摘要
歧口凹陷滨海斜坡沙一中亚段烃源岩评价和沉积环境研究薄弱,制约了油气勘探向海域拓展。基于滨海斜坡新钻揭的烃源岩样品,利用岩石热解、饱和烃色谱-质谱、元素录井技术等手段,对沙一中亚段烃源岩的地球化学特征、沉积环境和发育模式进行了系统研究。研究结果表明:滨海斜坡沙一中亚段烃源岩的总有机碳质量分数介于0.21%~8.61%,平均为2.41%,生烃潜量平均为9.73 mg/g,以好-优质烃源岩为主;有机质类型主要为Ⅱ1~Ⅱ2型干酪根;烃源岩镜质体反射率介于0.58%~1.32%,整体处于低熟-成熟阶段。滨海斜坡沙一中亚段烃源岩的有机质来源于陆生高等植物和水生生物混源,发育于弱氧化-弱还原的淡水湖盆环境,沉积时期湖盆水体较深,气候温暖潮湿,湖盆古生产力处于较高水平。滨海斜坡沙一中亚段烃源岩有机质类型较好,有机质丰度高,成熟度适中,湖盆沉积环境利于有机质的富集和保存,烃源岩生烃能力较强,具备勘探潜力。
[Objective]The geochemical characteristics and sedimentary environment of source rock in the Middle Section of Es1 in the Binhai slope have been insufficiently studied,limiting the potential for expanding hydrocarbon exploration into offshore areas.[Methods]In this study,newly drilled source rock samples from the Binhai slope were analyzed to systematically investigate the geochemical characteristics,depositional environments,and developmental models of source rock in the Middle Section of Es1.Techniques such as petrographic pyrolysis,gas chromatography-mass spectrometry(GC-MS)of saturates,and elemental logging were employed.[Results]The findings show that source rock in the Middle Section of Es1 in the Binhai slope predominantly contains typeⅡ1-Ⅱ2 kerogen,with total organic carbon w(TOC)contents ranging from 0.21%to 8.61%,an average w(TOC)of 2.41%,and an average(S1+S2)of 9.73 mg/g.The source rock can be classified as good to high quality.The source rock maturity ranges from low to mature,with Ro values between 0.58%and 1.32%.The organic matter is derived from a mixture of terrestrial plants and aquatic organisms,and the source rock formed in a freshwater environment with minimal oxidizing and reducing conditions.During the period of source rock deposition,the lake water was relatively deep,the climate was warm and humid,and the paleo-productivity was high.[Conclusion]The source rock in the Middle Section of Es1 in the Binhai slope contains high-quality organic matter with abundant organic content and moderate maturity.The sedimentary environment was conducive to the enrichment and preservation of organic material,indicating that the source rock have strong hydrocarbon generation potential and exploration value.
作者
朱华汇
陈家旭
张佼杨
张明振
石倩茹
董越崎
付东立
唐鹿鹿
ZHU Huahui;CHEN Jiaxu;ZHANG Jiaoyang;ZHANG Mingzhen;SHI Qianru;DONG Yueqi;FU Dongli;TANG Lulu(PetroChina Dagang Oilfield Company,Tianjin 300280,China)
出处
《地质科技通报》
北大核心
2025年第3期43-56,共14页
Bulletin of Geological Science and Technology
关键词
烃源岩
沉积环境
沙一中亚段
歧口凹陷
滨海斜坡
地球化学
source rock
sedimentary environment
Middle Section of Es1
Qikou Sag
Binhai slope
geochemistry
