摘要
柴达木盆地北缘的侏罗系厚度巨大 ,其生油岩主要为深灰色泥岩、砂质泥岩和黑色碳质泥岩 ,并发育有煤层 ,侏罗系并非沉积于典型的沼泽成煤环境中 ,而是与滨浅湖相的泥质岩沉积有关。烃源岩中有机碳含量较高 ,但可溶有机质含量变化较大 ,并以低值为主。生烃潜力变化较大 ,可溶有机质转化率和烃转化率都比较低。干酪根类型主要为Ⅲ型 ,部分为Ⅱ型。有机显微组分主要是镜质组 ,其次是惰性组 ,而壳质组的含量则较低 ,因此 ,干酪根质量受到限制。综合考虑Tmax值、Ro 值以及OEP ,CPI和甾烷成熟度等参数 ,侏罗系的有机质成熟度因埋深不同而有差异。尽管有些有机质尚处于低成熟阶段 ,但大多正进入生油窗的最佳时期 。
The Jurassic in the northern margin areas of Qaidam basin has a huge thickness, in which the hydrocarbon source rocks are mainly dark\|gray mudstones, sandy mudstones and black carbargillites with coal beds. These source rocks mainly with kerogen of type III and partly with type II were deposited in an environment of lake beach or shallow lake. The amounts of organic carbon in the Jurassic source rocks are large. Their extractable organic matter (EOM) contents vary within a wide range, and the EOM contents of most samples are small. Therefore, hydrocarbon generation potentials of the Jurassic are different in different parts of the northern margin areas. The conversion ratios of EOM and hydrocarbon are both low. Macerals of the Jurassic source rocks are mainly vitrinite, inertinite comes second, and amount of exinite is relatively small, which indicates a poor quality of the kerogen. The values of \%T\-\{\%max\}, \%R\-\%o, \%OEP \%and \%CPI \%and maturity parameters of steranes show that the maturations of organic matter between different Jurassic samples collected from various depths are different. Though some of the Jurassic strata are still at lower maturation stage, most of them have entered “oil window\' and have not reached over\|mature stage.
出处
《石油大学学报（自然科学版）》
CSCD
2000年第1期64-68,共5页
Journal of the University of Petroleum,China(Edition of Natural Science)
基金
中国石油天然气集团公司"九五"勘探科技工程项目
关键词
柴达木盆地
侏罗系
烃源岩
地球化学特征
Qaidam basin
Jurassic
source rock
geochemical characteristic
