Based on the abundant outcrops and 3D seismic data in Yuanba and its surrounding areas in northeastern Sichuan Basin, the characteristics, main controlling factors and development regularities of reservoirs in the fourth member of Sinian Dengying Formation (shortened as Deng 4 Member) were analyzed comprehensively. The results show that the reservoirs were mainly developed in microbial dolomite associated with the microbial mound and dolarenite associated with grain beach, and had intergranular dissolution pores, inter-frame dissolution pores and karst caves as main storage space. The reservoirs were large in scale and strong in heterogeneity. The analysis of the reservoir genetic mechanisms shows that the reservoirs in the fourth member of Dengying Formation were the products of karstification on mound-beach facies deposited in the second episode of Tongwan movement. The karstification had the marks of eogenetic karstification such as granophyric karst system and half-dissociation zone. The reservoirs were controlled by the sedimentary facies belt, the mound beach facies was the decisive factor in reservoir development. Further analysis indicates that the Yuanba area had a geological background of well-developed platform margin mound beach facies, so mound beach bodies can be taken as a favorable exploration target.

基于四川盆地东北缘元坝及其周边地区丰富的露头和3D地震资料，对震旦系灯影组第四段（简称邓4段）储层特征，主要控制因素和发育规律进行了综合分析。结果表明，该储集层主要发育于与微生物滩结合的微生物白云岩和与粮滩结合的白云岩，并以粒间溶蚀孔，框间溶蚀孔和岩溶溶洞为主要储集空间。储层规模大，非均质性强。对储层成因机理的分析表明，灯影组第四段储层是第二次桐湾运动沉积的滩滩相岩溶作用的产物。岩溶作用具有生代岩溶作用，如粒状岩溶系统和半离解带。储层受沉积相带控制，丘滩相是储集层发育的决定性因素。进一步的分析表明，元坝地区具有平台边缘丘滩相发育良好的地质背景，因此丘滩体可作为有利的勘探目标。储层受沉积相带控制，丘滩相是储集层发育的决定性因素。进一步的分析表明，元坝地区具有平台边缘丘滩相发育良好的地质背景，因此丘滩体可作为有利的勘探目标。储层受沉积相带控制，丘滩相是储集层发育的决定性因素。进一步的分析表明，元坝地区具有平台边缘丘滩相发育良好的地质背景，因此丘滩体可作为有利的勘探目标。