Based on analysis of core observation, thin sections, cathodoluminescence, scanning electron microscope (SEM), etc., and geochemical testing of stable carbon and oxygen isotopes composition, element content, fluid inclusions, and formation water, the fluid interaction mechanism and diagenetic reformation of fracture-pore basement reservoirs of epimetamorphic pyroclastic rock in the Beier Sag, Hailar Basin were studied. The results show that: (1) Two suites of reservoirs were developed in the basement, the weathering section and interior section, the interior section has a good reservoir zone reaching the standard of type I reservoir. (2) The secondary pores are formed by dissolution of carbonate minerals, feldspar, and tuff etc. (3) The diagenetic fluids include atmospheric freshwater, deep magmatic hydrothermal fluid, organic acids and hydrocarbon-bearing fluids. (4) The reservoir diagenetic reformation can be divided into four stages: initial consolidation, early supergene weathering-leaching, middle structural fracture-cementation-dissolution, and late organic acid-magmatic hydrothermal superimposed dissolution. Among them, the second and fourth stages are the stages for the formation of weathering crust and interior dissolution pore-cave reservoirs, respectively.

基于岩心观察，薄片，阴极发光，扫描电子显微镜（SEM）等的分析，以及稳定的碳和氧同位素组成，元素含量，流体包裹体和地层水的地球化学测试，流体相互作用机理和成岩作用改造研究了海拉尔盆地贝尔凹陷上准变质火山碎屑岩的裂孔基底储层特征。结果表明：（1）在地下室开发了两套储层，即风化段和内部段，内部段具有良好的储层区，达到了I类储层标准。（2）次生孔隙是由碳酸盐矿物，长石和凝灰岩等溶解形成的。（3）成岩流体包括大气淡水，深部岩浆热液，有机酸和含烃流体。（4）储层成岩改造可分为四个阶段：初期固结，早期表层风化浸出，中部构造裂缝-胶结-溶解，后期有机酸-岩浆热液叠加溶解。其中，第二和第四阶段分别是形成风化壳和内部溶蚀孔洞型油气藏的阶段。