摘要
页岩油微运移是指石油由页岩层系中的富有机质层产生,并向其紧邻且孔渗性较好的贫有机质层发生短距离运移的现象。勘探实践显示,微运移可有效改善贫有机质层含油性及其品质,甚至优于部分富有机质页岩层系,是页岩油勘探突破的重要层段。因此,对页岩油微运移现象进行系统研究具有必要性。在回顾国内外已有研究基础之上,首先明确了页岩油微运移的示踪主要包括岩石热解参数、烃组分、生物标志化合物、非烃化合物、同位素等指标,基本原理是根据运移烃与滞留烃地球化学性质分异进行判别。分析表明,微运移会导致贫有机质页岩层系生烃活化能分散状分布,生烃门限偏早,且轻组分以游离态在贫有机质层中的聚集可进一步增加生油层和储油层烃组分分异程度,进而影响页岩含油性与可动性特征。基于油气运移及其地质色层效应,揭示了微运移贯穿油气生成、排出和滞留全过程,是连接页岩层系各个油气聚集要素的桥梁,影响了页岩油的差异富集。综合地球化学和地球物理方法是未来开展页岩层系中微运移精细识别的有效途径,将为揭示陆相页岩油动态差异富集提供新视角。
[Significance]The micromigration of shale oil refers to the phenomenon in which oil is generated in or-ganic-rich layers and expelled at short distances to adjacent,preferable porous and permeable,organic-lean layers in shale systems.Micromigration can effectively improve the oil content and quality of organic-lean layers,even surpassing some organic-rich shale layers based on the exploration practices.Therefore,it is necessary to conduct a systematic study on the micromigration phenomenon of shale oil.[Progress]Based on the current research pro-gress,this paper first identifies the main tracers of shale oil micromigration,which include rock pyrolysis parame-ters,hydrocarbon components,biomarkers,NSO compounds,as well as isotopes.The fundamental principle relies on fractionation between migrated hydrocarbons and retained hydrocarbons based on their geochemical properties.Analysis revealed that micromigration can lead to a dispersed distribution of hydrocarbon generation activation ener-gy in organic-lean shale layers,resulting in an earlier hydrocarbon generation threshold.Moreover,the accumula-tion of light hydrocarbons in a free state in organic-lean layers can further increase the difference of hydrocarbon components between generative units and in-source reservoirs,thereby affecting the oil-bearing and mobility charac-teristics of shale.Based on the effects of petroleum migration and geological zonation,this paper reveals that mi-cromigration occurs throughout the entire process of hydrocarbon generation,expulsion,and retention.It serves as a bridge connecting all elements of petroleum accumulation within shale systems,influencing the differential enrich-ment of shale oil.[Conclusions and Prospects]Comprehensive geochemical and geophysical methods are effec-tive ways to identify micromigration in shale systems and will provide a new perspective for revealing the dynamic differential enrichment of lacustrine shale oil.
作者
文杰
徐尚
苟启洋
赵同旭
王宇帆
刘秉昌
温康
WEN Jie;XU Shang∗;GOU Qiyang;ZHAO Tongxu;WANG Yufan;LIU Bingchang;WEN Kang(State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao Shandong 266580,China)
出处
《地质科技通报》
CAS
CSCD
北大核心
2024年第4期1-14,共14页
Bulletin of Geological Science and Technology
基金
国家自然科学基金优秀青年科学基金项目(42122017)
国家自然科学基金创新群体项目(41821002)
中国石油大学(华东)自主创新研究计划(21CX06001A)。
关键词
页岩油
微运移示踪
地球化学
页岩油富集
shale oil
micromigration tracing
geochemistry
enrichment of shale oil
作者简介
第一作者:文杰,E-mail:17844647408@163.com;通信作者:徐尚,E-mail:xushang0222@163.com。
