구조의 구조보정 영상 개선을 위한 파형역산 기법 연구

  • Ha, Wan-Soo (Department of Energy Systems Engineering, Seoul National University) ;
  • Pyun, Suk-Joon (Research Institute of Energy and Resources, Seoul National University) ;
  • Son, Woo-Hyun (Department of Energy Systems Engineering, Seoul National University) ;
  • Shin, Chang-Soo (Department of Energy Systems Engineering, Seoul National University) ;
  • Ko, Seung-Won (Korea National Oil Company) ;
  • Seo, Young-Tak (Korea National Oil Company)
  • 하완수 (서울대학교 에너지시스템공학부) ;
  • 편석준 (서울대학교 에너지자원신기술연구소) ;
  • 손우현 (서울대학교 에너지시스템공학부) ;
  • 신창수 (서울대학교 에너지시스템공학부) ;
  • 고승원 (한국석유공사) ;
  • 서영탁 (한국석유공사)
  • Published : 2008.08.30
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Abstract

The sub-salt imaging technique becomes more crucial to detect the hydro-carbonates in petroleum exploration as the target reservoirs get deeper. However, the weak reflections from the sub-salt structures prevent us from obtaining high fidelity sub-salt image. As an effort to overcome this difficulty, we applied the waveform inversion by implementing multi-grid technique to the sub-salt imaging. Through the comparison between the conventional waveform inversion using fixed grid and the multi-grid technique, we confirmed that the waveform inversion using multi-grid technique has advantages over the conventional fixed grid waveform inversion. We showed that the multi-grid technique can complement he velocity estimation result of the waveform inversion for imaging the sub-salt structures, of which velocity model cannot be obtained correctly by the conventional fixed grid waveform inversion.

석유탐사 분야에서 탐사대상이 되는 저류층이 갈수록 심부화되고 복잡한 지층 구조로 옮겨감에 따라 암염층 하부 구조를 영상화하는 기술은 석유 및 가스층의 탐지를 위해 매우 중요하게 부각되고 있다. 그러나 암염돔 구조의 특성상 안염돔 하부로부터의 반사 에너지가 미약하기 때문에 하부구조의 정확한 영상을 얻기는 힘들다. 이러한 어려움을 극복하고자 본 연구에서는 암염돔 하부 구조 영상화를 위해 다중격자(multi-grid) 기법을 사용하여 파형역산을 수행하였다. 고정격자를 이용한 통상적인 주파수 영역 파형역산 기법으로 얻은 결과와의 비교를 통해 암염돔 구조 및 하부 구조의 영상화에서 다중격자를 적용한 파형역산 기법의 장점을 확인하였다. 본 연구 결과를 통해 고정격자를 이용한 파형역산 기법으로 정확한 영상을 얻기 어려웠던 암염돔 구조에서도 다중격자를 적용하여 향상된 영상을 얻을 수 있음을 보여 주었다.

Keywords

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