机构地区: 中国科学院地球化学研究所
出 处: 《沉积学报》 1991年第A12期1-8,共8页
摘 要: 本文报道了中国陆相原油的油源、时代和热历史等最新进展。陆相生油岩可以按地质环境条件划分为四个主要类型:A.中国板内大型湖泊盆地的沉积岩建造;B.断陷盆地湖相碎屑岩建造;C.断陷盆地—盐湖相膏盐—碎屑岩建造;D.山间盆地泻湖—湖泊相火山碎屑岩建造。研究了一系列代表性原油样。样品采自下列生油岩类型:1.淡水—半咸水湖相泥岩;2.含盐—膏盐相泥岩;3.湖相白云质泥岩;4.泻湖相—火山凝灰质泥岩。样品用气相色谱(GC)和色谱—质谱(GC/MS)分析,以揭示烷烃馏份中的生物标志化合物特征分布。简要地讨论了正烷烃、异戊二烯类、藿烷类以及其它生物标志化合物的分布。根据脂肪烃馏份生物标志化合物指标探讨了某些来源于膏盐和含盐泥岩的未成熟至准成熟原油的成因。江汉油田浅层产出的未成熟油和准成熟原油含有高含量的硫和含硫化合物,特别是烷基噻吩和四氢化噻吩,并呈现明显的偶碳优势。 This paper presents an overview on current thinking about sources, ages, and thermal histories of Chinese non-marine crude oils. Terrestrial source rocks, deposited under non-marine conditions in continental environments, have been divided into four major groups: Group A, sedimentary formations of big lake basins in the interior of the Chinese plate; Group B, lacustrine clastic formations in fault-bounded basins; Group C; salt lake evaporite- clastic formations in fault- bounded basins; and Gruop D, lagoonal- lacustrine volcano-clastic formations of intermontane basins. A number of representative crude oil samples were collected from the following four type of source rocks: (1) Lacustrine fresh-brackish water mudstones; (2) Saline to hypersaline mudstones; (3) Lacustrine dolomitic mudstones; (4) Lagoonal tufferous mudstones. The samples were analysed by GC and GC-MS to reveal the characteristic distributions of biological markers in their aliphatic fractions. The distribution of n-alkanes, isoprenoids, steranes and hopanoids as well as other biological marker compounds are discussed briefly. In terms of biological marker parameters of their aliphatic fractions, some immature to marginal mature oil samples sourced from hypersaline and saline mudstones are described. Immature or marginal mature crude oils occurred in shallow depth in Jianghan basin contain high amount of sulphur and organic sulphur compounds, especially abundant thiophene and thiolane homologues with remarkable even carbon number predominace.