马朗凹陷低熟页岩油地球化学特征及成烃机理  

Geochemical Characteristics and HydrocarbonGenerating Mechanism of Low-Mature Shale Oil in Malang Sag

作　　者：吴红烛[1] 黄志龙[1] 杨柏松[2] 柳波[1] 闫玉魁 桑廷义 文川江 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油天然气股份有限公司对外合作部,北京100007 [3]中国石油吐哈油田分公司勘探开发研究院,新疆哈密839009

出　　处：《吉林大学学报（地球科学版）》2014年第1期56-66,共11页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金青年科学基金项目(41202101)

摘　　要：勘探实践和研究表明，马朗凹陷二叠系芦草沟组源内油气为页岩油，该原油C29甾烷立体异构化参数 w（20S）/w（20S＋20R）、w（ββ）/w（αα＋ββ）均为0．2～0．4，为典型低熟原油。通过对芦草沟组烃源岩地球化学和有机岩石学特征的综合研究，发现低熟页岩油的生烃母质为原生的富氢无定形体，这些无定形体在沉积早期经历过细菌的改造作用，致使其具有特殊的生烃演化模式，即低熟成熟阶段早期（ Ro 为0．55％～0．75％）处于生油高峰，对应埋深为1800～2900 m ，埋深大于或小于该主峰带，烃源岩生烃能力急剧降低。泥岩生烃模拟实验、热解、抽提等实验数据表明：芦草沟组低熟页岩油正是位于该主生带的源岩所生，处于生烃带的源岩区即为马朗凹陷低熟页岩油富集的有利地区。Exploration practices and researches show that hydrocarbon in the source rocks of the Lucaogou Formation of the Permian ,Malang sag was shale oil and also a typical low-mature oil with both sterane isomerization parameters （20S/（20S ＋ 20R） and ββ/（αα ＋ ββ）） between 0 .2 and 0 .4 . Through comprehensive study of geochemical and organic petrology characteristics in the hydrocarbon source rock of Lucaogou Formation ,we find that the parent material of this low-mature shale oil was hydrogen-rich amorphous solid and experienced the bacteria transformation in the early sedimentary stage , w hich resulted in the formation of the particular hydrocarbon-generating evolution model . Namely ,during the low-mature and early mature stage with Ro values 0 .55% 0 .75% ,there is an oil＆amp;nbsp;generation peak w hose burial depth ranges from 1 800 to 2 900 m , and the hydrocarbon-generating potential of source rock drops sharply beyond the main hydrocarbon-generating zone . The results of hydrocarbon-generating simulation experiments , rock pyrolysis analysis and organic extraction of mudstone prove that the low-mature shale oil in Lucaogou Formation was generated by the hydrocarbon source rocks within the range of main hydrocarbon-generating zone ,where was the beneficial places of shale oil accumulation .

关 键 词：低熟油 页岩油 主生烃带 富氢无定形体 地球化学 

分 类 号：TE122.1[石油与天然气工程—油气勘探]