| 摘要: |
| 古近系沙河街组是阳信洼陷最重要的生烃层段．其湖盆充填具阶段性和沉积演化的旋回性，形成了由沙四段、沙三段与沙一段组成的复合生烃系统和不同的地球化学特征．利用Rock-Eval生油岩评价仪、色谱一质谱仪等实验分析技术对不同层系样品进行了地球化学特征分析研究，其中生烃潜力指标包括有机碳含量(TOC)、残余生烃潜量(S1+S2)、氢指数IH、氯仿沥青“A”；成熟度指标包括热解峰温Tmax、奇偶优势参数OEP、饱和烃轻重比(C21+C22)/(C28+C29)及∑C21-/∑C22+、镜质体反射率Ro、莫烷/藿烷及甾烷生物标志物参数C29ββ(ββ+αα)、C29ααα20S(20S+20R)；古环境指标包括异构烷烃参数Pr/Ph、Pr/n-C17、Ph/n-C18及伽马蜡烷等．结果表明，沙四段为弱还原-还原性的半深湖沉积，沉积了一套中等厚度、分布局限的烃源岩(TOC平均为1．5%)，其较深位置的烃源岩基本进入成熟阶段，多形成成熟油；沙三段属弱还原-还原性的半深湖-深湖环境，其烃源岩中有机质丰度较高(TOC平均为3．5%)，大部分烃源岩处于未成熟-低成熟状态，主要形成未熟油；沙一段为湖水咸化、还原性的半深湖相环境，其烃源岩中有机质丰度高(TOC平均为5%左右)，但处于未成熟阶段，主要生成生物气． |
| 关键词: 阳信洼陷 烃源岩 生油岩 生烃系统 地球化学 |
| DOI：10.18307/2007.0212 |
| 分类号: |
| 基金项目:国家“十五”重点科技攻关项目(2001BA605A-09-21)资助 |
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| Multiplex hydrocarbon-generation system in Yangxin Sub-depression and its exploration potential |
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CHEN Zhonghong, ZHA Ming
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China University of Petroleum, Dongying, 257061, P.R.China
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| Abstract: |
| The shahejie Formation of Paleogene System is the most important hydrocarbon generation interval in Yangxin Sub-depression. Multiplex-set hydroearbon generation series of strata being of different geologieal-geoehemieal eharaeteristies were formed beeause of the staging property of the filling and evolution of Paleogene lake basin and the eyelieity of sedimentary proeess. The organie earbon eontent, the parameters of pyrolysis and biomarker eharaeters of saturated hydroearbon was investigated by using the means of Roek-Eval, GC-MS. The Sha-4 hydrocarbon souree roeks formed under the semi-saline to saline water environment, the eontent of organie matter (TOC) was 1.5% averagely, and most of them was being matured and formed into matured oil;The Sha-3 hydroearbon souree roeks formed under the deep-lake environment with fresh-slight saline water, the content of organic matter (TOC) was 3.5% averagely, and most of them was still immature and formed into immature oil;The Sha-1 immature hydroearbon souree roeks formed under the salt lake-saline water environment, the eontent of organie matter(TOC) was 5.0% averagely, they are formed into biogas. |
| Key words: Yangxin Sub-depression souree roek hydroearbon generation system geoehemistry |
