Termit盆地上白垩统Yogou组烃源岩埋藏史、热演化史和生烃史模拟  

Simulation of burial history,thermal evolution history,and hydrocarbon generation history of the Upper Cretaceous Yogou Formation source rocks in the Termit Basin

作　　者：王涛 王洋 袁圣强[2] 毛凤军[2] 刘计国[2] 郭小文[1] 杨锐[1] Wang Tao;Wang Yang;Yuan Shengqiang;Mao Fengjun;Liu Jiguo;Guo Xiaowen;Yang Rui(Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education,China University of Geosciences(Wuhan),Wuhan 430074,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)

机构地区：[1]中国地质大学(武汉)构造与油气资源教育部重点实验室,武汉430074 [2]中国石油勘探开发研究院,北京100083

出　　处：《地质科技通报》2023年第6期151-161,共11页Bulletin of Geological Science and Technology

基　　金：中国石油科技创新基金项目(2020D-5007-0103)。

摘　　要：Yogou组烃源岩作为尼日尔Termit盆地晚白垩世重要的烃源岩层系,然而缺乏对该套地层的埋藏史、热演化史和生烃史的系统研究,制约了该地区油气成藏规律的认识。结合钻井、地震二维剖面及地球化学等资料,利用BasinMod盆地模拟软件中生烃动力学模型,恢复了Termit盆地Yogou组烃源岩热演化史,分析不同地区烃源岩的热演化特征及其与油气成藏的匹配关系,为Termit盆地下一步油气勘探提供了重要依据。研究表明,Termit盆地热流值具有明显的两段式演化特征,初始热流值较低,古近纪晚期热流值达到最大,热流值介于64.3~69.2 mW/m^(2)之间;新近纪以来,盆地热状态表现为持续冷却,现今热流值介于60.7~67.4 mW/m^(2)之间。Yogou组顶部烃源岩在55 Ma进入生烃门限(R_(o)=0.5%),达到生烃高峰(R_(o)=1.0%)的时间为35 Ma,在27.5 Ma进入高成熟演化阶段(R_(o)=1.3%)。Yogou组烃源岩存在2期生烃过程,晚白垩世末期(70~60 Ma)生烃阶段主要存在于盆地深凹陷区,古近纪(40~20 Ma)是全盆地主要的生烃阶段。盆地不同构造带对比发现,Dinga凹陷烃源岩具有成熟度更高,生烃时间更早和生烃能力更强等特征,可为Termit盆地储层提供充足油气来源。古近纪Termit盆地断裂强烈活动,促使底部烃源岩生成的油气在古近系储层中聚集成藏。研究成果为Termit盆地烃源岩生烃潜力评价提供依据,并为该盆地油气勘探提供理论指导。The Yogou Formation source rock is an important Late Cretaceous source rock series in Termit Basin,Niger.Due to the lack of systematic research on the burial history,thermal evolution history,and hydrocarbon generation history of this set of strata,the understanding of oil and gas accumulation rules in this area is restricted.In this paper,the thermal evolution history of the Yogou Formation source rocks in Termit Basin is restored by using the hydrocarbon generation dynamics model in BasinMod basin simulation software,combined with drilling wells,two-dimensional seismic profiles,and geochemical data.The thermal evolution characteristics of source rocks in different areas and their matching relationship with hydrocarbon accumulation are analysed,which provides important evidence for the next exploration of the Termit Basin.The results show that the heat flow value of Termit Basin has obvious two-stage evolution characteristics.The initial heat flow value is low and reaches maximum values in the Late Palaeogene(ranging from 64.3 to 69.2 mW/m^(2)).Since the Neogene,the thermal state of the basin has been characterized by continuous cooling,and the current heat flow value is between 60.7 and 67.4 mW/m^(2).The hydrocarbon generation of the top Yogou Formation began at 55 Ma(R_(o)=0.5%),and the main hydrocarbon generation window(R_(o)=1.0%)started at 35 Ma and reached a high maturity level(R_(o)=1.3%)at 27.5 Ma.Two stages of hydrocarbon generation are found in the source rocks of the Yogou Formation;in particular,the Late Cretaceous(70-60 Ma)hydrocarbon generation stage mainly exists in the deep area depression of the basin,while the Palaeogene(40-20 Ma)is the main hydrocarbon generation stage of the whole basin.Compared to different tectonic belts show that the source rocks of the Dinga Depression are characterized by high maturity,earlier hydrocarbon generation,and stronger hydrocarbon generation,which are beneficial for providing sufficient hydrocarbons.The strong activity of the Palaeogene faults led to the migrat

关 键 词：裂谷盆地 Termit盆地 烃源岩 盆地模拟 热演化史 

分 类 号：P618.13[天文地球—矿床学]