保靖地区龙马溪组高成熟海相页岩吸附气量及其影响因素

发布时间：2018-06-25 06:37

本文选题：保靖地区 + 海相页岩　；参考：《中国石油勘探》2017年04期

【摘要】：页岩吸附气量是含气性评价和资源潜力预测的关键参数,保靖地区志留系龙马溪组海相页岩热演化程度高,页岩吸附气量尚未查明,成为亟待研究的关键问题。采集研究区BY-1井龙马溪组页岩岩心样品12个,开展了页岩TOC、热成熟度(R_o)、X射线衍射、场发射扫描电镜、低压液氮吸附和高压甲烷等温吸附等分析测试。结果表明,研究区海相页岩有机质丰度高,TOC范围是0.57%~2.16%;热演化程度高,R_o的范围为2.86%~3.76%;矿物组分中石英含量为33.7%~73.9%,斜长石含量为0.7%~16.9%,黏土矿物含量为15.8%~54.4%;页岩中纳米级孔隙发育,以粒间孔和有机质孔为主;低压液氮吸附实验结果展示页岩孔径分布范围宽,以2~50nm的中孔为主;高压等温吸附实验揭示保靖地区龙马溪组页岩的吸附气量较高,为0.82~3.56m3/t,平均为1.93m3/t。保靖地区页岩吸附气量主要受到有机质丰度和中孔、微孔比表面积的控制,龙马溪组页岩有机质处于高成熟阶段,有机质热演化产生大量的微孔和中孔,二者比表面积较大,为页岩气吸附提供了较大的空间,页岩的吸附气量大。
[Abstract]:Shale adsorptive gas capacity is a key parameter for gas bearing evaluation and resource potential prediction. The thermal evolution of marine shale of Silurian Longmaxi formation in Baojing area is high and the amount of shale adsorbed gas has not been determined. Twelve samples of shale cores from Longmaxi formation in BY-1 well were collected and analyzed by means of TOC, thermal maturity (Ro) X ray diffraction, field emission scanning electron microscopy, low pressure liquid nitrogen adsorption and high pressure methane isotherm adsorption. The results show that the TOC range of marine shale organic matter abundance is 0.57 ~ 2.16; the range of high thermal evolution is 2.86 ~ 3.76; the quartz content of mineral component is 33.773.9%, the plagioclase content is 0.7 ~ 16.9, and the clay content is 15.88 ~ 54.4; the nanometer pore is developed in shale, and the content of plagioclase is 15.84.4. The results of low pressure liquid nitrogen adsorption experiments show that the pore size distribution of shale is wide, and that of 2~50nm is the main pore. The high pressure isothermal adsorption experiment shows that the gas adsorption capacity of Longmaxi formation shale in Baojing area is relatively high, which is 0.82m3.56m3 / t, with an average of 1.93m3t. The amount of gas adsorbed by shale in Baojing area is mainly controlled by the abundance of organic matter and the specific surface area of mesopore and micropore. The organic matter of Longmaxi formation is in the high mature stage, and the thermal evolution of organic matter produces a large number of micropores and mesoporous areas. It provides a large space for the adsorption of shale gas, and the amount of gas adsorbed by shale is large.
【作者单位】：神华地质勘查有限责任公司;中国石油大学(北京)非常规天然气研究院;
【基金】：国家自然科学基金项目“页岩非均质性和微—纳米孔喉结构对含气性的控制机理编号”(41472112)
【分类号】：P618.13

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