Three-dimensional quantitative fluorescence analysis and application in shale

The evaluation of mudstone/shale oil-bearing capacity is the basis for the exploration and development of shale oil. Using three-dimensional quantitative fluorescence analysis, we can quickly evaluate the oil-bearing capacity of mudstone/shale samples. However, the three-dimensional quantitative fluorescence analysis method established for conventional oil and gas cannot be directly applied to mudstone/shale due to the loss of light hydrocarbons and the low porosity and permeability. The comparative experiments of factors such as solvent extraction time, particle size and ultrasound assistance determined the pre-treatment method and analysis process of the three-dimensional quantitative fluorescence analysis of mudstone/shale. A preliminary application was made in the cored section of a shale oil exploratory well in the Jianghan Basin. The 10th rhythm of the Eq₃⁴ submember and the 6th and 15th rhythms of the lower Eq₄ submember of the Qianjiang Formation show a strong oil-bearing capacity, which are regarded as favorable exploration targets. Compared with rock pyrolysis results, the two methods reflect a consistent change trend of oil-bearing capacity, indicating that the three-dimensional quantitative fluorescence analysis is a fast and reliable method.