松辽盆地北部青山口组富烃页岩形成环境与成因  

Formation environment and origin of hydrocarbon-rich shales in Qingshankou Formation, northern Songliao Basin

作　　者：付秀丽 李军辉[2,3] 郑强[2,3] 崔坤宁 王跃文[2,3] 贾琼 蒙启安[1,4] FU Xiuli;LI Junhui;ZHENG Qiang;CUI Kunning;WANG Yuewen;JIA Qiong;MENG Qi an(College of Geoscience,Northeast Petroleum University,Daqing 163318,Heilongjiang,China;Exploration and Development Research Institute of Daqing Oilfield Co.,Ltd.,Daqing 163712,Heilongjiang,China;Key Laboratory of Continental Shale Oil,Daqing 163712,Heilongjiang,China;Daqing Oilfield Co.,Ltd.,PetroChina,Daqing 163002,Heilongjiang,China)

机构地区：[1]东北石油大学地球科学学院,黑龙江大庆163318 [2]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712 [3]多资源协同陆相页岩油绿色开采全国重点实验室,黑龙江大庆163712 [4]中国石油大庆油田有限责任公司,黑龙江大庆163002

出　　处：《世界地质》2024年第1期19-36,共18页World Geology

基　　金：中国石油股份公司重大科技专项(2023ZZ15)。

摘　　要：通过古地温、古地貌、沉积环境定量恢复及地质事件综合研究,分析青山口组富烃页岩形成环境及成因。结果表明,松辽盆地青山口组富烃页岩R_(o)介于0.75%~1.60%,游离烃含量高,介于(4~12)mg/g,形成于古地温梯度(50~70)℃/km的高温热盆背景;在拉伸大地动力学及热沉降背景下形成了正断层密集断裂带控制的页岩层系,两凹一凸的古地貌为页岩形成演化提供富集场所;湖相温湿气候及岩浆热液为藻类繁殖成为厚层富烃页岩发育奠定物质基础;缺氧的半深湖—深湖还原—强还原环境有利于有机质埋藏。综合分析表明,构造、湖相沉积与古地温耦合作用奠定了富烃页岩的构造背景和热动力条件,温湿气候、缺氧环境及火山热液带来的营养物质是富烃页岩形成的重要原因。Comprehensive research involving quantitative restoration of paleo-geotherm,paleo-geomorphology,sedimentary environment,and geological events were conducted to study the formation environment and genesis of hydrocarbon-rich shales in the Qingshankou Formation of northern Songliao Basin.The results show that the R o of the hydrocarbon-rich shales in the Qingshankou Formation of Songliao Basin mainly ranges from 0.75%to 1.60%,with a high content of free hydrocarbons,mainly from 4 to 12 mg/g,formed under a high-temperature thermal basin background with a paleo-geothermal gradient of 50 to 70℃/km.Under the background of extensional geodynamics and thermal subsidence,shale layers controlled by densely fractured normal fault zones were formed.The paleo-geomorphology,characterized by two depressions and a protrusion,provided a conducive environment for the formation and evolution of these shales.The warm and humid climate of the lacustrine environment,along with magmatic hydrothermal fluids,laid the material foundation for the proliferation of algae,which was crucial for the development of thick layers of hydrocarbon-rich shales.The semi-deep lacustrine with oxygen deficiency,deep lake reduction,and strong reduction environment were conducive to the burial of organic matter.Comprehensive analysis indicates that the coupling effects of tectonics,lacustrine sedimentation,and paleo-geothermal conditions provided the tectonic background and thermodynamic conditions of hydrocarbon-rich shales.The warm and humid climate,anoxic environment,and nutrients brought by volcanic hydrothermal fluids are important reasons for the formation of hydrocarbon-rich shales.

关 键 词：富烃页岩 古地温梯度 构造演化 火山活动 沉积环境 青山口组 松辽盆地 

分 类 号：P618.13[天文地球—矿床学]