渤海湾盆地渤中26⁃6潜山油田油气异源混合成藏特征及充注过程  

Accumulation Characteristics and Charging Process of Heterogeneous Mixed Reservoir in Bozhong 26⁃6 Buried Hill Oilfield,Bohai Bay Basin

作　　者：官大勇 石文龙 赵弟江 张兴强 安俊睿 Guan Dayong;Shi Wenlong;Zhao Dijiang;Zhang Xingqiang;An Junrui(China National Offshore Oil Corporation(CNOOC)Ltd Tian Jin Branch,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《地球科学》2025年第2期478-493,共16页Earth Science

基　　金：“十四五”中海油集团公司科技重大专项“渤海复杂断陷盆地深层/超深层油气勘探关键技术研究”(No.KJGG2022-0401).

摘　　要：渤中26-6潜山油田位于渤海湾盆地渤中坳陷渤南低凸起西段,是继渤中19-6潜山凝析气田之后,渤海海域新发现的又一个亿吨级潜山油田,也是近年来中国近海取得的最大油气发现.为了解决该油田存在的成藏规律不清,特别是油气来源和成藏过程与模式尚不明确的问题,综合运用原油生物标志化合物、流体包裹体分析及烃源岩生烃模拟等方法进行了系统分析,取得以下几点创新性认识:(1)渤中26-6潜山油田原油与天然气具有异源特征,分别来自不同的凹陷,原油主要来源于黄河口凹陷沙三段,凝析气主要来自于渤中凹陷南次洼沙三段;(2)渤中26-6潜山油田明显经历了早期正常油(10~5 Ma)、中期凝析油气(5~0 Ma)、晚期轻质油(2.5~0 Ma)3期油气充注历程,中期与晚期流体充注规模较大,对渤中26-6油田的聚集成藏具有决定作用;(3)渤中凹陷南次洼与黄河口凹陷烃源岩生烃演化差异以及烃源岩与渤中26-6潜山接触关系的不同,造成渤中26-6不同区块成藏模式与流体相态的差异.上述认识对丰富潜山油气成藏规律、指导类似潜山油气勘探具有重要意义.Bozhong 26-6 Oilfield is located in the west section of Bonan Low Uplift,Bozhong Depression,Bohai Bay Basin.It is an another buried hill oil field newly discovered in Bohai Sea area with 100 million ton reserves after the exploration breakthrough of Bozhong 19-6 buried hill condensate gas field,is also the largest oil and gas discovery in China′s offshore waters in recent years.In response to solve unclear reservoir formation laws in the research area,especially the unclear source and accumulation process of oil and gas,this paper comprehensively uses the methods of crude oil physical property analysis,biomarkers,inclusion Petrography,homogenization temperature-paleosalinity and hydrocarbon generation simulation of source rocks,a systematic analysis was conducted,the results have shown that:(1)Bozhong 26-6 structure has different oil and gas sources,the characteristics of biomarker compounds indicate that crude oil mainly comes from the third member of the Shahejie Formation in the Huanghekou sag,however,condensate gas mainly comes from the third member of the Shahejie Formation in the southern subsag of the Bozhong Depression;(2)The Bozhong 26-6 oilfield has gone through three stages of oil and gas injection:early normal mature crude oil,middle condensate oil and gas(natural gas),and late light oil,The large scale of fluid filling in the middle and late stages plays a decisive role in the formation of reservoirs in the Bozhong 26-6 oilfield;(3)There are differences in hydrocarbon generation evolution between the source rocks in the Small sub depression in the southern part of Bozhong Depression and the Huanghekou Depression,and the contact relationship between the source rocks and the Bozhong 26-6 buried hill is different.therefore,this leads to differences in reservoir formation patterns and fluid phase states between different blocks in Bozhong 26-6.The above understanding and inspiration are of great significance for enriching the rules of buried hill oil and gas accumulation and guiding oil and gas explora

关 键 词：渤中26-6 潜山油气田 混合成藏 成藏特征 充注过程 石油地质 

分 类 号：P618.13[天文地球—矿床学]