--> Applications of Portable XRF Analysis to the Amaranth, Lodgepole and Bakken Formations of South Western Manitoba

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Applications of Portable XRF Analysis to the Amaranth, Lodgepole and Bakken Formations of South Western Manitoba

Abstract

Portable x-ray fluorescence is a useful tool for detecting geochemical proxies that help show productive hydrocarbon intervals. Accurate stratigraphic correlations are augmented by chemostratigraphic techniques, utilizing common mineral forming elements and trace element ratios and abundances. Lab data obtained from five Lower Amaranth cores, one Lodgepole core and one Three Forks/Bakken core located within the North Eastern part of the Williston basin provides a wealth of analytical and stratigraphic information. Visual analysis alone of the three slabbed formations reveals minor color variations but fails to show the subtle geochemical components required for understanding the mineralogical controls of hydrocarbon traps in the carbonate rich Lower Amaranth and Lodgepole reservoirs. The core study also provides additional information about the controls over source rock hydrocarbon potential in the Three Forks and Bakken Formations. Major elements, such as Si, Ca and Al were analyzed for rapid rock categorization into specific lithologies at every ten centimeter interval. Minor elements such as Mg, Fe, S, K20 and TiO2 were used to further define lithologies and provide insight into the diagenetic and detrital processes. Further analysis of detrital input in carbonates was indicated by Zr abundance and Th/U ratios. The trace elements utilized in this study provided information into hydrocarbon saturation potentials of prospective units; such as Mo, Zn and U serving as proxies for organic content. U, Mo, Fe and S being utilized as proxies for anoxia. Other comparisons were made to determine silica type (terrestrial, biogenic or authigenic). Analysis of micro-fracture populations provided possible target zones suitable for fracing. Iron and sulphur ratios were used to rapidly distinguish sulphides from microscopic evaporites and ferric oxides. Permeability was analyzed using Al/Si ratios to determine if detrital clays were affecting the hydrocarbon saturation in prospective units.