基于小角X射线散射页岩油储层介孔特征研究

发布时间：2018-05-04 16:41

本文选题：页岩油 + 小角X射线散射　；参考：《高校地质学报》2017年04期

【摘要】：采用不同极性有机溶剂对取自东营凹陷地区泥页岩样品进行了逐次抽提处理,使用小角X射线散射表征技术对处理前后样品进行介孔分布特征表征和分析。结果显示,正己烷溶剂抽提效果较弱,极性较强的氯仿、甲醇/丙酮/氯仿混合溶剂及二氯甲烷/甲醇混合溶剂能够萃取出孔隙中赋存的有机质,二硫化碳/N-甲基吡咯烷酮混合溶剂由于极性太强对孔隙进行改造和破坏。经溶剂抽提后样品主峰位置分布在10 nm左右,最可几孔径值和中值孔径尺度分别介于6.7~14.5 nm和15.9~22.9 nm之间,细介孔体积百分比分布在9.5%~32.3%范围内。在泥页岩生烃阶段,粘土矿物为油气储存提供了有效储集空间,高粘土矿物相对含量的泥页岩对应的介孔分布曲线向更小孔径处集中,细介孔体积百分比与分形维数参数之间均存在明显的正相关关系,可见与粘土矿物有关的孔隙比表面趋向于粗糙化,比表面积趋大,为油气的赋存提供有利的条件。自然演化样品及热模拟样品介孔分布表征揭示了泥页岩从低成熟向高成熟热演化阶段转化的过程中,细介孔体积占介孔总体积百分比呈现出先增大后减小的趋势,而粗介孔与之相反。
[Abstract]:The shale samples from Dongying depression were extracted with different polarity organic solvents. The mesoporous distribution characteristics of the samples before and after treatment were characterized and analyzed by means of small angle X-ray scattering technique. The results showed that chloroform with strong polarity, methanol / acetone / chloroform and dichloromethane / methanol could extract organic matter from pores. The mixed solvent of carbon disulfide / N-methyl pyrrolidone modified and destroyed the pores because of its strong polarity. After solvent extraction, the main peak distribution is about 10 nm, the maximum pore size and median pore size are between 6.7N 14.5 nm and 15.9N 22.9 nm, and the percentage of mesoporous volume is in the range of 9.55% and 32.3%, respectively. In the hydrocarbon generation stage of shale, clay minerals provide an effective reservoir space for oil and gas storage, and the mesoporous distribution curve of shale with high relative content of clay minerals is concentrated at a smaller pore size. There is an obvious positive correlation between the volume percentage of fine mesoporous and fractal dimension parameters. It can be seen that the pore specific surface area of clay minerals tends to be roughened and the specific surface area tends to be larger, which provides favorable conditions for the occurrence of oil and gas. The mesoporous distribution of natural evolution samples and thermal simulated samples revealed that the percentage of mesoporous volume to total mesoporous volume increased first and then decreased during the transformation of shale from low maturation to high maturation. The coarse mesopore is the opposite.
【作者单位】：南京大学地球科学与工程学院;
【基金】：国家重点基础研究发展计划(973)项目(2014CB239102) 国家自然科学基金资助项目(41172139;41372127)联合资助
【分类号】：P618.13

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