【摘要】 四川盆地震旦系上统灯影组岩性复杂、沉积微相精细刻画难度大，制约了对其中优质储层的准确预测。为了提高沉积微相划分的准确性，基于对旺1井岩心、薄片、常规和高质量成像测井等资料的综合分析，系统研究了川北地区灯影组四段白云岩沉积特征。研究结果表明：(1)川北地区旺1井灯四段发育台地边缘相和局限台地相，台地边缘相主要发育台缘丘、台缘滩和台缘丘滩复合体3种亚相及对应的6种微相类型，局限台地发育潮坪亚相，对应潮上坪和潮间云坪两种微相类型。(2)深电阻率、密度和自然伽马测井对台缘滩及潮坪亚相具有较好的识别效果，其中深电阻率对台缘滩指示意义较为明显，密度与自然伽马测井可有效区分潮上坪、潮间云坪及砂屑滩等微相；台缘丘及台缘丘滩复合体内部不同微相在常规测井交会空间中分布高度重叠，分辨能力明显受限。(3)台地边缘相中丘核与砂屑滩溶蚀孔洞发育，表现为暗色斑点特征，丘基与丘间呈线网状，丘坪以亮色斑点为主；局限台地中潮间云坪呈亮块状，局部见针孔状溶孔，潮上坪微相以线网状特征为主。(4)储层物性受岩性—沉积微相共同控制，强水动力条件下形成的藻凝块白云岩、藻叠层白云岩及砂屑白云岩原生孔隙较发育，并在早期溶蚀作用改造下进一步形成有利的储集空间；而弱水动力环境下形成的泥粉晶白云岩结构致密，不利于优质储层发育。结论认为，该项研究成果深化了对灯影组碳酸盐岩沉积相特征的认识，可以为四川盆地灯影组天然气勘探开发提供理论依据与技术指导。更多还原

【Abstract】 The Upper Sinian Dengying Formation in the Sichuan Basin is characterized by complex lithology and difficulty in fine depiction for sedimentary microfacies, constraining the accurate prediction of high-quality reservoirs. To improve the accuracy of sedimentary microfacies classification, the sedimentary characteristics of dolomites in the fourth member of Dengying Formation(Deng 4 Member) in the northern Sichuan Basin were systematically investigated, based on a comprehensive study integrating core observations, thin-section analysis, conventional logging and high-resolution image logging data from Well Wang 1. The following results are obtained.(i) The Deng 4 Member in Well Wang 1 develops both platform margin and restricted platform facies. The former comprise three subfacies: platform-margin mound, platform-margin shoal, and platform-margin mound-shoal complex, corresponding to six microfacies types. The latter mainly consist of tidal flat subfacies, including supratidal flat and intertidal dolomitic flat microfacies.(ii) Deep resistivity, density, and natural gamma-ray logs demonstrate good performance in identifying platform-margin shoal and tidal flat subfacies. Specifically, deep resistivity log is sensitive to platform-margin shoal, while density and natural gamma-ray logs effectively distinguish microfacies such as supratidal flat, intertidal dolomitic flat, and sandy shoal. However, different microfacies within platform-margin mounds and mound-shoal complexes exhibit significant overlap in conventional log intersection space, resulting in limited resolution.(iii) Dissolution pores and vugs are developed in mound cores and sandy shoals in platform-margin facies, appearing as dark spots, whereas mound bases and inter-mound areas display reticular patterns, and mound flats are dominated by bright spots. In restricted platform, intertidal dolomitic flats show bright massive features, with pinhole-like dissolution pores observed locally, while supratidal flats are characterized mainly by reticular patterns.(iv) Reservoir quality is jointly controlled by lithology and sedimentary microfacies. Algal clotted, algal stromatolitic, and arenaceous dolomites formed under strong hydrodynamic conditions retain relatively abundant primary pores, which are enhanced by early-stage dissolution to create favorable reservoir space. In contrast, micritic to microcrystalline dolomites formed under weak hydrodynamic conditions are relatively tight and unfavorable for the development of high-quality reservoirs. These findings enhance the understanding of sedimentary facies of the Sinian Dengying Formation carbonate rocks, and provide theoretical support and technical guidance for natural gas exploration and development of the Dengying Formation in the Sichuan Basin.更多还原