松辽盆地古龙页岩油富集机制与常规—非常规油有序分布  

Gulong shale oil enrichment mechanism and orderly distribution of conventional-unconventional oils in the Cretaceous Qingshankou Formation,Songliao Basin,NE China

作　　者：张水昌[1,2] 张斌 王晓梅[1,2] 冯子辉 何坤[1,2] 王华建 付秀丽 柳宇柯[1,2] 杨春龙[1,2] ZHANG Shuichang;ZHANG Bin;WANG Xiaomei;FENG Zihui;HE Kun;WANG Huajian;FU Xiuli;LIU Yuke;YANG Chunlong(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;CNPC Key Laboratory of Petroleum Geochemistry,Beijing 100083,China;National Key Laboratory for Multi-resource Collaborated Green Development of Continental Shale Oil,Daqing 163712,China;PetroChina Daqing Oilfield Co.,Ltd.,Daqing 163712,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油天然气集团有限公司油气地球化学重点实验室,北京100083 [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163712

出　　处：《石油勘探与开发》2023年第5期911-923,共13页Petroleum Exploration and Development

基　　金：黑龙江省揭榜挂帅项目(2022-JS-1740,2022-JS-1853);中国石油天然气股份有限公司科学研究与技术研发项目(2021DJ1808)。

摘　　要：通过对松辽盆地白垩系青山口组黑色页岩有机质富集、生烃和成藏过程研究,揭示古龙页岩油富集机理及常规—非常规油气分布规律。松辽盆地是在早白垩世受西太平洋板块俯冲后撤影响、郯庐断裂带在中国东北地区发生大规模水平位移的背景上形成的一个巨大内陆湖盆。青山口组沉积期间,陆地水文循环强烈,松辽古湖盆湖平面上升,大量营养物输入使浮游菌藻类生物繁盛,间歇性海侵促进水体咸化分层和缺氧环境形成,有利于有机质富集;生物标志化合物分析表明,经微生物改造的浮游菌藻类生源有机质对高生油能力的优质烃源岩形成具有重要作用。松辽盆地古龙凹陷青山口组轻质页岩油层内富集具有4方面有利条件:①中等有机质丰度和高生油潜力为页岩油富集提供了充足的物质基础;②较高的热演化程度使得页岩油具有较高的气油比(GOR)和良好的可动性;③较低的排烃效率导致滞留在源岩中烃类含量高;④高成熟阶段的层内胶结封闭效应导致轻质页岩油高效聚集。成藏过程恢复表明,青山口组烃源岩早期中低成熟阶段生成的液态烃经二次运移后在长垣和斜坡聚集形成优质的常规油藏和致密油藏;后期中高成熟阶段生成的轻质油原地聚集,形成约150×10^(8) t的古龙页岩油资源,最终使盆地内地油气分布呈横向连片、垂向叠加、常规—非常规序次分布的特征,表现为常规油—致密油—页岩油有序聚集的完整“全油气系统”格局。Through the study of organic matter enrichment,hydrocarbon generation and accumulation process of black shale of the Cretaceous Qingshankou Formation in the Songliao Basin,the enrichment mechanism of Gulong shale oil and the distribution of conventional-unconventional oil are revealed.The Songliao Basin is a huge interior lake basin formed in the Early Cretaceous under the control of the subduction and retreat of the western Pacific plate and the massive horizontal displacement of the Tanlu Fault Zone in Northeast China.During the deposition of the Qingshankou Formation,strong terrestrial hydrological cycle led to the lake level rise of the ancient Songliao Basin and the input of a large amount of nutrients,resulting in planktonic bacteria and algae flourish.Intermittent seawater intrusion events promoted the formation of salinization stratification and anoxic environment in the lake,which were beneficial to the enrichment of organic matters.Biomarkers analysis confirms that the biogenic organic matter of planktonic bacteria and algae modified by microorganisms plays an important role in the formation of high-quality source rocks with high oil generation capability.There are four favorable conditions for the enrichment of light shale oil in the Qingshankou Formation of the Gulong Sag,Songliao Basin:the moderate organic matter abundance and high oil potential provide sufficient material basis for oil enrichment;high degree of thermal evolution makes shale oil have high GOR and good mobility;low hydrocarbon expulsion efficiency leads to a high content of retained hydrocarbons in the source rock;and the confinement effect of intra-layer cement in the high maturity stage induces the efficient accumulation of light shale oil.The restoration of hydrocarbon accumulation process suggests that liquid hydrocarbons generated in the early(low-medium maturity)stage of the Qingshankou Formation source rocks accumulated in placanticline and slope after long-distance secondary migration,forming high-quality conventional and tigh

关 键 词：松辽盆地 白垩系青山口组 古龙页岩油 有机碳库 常规/非常规有序聚集 断层封闭性 全油气系统 页岩油富集 

分 类 号：TE122.1[石油与天然气工程—油气勘探]