摘要
六盘山盆地南部地区下白垩统地层中主要发育有3套烃源岩,自下而上分别为李洼峡组、马东山组和乃家河组。其岩性为灰色、灰黑色的湖相泥岩、灰质泥岩和泥灰岩。通过对盆地南部白垩系露头实测与取样,结合地震、钻井等资料,从有机质丰度、类型、成熟度及可溶组分的生物标志物等方面开展了地球化学特征研究,结合烃源岩生烃演化史分析,初步明确了六盘山盆地南部早白垩系烃源岩的生烃潜力。结果表明:六盘山盆地下白垩统烃源岩生烃高峰为早白垩世末期,生烃门限2150 m;李洼峡组烃源岩有机质成熟度较高,但有机质丰度较低,类型较差,勘探潜力有限;马东山组烃源岩有机质丰度较高,类型较好,分布较广泛,在一定条件下可以形成一定规模的低熟油;乃家河组烃源岩以Ⅱ型为主,成熟度偏低,处于未熟—低熟阶段。
The Lower Cretaceous strata in southern Liupanshan Basin mainly develops three sets of source rock series:Liwaxia Formation,Madongshan Formation and Naijiahe Formation from bottom to top.The lithology is gray and grayish black lacustrine mudstone,calcareous mudstone and marlstone.Geochemical characteristics are studied from the aspects of abundance,type,maturity and biomarkers of soluble components,through the field measurement and sampling of Cretaceous outcrops in the south of the basin,combined with seismic and drilling data,the hydrocarbon generation potential of Early Cretaceous source rocks in the south of Liupanshan Basin is preliminarily defined by analyzing the evolution history of hydrocarbon generation.The study shows that The peak of hydrocarbon generation of Lower Cretaceous source rocks in Liupanshan Basin is at the end of Early Cretaceous,the hydrocarbon generation threshold is 2150 m.the maturity of organic matter in source rocks of Liwaxia Formation is high,but the abundance of organic matter is low,the type is poor and the exploration potential is limited;The source rocks of Madongshan Formation have high abundance,good types and wide distribution of organic matter,which can form low mature oil of a certain scale under certain conditions;The source rocks of Naijiahe Formation are mainly typeⅡ,with low maturity and which are in immature⁃low maturity stage.
作者
蔡利飘
Cai Lipiao(Exploration and Development Research Institute of Shengli Oilfield Branch of Sinopec,Dongying,Shandong 257015)
出处
《地质科学》
CAS
CSCD
北大核心
2021年第4期1214-1226,共13页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
中国石化页岩油气资源评价及选区专项(编号:YYYQ⁃ZP⁃03)资助。
关键词
六盘山盆地
下白垩统
烃源岩
地球化学
Liupanshan Basin
The Lower Cretaceous
Source rock
Geochemistry
