金羊盆地北票组沉积环境及烃源岩有机地球化学特征

基于钻井岩芯,结合实测剖面及收集的测试数据,以点及面,对金羊盆地北票组沉积环境及烃源岩有机地球化学特征进行了分析研究。结果表明:北票组烃源岩主要形成于淡水-微咸水、偏氧化的沉积环境中,且气候条件从潮湿、半潮湿到半干燥有序变化;综合评价认为,北票组烃源岩有机质丰度高,有机质类型主要为Ⅱ_2型,其次为Ⅲ型,处于成熟阶段及生油高峰期。横向上,位于章吉营子凹陷沉积中心的东坤头营子剖面及石门沟剖面有机质丰度最好,以中等-好烃源岩为主,而沉积边缘相的巴图营子乡刁家沟剖面有机质丰度最差,为非烃源岩-差烃源岩;纵向上,半深湖亚相的有机质丰度要好于滨浅湖亚相,辫状河三角洲、扇三角洲相为非烃源岩-差烃源岩。

Depositional environment and organic geochemical characteristics of source rocks of Beipiao Formation in Jinyang Basin

Based on the core, measured geological profiles, and testing data, the depositional environment and the organic geochemical characteristics of source rocks in the Beipiao Formation of the Jinyang Basin were analyzed. The results show that Beipiao Formation was deposited in freshwater-brackish water environment with partial oxidation,and the climatic changed from humid,semi-humid to semi-dry orderly. The sources rocks are in high abundance of organic matter, which mainly consists of type Ⅱ2 and some type Ⅲ organic matter. The source rocks are mature and are at the peak of oil generation. Laterally, sources rocks at the Dongkuntouyingzi geological profile and the Shimengou geological profile located in the depositional center of Zhangjiyingzi depression are with high organic matter abundance, and are defined as medium-good source rocks. The source rocks at Diaojiagou geological profile located at the marginal facies of deposition are the worst in terms of organic matter abundance, and are defined as non-poor source rocks. In vertical aspects, the semi-deep lake facies is better than shore-shallow lake facies in terms of organic matter abundance. Braided river delta and fan dalta facies are with non-poor source rocks.