四川盆地及周缘早寒武世龙王庙期岩相古地理特征与沉积模式  

Lithofacies paleogeographic characteristics and sedimentary model of the Early Cambrian Longwangmiao Formation in Sichuan Basin and its periphery

作　　者：张亚 张本健 李勇[2] 周刚 陈迪 梁金同 李成龙 蒋华川 龙虹宇 文华国[1,3] ZHANG Ya;ZHANG Benjian;LI Yong;ZHOU Gang;CHEN Di;LIANG Jintong;LI Chenglong;JIANG Huachuan;LONG Hongyu;WEN Huaguo(Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu,Sichuan 610059,China;Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation//Chengdu University of Technology,Chengdu,Sichuan 610059,China)

机构地区：[1]成都理工大学沉积地质研究院,四川省成都市610059 [2]中国石油西南油气田公司勘探开发研究院,四川省成都市610041 [3]油气藏地质及开发工程全国重点实验室·成都理工大学,四川省成都市610059

出　　处：《天然气工业》2025年第2期21-36,共16页Natural Gas Industry

基　　金：国家自然科学基金重点项目“扬子西北缘早古生代海相盆地多幕次构造—沉积转换及其成烃成储响应”(编号:U2344209);中国石油天然气股份有限公司科研项目“海相碳酸盐岩油气规模增储上产与勘探开发技术研究”(编号:2023ZZ16YJ01)。

摘　　要：四川盆地下寒武统龙王庙组是盆地油气勘探的重要层系,精细刻画其沉积特征及岩相古地理格局是进一步拓展盆地油气资源勘探的基础,也是建立盆地早期构造—沉积演化历史的关键。为此,利用四川盆地及周缘龙王庙组野外露头、盆内钻井以及地震等资料,系统总结了龙王庙组的沉积相类型及其沉积特征,在此基础上,通过定性与定量相结合的方法,恢复了四川盆地及周缘龙王庙组岩相古地理格局,建立了沉积模式,并最终明确了颗粒滩发育规律及控制机制。研究结果表明:①四川盆地及周缘龙王庙组一段为碳酸盐岩缓坡沉积体系,自西向东依次发育混积潮坪、浅水内缓坡、深水内缓坡、中缓坡、外缓坡和盆地等沉积相类型;②龙王庙组二段为碳酸盐岩弱镶边台地沉积体系,自西向东主要发育混积潮坪、局限台地、半局限台地、开阔台地、台地边缘、斜坡和盆地等沉积相类型;③龙王庙组颗粒滩体受控于古隆起、潟湖边缘和同沉积断裂3种控滩机制,其中膏质潟湖受华蓥山和齐岳山同沉积断裂控制;④龙王庙组沉积是一个由早期碳酸盐岩缓坡台地向晚期弱镶边台地演化的过程,晚期由同沉积断裂导致的生物礁丘快速建隆作用是控制该时期碳酸盐岩台地类型演化的关键。结论认为,四川盆地龙王庙组沉积演化新模式和3种控滩机制可为盆地深层—超深层海相碳酸盐岩油气勘探领域拓展和天然气规模增储上产提供重要的理论支撑。The Lower Cambrian Longwangmiao Formation is a potential reservoir for hydrocarbon exploration in the Sichuan Basin.The detailed characterization of its sedimentary characteristics and lithofacies paleogeographic pattern is fundamental to further exploration of oil and gas resources,and also crucial to establishing the early tectonic-sedimentary evolution history of the basin.Using the field outcrop,drilling and seismic data,this paper defines the sedimentary facies types and sedimentary characteristics of the Longwangmiao Formation in the Sichuan Basin and its periphery,combines qualitative and quantitative methods to restore the lithofacies paleogeographic pattern of the Longwangmiao Formation,and establishes its sedimentary model.Finally,the development pattern and control mechanism of granular shoal are clarified.The results are obtained in four aspects.First,the first member of Longwangmiao Formation records a carbonate ramp sedimentary system,and develops successively the sedimentary facies as follows(from west to east):mixed tidal flat,shallow-water inner ramp,deep-water inner ramp,middle ramp,outer ramp and basin.Second,the second member of the Longwangmiao Formation corresponds to a weakly-rimmed carbonate platform sedimentary system,and develops successively the sedimentary facies as follows(from west to east):mixed tidal flat,restricted platform,semi-restricted platform,open platform,platform margin,slope and basin.Third,the development of grain shoals in the Longwangmiao Formation is governed by three primary mechanisms:ancient uplifts,lagoon margins,and syn-sedimentary faults.Notably,the formation of gypsum lagoons is influenced by syn-sedimentary faults along the Huaying Mountain and Qiyue Mountain.Fourth,the sedimentary evolution of the Longwangmiao Formation represents a transition from an early-stage carbonate ramp platform to a late-stage weakly rimmed platform.In the later stage,rapid reef mound development driven by syn-sedimentary faulting is a crucial factor controlling the evolution of carb

关 键 词：四川盆地 下寒武统龙王庙组 沉积相 岩相古地理 控滩机制 沉积模式 勘探方向 

分 类 号：TE121.3[石油与天然气工程—油气勘探]