摘要
为研究生-排烃过程对页岩纳米孔隙演化的影响,选择低成熟且生烃潜力差异显著的茂名油页岩和大隆组硅质页岩为研究对象,经低温热模拟和索氏抽提增加了页岩在生油高峰期的排烃效率后,通过高温热模拟实验,使具有不同残留烃含量的样品演化到过成熟阶段。通过热模拟产物的地球化学分析和孔隙测量,获得了不同残留烃含量的页岩有机质与孔隙发育的热演化规律。结果表明,在高成熟阶段,富I型有机质的黏土质茂名油页岩的残留烃大量转化为固体沥青,促进了中孔、大孔的发育,对微孔的发育影响较小;具Ⅱ型有机质的大隆组硅质页岩,高成熟阶段残留于页岩中的极性有机组分与干酪根生成新的固体有机质,其纳米孔隙发育较差,导致残留烃对中孔和大孔的发育影响不明显。
To study the influence of hydrocarbon expulsion and retention on the evolution of nanometer-scale pores in shales,two immature shales(Maoming oil shale and Dalong siliceous shale)with different kerogen types were heated at low temperatures to the oil-window,and hydrocarbon expulsion efficiency was enhanced by Soxhlet extraction.Then,samples with different contents of residual hydrocarbon were isothermally pyrolyzed to over mature stages.After investigating geochemical characteristics and porosities of the heated samples,distinct pore structure develo?pments were found in samples with different contents of residual hydrocarbon.Our results suggest that for the shale with typeⅠkerogen and abundant clay minerals at high maturities,residual hydrocarbons are converted to solid bitumen and this facilitates the development of mesopores and marcopores;however,micropore evolution is only slightly influenced.For the shale with typeⅡkerogen and siliceous minerals,residual hydrocarbons and kerogen coevolve to a new kind of organic solids which generates a small number of pores and their influence on pore evolution is slight.
作者
贺儒良
贾望鲁
彭平安
HE Ru-liang;JIA Wang-lu;PENG Ping-an(State Key Laboratory of Organic Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《地球化学》
CAS
CSCD
北大核心
2018年第5期575-585,共11页
Geochimica
基金
中国科学院战略性先导科技专项B类(XDB10010204)
中国科学院广州地球化学研究所"一三五"项目(135TP201602)
关键词
排-留烃
页岩
纳米孔隙
热模拟
hydrocarbon expulsion and retention
shale
nanometer-scale pores
pyrolysis
