准噶尔盆地东部芦草沟组介形类化石生油特征的扫描电镜研究  

Scanning electron microscope study on oil generation characteristics of ostracod fossils from the Lucaogou formation in eastern Junggar Basin

作　　者：刘金 王剑 张晓刚 罗正江 尚玲 王桂君 LIU Jin;WANG Jian;ZHANG Xiao-gang;LUO Zheng-jiang;SHANG Ling;WANG Gui-jun(Research Institute of Experiment and Detection,Xinjiang Oilfield Company Petrochina,Karamay Xinjiang 834000,China)

机构地区：[1]中国石油新疆油田分公司实验检测研究院,新疆克拉玛依834000

出　　处：《电子显微学报》2021年第6期679-686,共8页Journal of Chinese Electron Microscopy Society

基　　金：国家科技重大专项资助项目(No.2017ZX05001002);中国石油科技重大专项资助项目(No.2019E-2602)。

摘　　要：为深化准噶尔盆地东部芦草沟组生烃母质认识,利用场发射扫描电镜与X射线能谱表征技术对介形类富有机质泥岩进行表征分析。结果表明,芦草沟组介形类生物化石分为钙质壳体和几丁质壳体两类。钙质壳体化石由白云石外壳、似蜂巢状几丁质中间层及内层层状几丁质三部分组成,几丁质壳体化石仅由几丁质组成。扫描电镜下芦草沟组有机质孔在20 nm~5μm之间,发育于有机质碎屑之间,呈不规则状、狭缝状,有机质孔为几丁质碎屑缩聚形成的碎屑间孔隙及有机质碎屑边缘生烃形成的生烃孔隙的混合孔隙。介形类来源的有机质在低成熟-成熟热演化阶段形成有机质孔,并发生了大量生烃活动,介形类富有机质泥岩游离烃S_(1)均值1.20 mg·g^(-1),壳体内部及壳体上见有大量生成的黑色重质组分油。研究结果打破了准噶尔盆地东部芦草沟组生烃母质主要为菌藻类的单一认识,对芦草沟组生烃母质的全面认识具有重要意义。研究同时对国内其它盆地介形类化石生烃研究具有启示意义。In order to deepen the understanding of the parent materials for hydrocarbon generation of the Lucaogou formation in the eastern Junggar basin,the ostracod fossils organic-rich mudstones were analyzed by field emission scanning electron microscopy(SEM)and X-ray energy spectrum(EDS).The results show that the ostracod fossils of the Lucaogou formation can be divided into calcareous shells and chitin shells.The calcareous shells consist of the dolomite shell,the mesosphere layer of the honeycombed chitin,while the inner layer of lamellar chitin.the chitin shells consist only of chitin.Under the scanning electron microscope,the organic pores of the Lucaogou formation were between 20 nm to 5μm and developed among the organic clasts in an irregular and narrow slit shape.The organic pores were the mixed pores of Interclastic pores formed by the condensation of chitin clasts and the hydrocarbon-generating pores formed by hydrocarbon generation at the edge of organic clasts.The ostracods-derived organic matter formed organic pores during the low maturation to maturation thermal evolution stage with a lot of hydrocarbon generation occurred.Ostracods-rich mudstone had an average free hydrocarbon S_(1)of 1.20 mg·g^(-1),and there were a lot of black heavy component oil in the shell and on the shell.The results break the single understanding that the parent material of the Lucaogou formation is mainly bacteria and algae in the eastern Junggar basin,and have important significance for a comprehensive understanding of the parent material of the Lucaogou formation.The study also shed light on the study of hydrocarbon generation characteristics of the ostracod fossils in other basins in China.

关 键 词：介形类化石 生烃母质 扫描电镜 芦草沟组 准噶尔盆地 

分 类 号：TE122.3[石油与天然气工程—油气勘探] TE121.2