渤海海域低熟油特征及发育前景:以辽西南洼为例  

Characteristics and Development Prospect of Low-Mature Oil in Bohai Sea: A Case Study of South Liaoxi Depression

作　　者：李威 高玉飞 李友川 Li Wei;Gao Yufei;Li Youchuan(CNOOC Research Institute Co.Ltd.,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《地球科学》2025年第1期172-180,共9页Earth Science

基　　金：中海油重大专项(No.KJGG2021-0300);中海油研究总院科技课题(No.2020-KT-ZYZL-5);中海油青年科技与管理创新研究课题(No.JZTW2019KJ02)。

摘　　要：渤海湾盆地渤海海域油气地球化学参数显示部分构造带普遍发育低熟油气,但是一直被忽略而未系统开展低熟油气成因及资源潜力的研究.选取辽东湾坳陷作为研究对象,结合不同构造单元油藏,系统分析低熟油特征,研究烃源岩生成低熟油气的潜力和前景.结果表明:(1)辽东湾坳陷发育低熟油,其中以辽西南洼陡剖带油藏低熟油最为典型,具有高密度、高酸值、高胶质+沥青质的特征,奇偶优势明显,倍半萜烷系列完整,伽马蜡烷指数较高,与辽西凸起带、辽中中洼带油藏具有明显差异,低熟油主要来源于紧邻的辽西南洼咸水湖相烃源岩;(2)咸水烃源岩具有独特的双峰生排烃特征,在低成熟演化阶段就生成大量富含胶质、沥青质的液态烃,具备丰富的低熟油资源潜力和广阔前景.Organic geochemical analysis in Bohai Sea area of Bohai Bay Basin reveals that low-mature oil and gas are widely found in some structural belts,but the genesis and resource potential of low-mature oil and gas have been ignored and not systematically studied.Taking Liaodong Bay Depression as the research object,the characteristics of low-mature oil are systematically analyzed in combination with different structural unit reservoirs,and the potential and prospect of low-mature oil and gas generation from source rocks are studied.The results show that:(1)Low-mature oil is developed in the Liaodong Bay Depression.The reservoirs in the steep slope belt of South Liaoxi Depression are characterized as belonging to the typical low-mature oil reservoir,with the characteristics of the high density,high acid value,high colloid and high asphaltene,odd-even obvious advantages,and the C14-C16 sesquiterpenes series are complete,with higher gammacerane index.It is obviously different from the reservoirs in the Liaoxi uplift belt and the Liaozhong Depression,immature oil mainly source from saltwater lacustrine source rocks in South Liaoxi Depression.(2)The saltwater source rocks have unique characteristics of double peak hydrocarbon generation,and a large amount of liquid hydrocarbon rich in colloid and asphaltene is generated in the low mature evolution stage,which has rich potential and broad prospects of low mature oil resources.

关 键 词：渤海海域 辽东湾坳陷 低熟油藏 倍半萜烷 双峰生烃 石油地质学 

分 类 号：P618.13[天文地球—矿床学]