캐나다 앨버타 상부 데본기 Grosmont층의 불연속면 구조 특성

Characteristics of Fracture System of the Upper Devonian Grosmont Formation, Alberta, Canada

  • 엄정기 (부경대학교 에너지자원공학과) ;
  • 김민성 (부경대학교 에너지자원공학과) ;
  • 조석주 (고려대학교 지구환경과학과)
  • Um, Jeong-Gi (Dept. of Energy Resources Engineering, Pukyong National University) ;
  • Kim, Min-Sung (Dept. of Energy Resources Engineering, Pukyong National University) ;
  • Choh, Suk-Joo (Dept. of Earth and Environmental Sciences, Korea University)
  • 발행 : 2010.09.09

초록

The Upper Devonian Grossmont Formation in Alberta, Canada reserves an estimated 50 billion cubic meters of bitumen and possess about 1/6 of the total bitumen resources in northern Alberta. However, unlike the overlying Athabasca oil sands, non conventional bitumen resources has not been developed as yet. The carbonate rocks of Grosmont Formation have been subject to various stages of diagenesis, including dolomatization and karstification with a strong effect on the distribution of porosity and permeability, which resulted in highly heterogeneous reservoirs. An extensive fracture logging and mapping was performed on total of six boreholes located in the study area to explore the characteristics of fracture geometry system and the subsurface structures of carbonates reservoir that holds bitumen. Fractal dimension was used as a measure of the statistical homogeneity of the fractured rock masses. The applicability of random Cantor dust, Dc, as a fractal parameter was examined systematically. The statistical homogeneity of fractured carbonates rock masses was investigated in the study area. The structural domains of the rock masses were delineated depthwise according to estimated Dc. The major fracture orientation was dominated by horizontal beddings having dip of $0-20^{\circ}$. Also, fractures having high dip angles existed with relatively low frequency. Three dimensional fracture network modeling for each structural domain has been performed based on fracture orientation and intensity, and some representative conceptual models for carbonates reservoir in the study area has been proposed. The developed subsurface conceptual models will be used to capture the geomechanical characteristics of the carbonates reservoir.

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