摘要
对羌塘盆地东部刻莫地区石炭系杂多群16个烃源岩样品的饱和烃和芳烃组分的GC-MS分析表明,其烃源岩正构烷烃主要是以C_(23)为主峰碳的单峰型,n C21-/n C22+值介于0.22~0.74之间,规则甾烷主要以C_(29)占优势,少数以C_(27)占优势,在C_(27)-C_(28)-C_(29)三角图中主要位于混合源区域,芳烃组分中检测出了与高等植物有关的海松烯和1-甲基菲。这些结果表明,杂多群烃源岩有机质生源以高等植物输入为主,低等水生生物有机质对成烃母质也有一定贡献。杂多群烃源岩Pr/Ph比值为0.83~1.43,一般大于1;1-甲基菲/9-甲基菲比值为0.77~9.95,1-甲基菲含量较高,同时还检测出源于高等植物的海松烯(1,7-二甲基菲);"三芴"系列化合物总体分布特征表现为OF>SF>F、SF>OF>F或者OF>F>SF,在ΣSF/(ΣF+ΣSF)-ΣOF/(ΣF+ΣOF)关系图上主要落于氧化-还原环境附近,可能为弱氧化-弱还原环境,也有部分样品位于沼泽相或煤的氧化环境中。杂多群烃源岩OEP值为1.01~1.16,C_(29)ααα20S/ααα(20S+20R)和C_(29)αββ/(ααα+αββ)比值分别为0.17~0.45和0.27~0.49,根据甲基菲和烷烃二苯并噻吩换算出的等效镜质体反射率平均值分别为0.70%和0.85%,反映出杂多群烃源岩具有成熟有机质的特征。
Based on gas chromatography mass spectrometry（ GC-MS） techniques,the authors in this paper give a detailed study of molecular fossils characteristics of the source rocks from the Carboniferous Zaduo Group in eastern Qiangtang Basin. The analytical results indicate that the n-alkanes in the Zaduo Group source rocks are composed of n C13-n C35,with n C（23） as the main peaks,and characteristic of single peak distribution. The n C21-/n C22 ＋values range from 0. 22 to 0. 74. The regular steranes have the predominance of C（29）,and few have the predominance of C（27）. In the C（27）-C（28）-C（29） diagram, most of them are mainly located in the mixed source area. The 1-methylphenanthrene/9-methylphenanthrene ratios range from 0. 77 to 9. 95,and 1,7-dimethylphenanthrene is also detected,which are associated with higher plants,indicating a predominant source of organic matter derived from terrigenous higher plants. However lower aquatic organisms have also contributed to hydrocarbon parent material.The Pr/Ph ratios range from 0. 83 to 1. 43. The distribution of fluorenes（ F）,dibenzofurans（ OF） and dibenzothiophenes（ SF） is summarized as follows： OF SF F,SF OF F or OF F SF. In the ΣSF/（ ΣF ＋ΣSF）-ΣOF/（ ΣF ＋ ΣOF） diagram,they mainly are projected near the oxidation-reduction environments which may be a weak oxidation-weak reduction environment,whereas some samples also fall into an oxidation lacustrine or in a coal environment. The OEP ratios of the source rocks ranging from 1. 01 ~ 1. 16,C（29）ααα20 S/ααα（ 20 S ＋ 20 R）ratios ranging from 0. 17 to 0. 45,C（29）αββ/（ ααα ＋ αββ） ratios ranging from 0. 27 to 0. 49,and the calculations of aromatic maturity parameters MPI1 and 4,6/1,4-DMDBT from the equivalent vitrinite reflectances show that the Carboniferous source rocks in the Zaduo Group are mature in organic matter.
作者
陈文彬
付修根
谭富文
曾胜强
冯兴雷
宋春彦
王东
CHEN Wen-bin1,2, FU Xiu-gen1,2, TAN Fu-wen1,2, ZENG Sheng-qiang1,2, FENG Xing-lei1,2, SONG Chun-yan1,2,WANG Dong1,2(1. Chengdu Center . China Geological Survey , Chengdu 610081 , Sichuan . China; 2. Key Laboratory of Sedimentary Basin and OH and Gas Resources,Ministry of Natural Resources,Chengdu 610081, Sichuan, China)
出处
《沉积与特提斯地质》
CAS
CSCD
2018年第2期14-22,共9页
Sedimentary Geology and Tethyan Geology
基金
国家油气专项"羌塘盆地金星湖-隆鄂尼地区油气资源战略调查"(DD20160159)资助
关键词
石炭系
烃源岩
生物标志物
芳烃
羌塘盆地
Carboniferous
source rock
biomarker
aromatic hydrocarbon
Qiangtang Basin
