泥页岩三维定量荧光分析技术与应用

泥页岩含油性评价是陆相页岩油勘探开发的基础。利用三维定量荧光分析,可以对泥页岩样品的含油性进行快速评价。而由于轻烃散失及泥页岩低孔渗特性的影响,以往针对常规油气建立的三维定量荧光分析方法,并不能直接应用于泥页岩样品分析。通过溶剂萃取时间、粒径大小及超声辅助等因素的对比条件实验,确定了泥页岩三维定量荧光分析技术的前处理方法及分析流程,并在江汉盆地页岩油专探井取心段进行了初步应用。结果表明,该井潜江组三段四亚段(潜34)10韵律及潜四段下亚段(潜34)6韵律和15韵律整体含油较高,是有利的页岩油目的层段。对比岩石热解结果,两种方法反映了一致的含油性变化趋势,说明三维定量荧光分析是一种快速、可信的含油性评价方法。

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.