摘要
应用气相色谱、气相色谱-质谱技术,分析烃源岩的有机质来源、沉积环境、热演化程度等信息.研究表明:洪水庄组烃源岩样品的正构烷烃分布图(m/z85)以“前峰型”的单峰态分布为主,主峰碳多为nC_(18),表明有机质来源以低等生物为主.三环萜烷呈C_(20)或C_(23)为主峰的正态分布,C_(24)四环二萜/C_(26)三环萜烷比值分布于0.35~1.38,平均值为0.65,表明洪水庄组为低等生物输入.洪水庄组烃源岩甾烷呈现C_(27)甾烷占优势的“L”型,表明生烃母质来源为低等水生生物.Pr/Ph比值为0.16~0.85,植烷优势较明显,指示为强还原环境,少部分为还原环境.伽马蜡烷指数(Ga/C_(30)H)为0.06~0.66,平均值0.21,反映洪水庄组烃源岩形成于半咸水环境.甾烷C_(29)-αββ/(αββ+ααα)值介于0.26~0.46,平均为0.42,表明洪水庄组烃源岩多数处于成熟阶段.
Gas chromatography(GC)and gas chromatography-mass spectrometry(GC-MS)are used to analyze the organic matter sources,sedimentary environment and thermal evolution degree of source rocks.The results show that the distribution of n-alkanes(m/z85)of source rocks from Hongshuizhuang Formation is dominated by front peak type unimodel.The main peak carbon is mostly nC_(18),indicating the organic source is mainly lower organism.The tricyclic terpenes show a normal distribution with C_(20) or C_(23) as the main peak,and the ratio of C_(24)-tetracyclic diterpenes/C_(26) tricyclic terpenes is 0.35-1.38,averagely 0.65,indicating that there is input of lower organism in Hongshuizhuang Formation.The steranes show the dominant C_(27) sterane L-shape distribution,suggesting that the source of hydrocarbon generation material be lower aquatic organism.The Pr/Ph ratio is 0.16-0.85,with obvious phytane predominance,indicating a strong reducing environment and partially reducing environment.The gammacerane index(Ga/C_(30)H)is 0.06-0.66,averagely 0.21,reflecting the source rocks were formed in brackish water environment.The Sterane C_(29)-αββ/(αββ+ααα)is 0.26-0.46,averagely 0.42,showing the source rocks are mostly in the mature stage.
作者
宗文明
孙求实
郜晓勇
李永飞
石蕾
ZONG Wen-ming;SUN Qiu-shi;GAO Xiao-yong;LI Yong-fei;SHI Lei(Shenyang Center of China Geological Survey,Shenyang 110034,China)
出处
《地质与资源》
CAS
2023年第3期311-319,共9页
Geology and Resources
基金
中国地质调查局项目“冀北-辽西中新元古界油气地质调查”(DD20190098).
关键词
洪水庄组
烃源岩
生物标志化合物
辽西拗陷
Hongshuizhuang Formation
source rock
biomarker compound
Western Liaoning depression
