川西龙门山前带茅口组二段沉积特征储层形成机制及找矿前景  

Sedimentary Characteristics,Reservoir Formation Mechanism and Prospecting Prospects of the 2nd Member of Maokou Formation in the Longmen Mountain Front Zone of Western Sichuan

作　　者：徐康 汪远征[1,2] 蒋小琼 张庄[3] 孟宪武 潘文蕾[1,2] 宫晗凝[1,2] XU Kang;WANG Yuan-zheng;JIANG Xiao-qiong;ZHANG Zhuang;MENG Xian-wu;PAN Wen-lei;GONG Han-ning(Wuxi Research Institute of Petroleum Geology,SINOPEC,Wuxi 214126,China;Key Laboratory of Hydrocarbon Accumulation,SINOPEC,Wuxi 214126,China;Research Institute of Exploration and Development,Southwest Oilfield Company,SINOPEC,Chengdu 610041,China)

机构地区：[1]中国石化石油勘探开发研究院无锡石油地质研究所,无锡214126 [2]中国石化油气成藏重点实验室,无锡214126 [3]中国石化西南油气分公司勘探开发研究院,成都610041

出　　处：《科学技术与工程》2025年第5期1856-1869,共14页Science Technology and Engineering

基　　金：中石化科技部项目(P22073,P21042-5)。

摘　　要：四川盆地茅口组近年来多项勘探突破展现了较好的资源潜力。目前整体勘探程度低,沉积相类型及展布不清、储层特征及形成机制不明。以野外剖面、钻井、测井及地震资料为研究对象,利用岩心观察、常规及铸体薄片鉴定和孔渗测试等手段对川西龙门山前带茅口组二段沉积及储层特征进行了分析,并探讨了储层形成机制。研究表明:川西龙门山前带茅口组二段地层呈北西—南东向发育。龙门山南段和中段为茅二下亚段内缓坡边缘高能砂屑生屑滩发育区。茅二上亚段龙门山中段和北段发育高能云化台缘砂屑生屑滩。茅二上亚段储层岩性为残余生屑砂屑白云岩、含生屑晶粒白云岩和残余晶粒白云岩。茅二下亚段储层岩性主要为残余砂屑白云岩和残余晶粒白云岩。储集空间类型包括晶间溶孔、粒间溶孔、粒内溶孔及扩溶缝洞。茅二段整体为中薄层中低孔渗的Ⅱ、Ⅲ类孔隙型储层。高能滩相沉积构成储层发育的基础。准同生期大气淡水淋滤溶蚀作用是储层形成的关键。浅埋藏期白云石化作用使储层得以改善和保持。In recent years,multiple exploration breakthroughs have been made in the Maokou Formation of the Sichuan Basin.Currently,the overall exploration level is low.The type and distribution of sedimentary facies are still unclear.The characteristics and formation mechanism of the reservoir are unclear.Techniques such as core observation,pore permeability testing,conventional and cast thin section identification were used to clarify the sedimentary and reservoir characteristics of the 2nd Member of the Maokou Formation in the front of the Longmen Mountains in western Sichuan and to explore the main controlling factors of high-quality reservoirs.Research shows that the 2nd Member of the Maokou Formation in the front of Longmen Mountain in western Sichuan develops in a northwest southeast direction.The southern and middle sections of Longmen Mountain are the development areas of high-energy shoals of the lower sub section of the second section of Maokou Formation.The middle and northern sections of the Longmen Mountain in the upper sub section of the second section of the Maokou Formation are the development areas of high-energy dolomitized platform edge sand debris shoals.The reservoir lithology of the upper sub section of the Maokou Formation is mainly composed of residual bioclastic sandstone dolomite,bioclastic grain dolomite,and residual grain dolomite.The reservoir lithology of the lower sub section of the second section of the Maokou Formation is mainly composed of residual sandstone dolomite and residual grain dolomite.The storage space consists of intergranular dissolution pores,intergranular dissolution pores,intragranular dissolution pores,and expansion fracture pores.The second section of the Maokou Formation isⅡtoⅢporous reservoir.The reservoir foundation is composed of high-energy beach deposits.The leaching and dissolution of atmospheric fresh water during the contemporaneous period is the key to reservoir formation.The reservoir has been improved and maintained through shallow burial dolomitization.

关 键 词：四川盆地 川西地区 龙门山前带 茅口组二段 沉积特征 储层形成机制 

分 类 号：TE122[石油与天然气工程—油气勘探]