Geological Controls on Oil Sands Reservoir and Bitumen Heterogeneity in Athabasca Oil Sands

Milovan Fustic, Geology and Geophysics, University of Calgary, Alberta, CANADA, [email protected]

Biodegraded oils dominate the world petroleum inventory, with the largest oil reserves being heavy oils and tar sands on the flanks of foreland basins in the Americas. The Athabasca Oil Sands of north-eastern Alberta is among the largest of them; however, despite much reservoir characterization the heterogeneity of bitumen is poorly known. A better understanding of the nature of bitumen and its spatial distribution is essential for future exploration, improvements in existing operations and for further academic and research studies. A detailed investigation of the variations in bitumen saturation and its composition in various depositional facies and investigation of suspected on-going anaerobic methanogenesis along the bitumen–water interface will be conducted.  Heterogeneity analysis on both regional and reservoir scales are expected to determine a relationship between depositional facies and petroleum composition including acids and geocatalysts. The first step will be to use geophysical logs, core and outcrop data from the McMurray Formation to build a geological framework and to create a sample database. The second step is to do lab analysis of bitumen extracts and solid residues. Upon the solid phase extraction, bitumen will be analysed for basic oil composition by Iatroscan, and then gas chromatography, and gas chromatography-mass spectrometry will be applied for advanced characterization including biomarkers identification. Finally, integrating lab data with petrophysical and geological data and analysis of 3D spatial distribution of bitumen, will facilitate the development of a predictive tool for bitumen heterogeneity as function of reservoir heterogeneity will conclude investigation.