摘要
四川盆地基底隆-拗格局深刻影响并约束了沉积盆地岩相古地理演化特征,从而控制了盆地优质烃源岩及规模性储层的分布等关键石油地质条件.该研究通过收集和处理最新获得的四川盆地及周边区域98个固定台站以及近年布置的335个临时台站记录的104358条Pg,P和Pn纵波多震相地震走时数据资料,采用与多震相联合反演与双差地震定位新方法,重建了四川盆地0~30 km深度的高分辨三维纵波速度结构.地质-地球物理及油气勘探资料综合研究表明,在盆地西北和东北侧,分别存在成都—绵阳—广元—万源和万州—涪陵—赤水两个前寒武纪基底拗陷带,两者构成了一个向西南开口的“马蹄型”拗陷构造;而在盆地的中部和西南部,则存在遂宁—乐山—威信隆起带,并构成了一个“L型”隆起构造;盆地前寒武纪基底隆起与拗陷构造相互耦合,构成了四川盆地前寒武纪基底“两拗一隆”的隆拗格局新模式.855个油气钻井资料研究表明,超过90%的优质烃源岩分布在拗陷带或拗陷边坡带,同时,该隆拗格局新模式还约束了含油气盆地与规模性储层的分布.上述研究成果为四川盆地油气资源勘探提供了新的地球物理学证据,同时对于盆地油气资源潜力分析也具有十分重要的意义.
The Precambrian basement structure in the Sichuan Basin profoundly influences the sedimentary lithofacies and paleogeographic evolution,which is related to the distribution of source rocks,large-scale reservoirs,hydrocarbon migration pathways,and the development of a complete petroleum system.We have determined a high-resolution three-dimensional P-wave velocity model at 0~30 km depths to establish a comprehensive Precambrian basement structure in the Sichuan Basin.This model was constructed by a joint inversion algorithm of multiple seismic phases together with a double-difference relocation,utilizing an extensive dataset comprising 104358 travel time measurements of Pg,P,and Pn phases.These multi-phase travel times were recorded by a network of seismic stations consisting of 98 permanent and 335 temporary installations deployed in the Sichuan Basin and its surrounding regions.The imaging results reveal the presence of a Chengdu-Mianyang-Guangyuan-Wanyuan depression in the northwest and a Wanzhou-Fuling-Chishui depression in the Northeast of the basin,respectively,forming a horseshoe-shaped depression zone with a southwest opening.Meanwhile,a Suining-Leshan-Weixin uplift with a L-shaped tectonic belt has been developed to the center and southeast of the basin.The uplift and depression structures of the basin are coupled with each other,constituting a new pattern of the Precambrian basement in the Sichuan Basin.A spatial analysis of 855 oil and gas drilling data determined that over 90% of the hydrocarbon sources are distributed within the depression belt or its slope.The proposed“two-depression-one-uplift”basement pattern constrains the distribution of hydrocarbon-generating depressions and the occurrence of large-scale reservoirs in oil-bearing basins.The findings hold significant implications for assessing the hydrocarbon resource potential within the basin and provide novel geophysical evidence for exploring such resources in the Sichuan Basin.
作者
王剑
王志
杜秋定
沈利军
邬光辉
周刚
和源
温银宇
WANG Jian;WANG Zhi;DU QiuDing;SHEN LiJun;WU GuangHui;ZHOU Gang;HE Yuan;WEN YinYu(College of Earth Sciences and Technology,Southwest Petroleum University,Chengdu 610059,China;State Key Laboratory of Tropical Oceanology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China;Qiangtang Basin Research Institute,Southwest Petroleum University,Chengdu 610059,China;Laboratory of Ocean and Marginal Sea Geology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China;PetroChina Southwest Oil&Gas Field Company,Chengdu 610041,China)
出处
《地球物理学报》
北大核心
2025年第9期3401-3414,共14页
Chinese Journal of Geophysics
基金
中国石油-西南石油大学创新联合体科技合作项目(2020CX010100)
国家自然科学基金项目(92058210,42241206,U23B20154,42074047)联合资助.
关键词
四川盆地
前寒武纪基底结构
多震相联合反演
三维纵波速度模型
盆地隆拗新格局
Sichuan Basin
Precambrian basement structure
Multi-seismic phase joint inversion
Three-dimensional P-wave model
A new pattern of Basin uplift and depression
