煤系有机质生成烃类中甾烷系列化合物地球化学特征——以高温封闭体系下热模拟实验为例  

Geochemical Characteristics of Steranes of Coal Generated Hydrocarbons:A Case of High Temperature and Fined Simulated Experiment

作　　者：孙涛[1] 段毅[2] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国科学院油气资源研究重点实验室,甘肃兰州730000

出　　处：《天然气地球科学》2011年第6期1082-1087,共6页Natural Gas Geoscience

基　　金：国家自然科学基金"不同演化阶段煤层气成因及其判识的模拟实验研究"项目(编号:40872092);国家自然科学基金项目(编号:40772069);中央高校基本科研业务费专项项目(编号:2011PY0238)联合资助

摘　　要：选择泥炭和褐煤进行热模拟试验并开展对比研究,目的是全面获得煤系有机质生烃特征。通过对草本泥炭和褐煤的热模拟实验液态产物饱和烃进行色谱—质谱分析得到,在泥炭和褐煤热模拟样品中均检测出丰富的甾族系列化合物,且以C29甾烷占优势。研究发现,随热模拟温度增高,C29甾烷相对含量减少,温度在350℃之后趋于稳定;而C27甾烷和C28甾烷相对含量具有增加的趋势,暗示了C29甾烷的去甲基效应。C2920S/(20S+20R)值和C29ββ/(ββ+αα)值可以判识样品是否成熟或未熟,是良好的成熟度指标。∑重排甾烷/∑规则甾烷值可以区分成样品成熟度。研究发现,在低演化阶段,泥炭和褐煤模拟曲线存在显著差异,而在高演化阶段,二者吻合较好。所以,对比研究泥炭和褐煤的地球化学特征,对认识煤系有机质生烃特征具有重要意义。Peat and coal are selected to do simulation experiment in order to understand characteristics of hydrocarbon generation from coal.According to GC-MS analysis for soluble organic matters extracted from simulated products of peat and coal in closed system pyrolysis,the abundance of steranes in the saturated hydrocarbon fractions with the maximum intensities of C29-regular steranes is observed,reflecting that the terrestrial higher plants are main parent materials.The relative content of C29-regular steranes decreases with simulated temperature increase,and become little variation,suggesting that the thermal maturity should be considered when the relative content of regular steranes is used to identify source material.C29 sterane-20S/（20S＋20R） and C29 sterane-C29ββ/（ββ＋αα） is a selected parameter for identifying the mature or immature organic matter.∑diasteranes/∑regular-sterane is also a maturity parameter.The experimental results show that the simulation curve of peat and coal is different at low mature stage,and become similar at high mature stage.So,it is meaningful to understand the hydrocarbon generation from peat to coal by contrast simulated experiment.

关 键 词：甾烷 泥炭 煤岩 成熟度 

分 类 号：TE122.113[石油与天然气工程—油气勘探]