Oil Shale, Vol.27, No.2, 179-189, 2010
INDEXES IN EVALUATING THE GRADE OF BOGDA MOUNTAIN OIL SHALE IN CHINA
This paper aims at exploring new evaluation indicators of oil shale in order to evaluate and classify the industrial grade of oil shale and to provide the evaluation parameters for exploration and development of Bogda Mountain oil shale in China. We use organic petrology and organic geochemistry methods to make a systematic study on the relationship between petrological type, organic component content, hydrocarbon-generating potential, total organic carbon (TOC) and oil yield of the oil shale, basing on the results, the corresponding evaluation indexes are proposed. The results show that lithologic types and industrial grade of oil shales can be categorized as follows: videlicet, the content of organic component lower than 5%, between 5% and 15%, between 15% and 25%, and over 25% correspond to non-oil shale, low-quality, medium-quality, and high-quality oil shale. The total content of organic components, hydrocarbon-generating potential, TOC and oil yield correlate significantly with each other, so they can be easily used as indexes to evaluate the industrial grade of oil shale. For example, the coefficient R between organic carbon content of oil shale and oil content is 0.978, the oil yield 3.5% corresponds to the TOC 7.5%, the oil yield 5% corresponds to the TOC 9.5%, and 10% to the TOC 17.0%.