四川盆地及周缘寒武系沧浪铺组沉积充填过程及油气地质意义  

Sedimentary flling process and petroleum geological significance of Cambrian Canglangpu Formation in Sichuan Basin and adjacent areas

作　　者：周刚 杨岱林 孙奕婷 严威 张亚 文华国[2] 和源 刘四兵[2] ZHOU Gang;YANG Dailin;SUN Yiting;YAN Wei;ZHANG Ya;WEN Huaguo;HE Yuan;LIU Sibing(Research Institute of Exploration and Development,PetroChina Southwest Oil&Gas Field Company,Chengdu 610041,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]中国石油西南油气田公司勘探开发研究院,成都610041 [2]油气藏地质及开发工程全国重点实验室(成都理工大学),成都610059

出　　处：《岩性油气藏》2024年第5期25-34,共10页Lithologic Reservoirs

基　　金：国家自然科学基金项目“扬子西北缘早古生代海相多幕次构造-沉积转换及其成烃成储响应”(编号:U2344209);中国石油天然气集团有限公司科技项目“四川盆地风险勘探领域和目标研究、工程技术攻关及现场试验”(编号:2023YQX10104)联合资助。

摘　　要：综合利用野外露头、钻井岩心分析、测录井及地震剖面等资料,对四川盆地及周缘寒武系沧浪铺组沉积充填过程开展了系统研究。研究结果表明:(1)四川盆地寒武系沧一段的沉积构造格局整体表现为“一隆、四洼、两高带”,岩性以碳酸盐岩为主;沧二段地层厚度差异性较小,区域地貌趋于均一,岩性以碎屑岩为主。(2)研究区寒武系沧一段沉积时期,平面上具有东西分异的沉积特征,主要受德阳—安岳古裂陷槽隔挡作用影响。裂陷槽西侧靠近物源区,主要发育混积潮坪沉积,裂陷槽东侧则广泛发育清水碳酸盐岩沉积;沧二段沉积时期,因裂陷槽隔挡作用减弱,全盆陆源碎屑沉积大幅增加,整体上以碎屑岩浅水陆棚沉积为主。(3)研究区寒武系沧一段优质白云岩储层以残余鲕粒云岩、砂屑云岩和粉晶云岩为主,宏观上颗粒滩的分布主要受到水下低隆和台洼边缘相对高部位控制,微观上储集空间主要受白云石化作用及溶蚀改造作用控制,发育粒内溶孔、粒间溶孔、晶间溶孔和晶间孔等孔隙类型,紧邻下伏筇竹寺组优质烃源岩,具有近源充注成藏的天然优势。Based on outcrops,drilling cores,logging and seismic data,the sedimentary filling process of Cambrian Canglangpu Formation in Sichuan Basin and adjacent areas were studied.The results show that:(1)The overall sedimentary structural pattern of the first member of Cambrian Canglangpu Formation(Cang-1 member)in Sichuan Basin presents“one uplift,four depressions,and two high zones”characteristics,with carbonate rocks as the main lithology.The second member of Canglangpu Formation(Cang-2 member)is gradually filled in,and the regional paleogeomorphology tend to be uniform,with clastic rocks being the main lithology.(2)During the sedimentary period of Cang-1 member in the study area,the barrier effects of Deyang-Anyue ancient rift trough led to an east-west differentiation sedimentary pattern in the plane.The western trough which is near the provenance,mainly developed mixed tidal flat deposits,while the eastern trough mainly developed carbonate deposits.During the sedimentary period of Cang-2 member,the barrier effects of trough was weakened,and the terrigenous debris significantly increased in the whole basin that were characterized by clastic rock shallow shelf deposits.(3)The high-quality dolomite reservoirs of Cang-1 member in the study area are mainly composed of residual oolitic dolomite,sandstone dolomite,and powder crystal dolomite.Macroscopically,the distribution of shoals is mainly controlled by underwater low uplift and relatively high parts of the platform depression edge.Microscopically,the reservoir space is mainly controlled by dolomitization and dissolution transformation,with intragranular dissolved pores,intergranular dissolved pores,and intercrystalline dissolved pores developed.It is adjacent to the high-quality source rocks of the underlying Qiongzhusi Formation and has an advantage of near-source filling and accumulation.

关 键 词：颗粒白云岩 古裂陷槽 混积潮坪 浅水陆棚 水下低隆 台洼边缘 近源成藏 沧浪铺组 寒武系 四川盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]