湖相优质烃源岩模拟生烃过程中甾萜类化合物的特征  

Geochemical Characteristics of Steranes and Tepanes in Lacustrine Quality Source Rocks by Thermal Simulation Experiment

作　　者：梁明亮[1,2,3] 王作栋[2] 郑建京[2] 

机构地区：[1]中国地质科学院地质力学研究所,页岩油气评价重点实验室,北京100081 [2]中国科学院油气资源研究重点实验室,兰州730000 [3]中国科学院大学,北京100049

出　　处：《矿物岩石地球化学通报》2015年第5期968-973,共6页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金项目(41072106)

摘　　要：为了研究湖相优质烃源岩热演化生排烃过程中的生物标志化合物演化特征,选择低演化湖相烃源岩进行热模拟实验并对模拟实验产物开展对比研究。对烃源岩热模拟实验的液态排出物和残留样品抽提物的饱和烃馏分进行了气相色谱-质谱联用仪测试,并对检测出的丰富甾萜类系列化合物进行了分析。研究表明,当温度大于350℃之后,C27甾烷相对含量具有明显的增加趋势,并在450℃达到最大值;C2920S/(S+R)和C29ββ/(αα+ββ)值在350℃后持续升高,显示了与样品热成熟度之间良好的相关性。G/C30H值随着温度的增加有一个升高过程,可能与干酪根束缚部分伽马蜡烷的释放有关,但G/C30H值基本大于0.2以上,显示了较好的稳定性,是成熟烃源岩半咸水-咸水环境的良好指标。In order to understand the characteristics of biomarkers,steranes and tepanes,in lacustrine quality source rocks during hydrocarbon generation at high temperature,hydrous pyrolysis experiments were conducted at a temperature range of 250-550 ℃ on immature petroleum source rocks. Saturated hydrocarbons of bitumen and expelled oil obtained from experiments were analyzed using gas chromatography-mass spectrometry（ GC-MS）,and steranes and tepanes were detected at 217 m / z and 191 m / z,respectively. The distribution and variation of these compounds indicated that： the relative content of C27αα20R increased with temperature when over 350℃ and peaked at about 450℃; C2920 S /（ S ＋R） and C29ββ /（ αα＋ββ） increased with temperature,and C29/ C30 H also increased with temperature; the stable Gammacerane to C30 hopane ratio（ G / C30H） indicated that the Gammacerane index could be a good indicator for the salinity of water-column stratification.

关 键 词：甾烷 藿烷 热模拟 烃源岩 GC-MS 

分 类 号：P618.13[天文地球—矿床学]