四川盆地加里东期构造运动幕次及油气地质意义  

Episodes of Caledonian movement and their significance for hydrocarbon accumulation in Sichuan Basin

作　　者：汪泽成[1] 谢武仁[1] 姜华[1] 苏旺[1] 黄士鹏[1] 谷明峰 马石玉[1] 施亦做 江青春[1] WANG Zecheng;XIE Wuren;JIANG Hua;SU Wang;HUANG Shipeng;GU Mingfeng;MA Shiyu;SHI Yizuo;JIANG Qingchun

机构地区：[1]中国石油勘探开发研究院 [2]中国石油杭州地质研究院

出　　处：《海相油气地质》2023年第4期349-359,共11页Marine Origin Petroleum Geology

基　　金：国家科技重大专项课题“下古生界-前寒武系碳酸盐岩油气成藏规律、关键技术及目标评价”(编号:2016ZX05004-001)资助。

摘　　要：加里东运动是我国南方地区早古生代重要的构造地质事件,与之相关的构造古地理演变及不整合面对下古生界油气地质有重要的影响。前人对加里东运动的研究偏重于华南地区,同期构造运动在上扬子地区的响应特征尚不明确。以四川盆地为例,充分利用钻井、地震信息,分析下古生界地层接触关系,厘定加里东期构造运动幕次及古隆起分布,分析构造运动对油气成藏要素与成藏过程的影响,评价有利勘探领域。研究表明,华南地区在早寒武世中晚期结束了伸展构造主导的兴凯运动旋回,进入挤压作用主导的加里东旋回。区域上加里东运动的3个幕次在四川盆地有明显响应:寒武纪末期的加里东运动Ⅰ幕(郁南运动)在川西北地区形成汉中—广元古隆起;晚奥陶世末期加里东运动Ⅱ幕(都匀运动)形成川中古隆起;志留纪末期的加里东运动Ⅲ幕(广西运动)导致川中古隆起最终定型。每一幕次构造运动经历了从“量变到质变”的渐进式演化过程,控制了地层、沉积相及不整合面的分布,进而控制了生储盖组合及储层展布。加里东期区内成盆演化与古隆起形成,造就碳酸盐岩储层常规天然气与页岩气两类天然气资源有序分布,围绕加里东古隆起形成了多层系立体规模成藏的大气区分布格局。Caledonian movement in Early Paleozoic is an important tectonic event in South China.The corresponding paleogeographic evolution and unconformities play an important role in hydrocarbon accumulation of Lower Paleozoic.Former studies of Caledonian movement focus on South China,and the limited study on corresponding characteristics of contemporaneous tectonic movement in the Upper Yangtze Craton restricted the understanding on its influence to the Lower Paleozoic hydrocarbon accumulation.Based on drilling and seismic data,this study analyzes the contact relationship of Lower Paleozoic,identifies the episodes of Caledonian movement and the development of paleouplifts,discusses the effects of such movements on hydrocarbon accumulation and evaluates the favorable exploration areas in Sichuan Basin.The results show that the extension-dominated Xingkai tectonic cycle ended and the Sichuan Basin entered the Caledonian tectonic cycle dominated by compression during mid-late Early Cambrian.The three episodes of Caledonian movements have obvious responses in Sichuan Basin:the EpisodeⅠ(Yunan movement)during the Late Cambrian developed the Hanzhong-Guangyuan paleouplift in the northwest of Sichuan Basin;the EpisodeⅡ(Duyun movement)during the Late Ordovician formed the central Sichuan paleouplift;the EpisodeⅢ(Guangxi movement)in the Late Silurian led to the final formation of the central Sichuan paleouplift with angular unconformity developing between the Permian and the underlying Sinian-Cambrian.Each episode has undergone a gradual evolution process from quantitative change to qualitative change,which controls the distribution of formations,sedimentary facies and unconformities,and thus determines the pattern of source-reservoir-caprock assemblage and reservoir distribution.The evolution of basin and the formation of paleouplift in the Caledonian period have resulted in the orderly distribution of conventional natural gas in carbonate reservoirs and shale gas resources,and a multi-layered,three-dimensional and bigscale

关 键 词：加里东运动 不整合面类型 古隆起 油气成藏 下古生界 四川盆地 

分 类 号：TE121.2[石油与天然气工程—油气勘探]