华北北部地区蓟县系高于庄组-雾迷山组白云岩储层特征与形成主控因素

Characteristics of and main factors controlling the dolomite reservoir of Gaoyuzhuang-Wumishan Formations in the Jixian System, the north of North China

李朋威 何治亮 罗平 金廷福 张英 冯建赟 宋金民 徐士林

Pengwei Li Zhiliang He Ping Luo Tingfu Jin Ying Zhang Jianyun Feng Jinmin Song Shilin Xu

华北北部地区蓟县系高于庄组-雾迷山组白云岩储层以岩石与储集空间类型多样、孔隙结构与受控因素复杂以及非均质性强为特征，并由此制约了该区油气和地热等资源的勘探与开发。以野外露头和岩心为研究对象，开展了大量的野外地质考察、岩心观察、薄片鉴定与物性分析等研究工作，进一步总结分析了高于庄组-雾迷山组白云岩储层特征及其优质储层形成主控因素。研究结果表明，高于庄组-雾迷山组发育一套以微生物白云岩为主的储层类型，岩石结构构造复杂，其中，锥状叠层石和凝块石为其最有利的储集岩石类型。按照储集空间组合，可将储层划分为孔洞缝复合型、裂缝-孔隙型和孔隙型3种类型。其中，蓟县系雾迷山组白云岩储层以孔洞缝复合型为主，物性最好；高于庄组则以裂缝-孔隙型和孔隙型主，物性相对较差。综合分析认为，研究区高于庄组-雾迷山组规模优质白云岩储层是多种因素耦合作用的结果，其中微生物礁滩、印支期以来的构造隆升、破裂及溶蚀作用为其形成主控因素。

The dolomite reservoirs of Gaoyuzhuang-Wumishan Formations in North China are characterized by strong variety in reservoir rock types and pore space types, which are controlled by complex factors and caused strong heterogeneity in reservoir quality. They in turn seriously hinders the exploration and development of oil-gas and geothermal resources in this area. The study comprehensively analyzes and summarizes the characteristics of dolomite reservoirsand main factors controlling the formation of high-quality reservoirs in this area. Observations and studies are carried out on both outcrops and cores through large number of field geological surveys and core observation, thin section identification and physical property analyses. The results show that the reservoirs dominated by microbiological dolomites with complex textures and structures were developed herein, among which the coniform stromatolites and thrombolites are the most favorable rocks for reservoir. According to the pattern of reservoir space assemblages, the reservoirs could be categorized into 3 types:composite pore-cavity-fissure reservoir, fissure-pore reservoir and pore reservoir. Among them, the Wumishan Formation in the Jixian System are dominated by the composite pore-cavity-fissure type, relatively better in physical property. Whereas the Gaoyuzhuang Formation are of typical fissure-pore and pore types, relatively poorer in reservoir property. In conclusion, multiple factors contribute to the formation of large-scale high-quality dolomite reservoirs in the study area, with the microbiological reef-shoal facies, as well as the Indosinian tectonic uplifting, fracturing and dissolution, as the main factors leading to better reservoir quality.

10.11743/ogg20200103