为系统研究老油田转注CO₂引起的储层伤害，采用室内实验评价手段，使用目标储层天然岩心和地层流体，开展了CO₂对储层物性及流体的影响研究。结果表明，目标储层主要矿物为铁白云石、斜长石和方解石，黏土成分主要是伊利石、绿泥石和伊/蒙混层；方解石的溶蚀主要表现为溶蚀晶锥的生成、断裂、破碎与消失，除了发生逆反应并无其他新物质生成；长石的溶蚀反应主要是在其表面生成了两类次生矿物，但溶蚀的量要大于新物质生成的量；与岩石作用初期表面有NaCl晶体生成及次生矿物沉淀，后期NaCl晶体消失，并有大量次生矿物生成；CO₂与原油接触后引起原油发生组分分异，降低了储层深部流体流动能力；注CO₂开发最终提高储层渗透率60%以上，使储集空间增加9.24%。研究成果合理地解释了油水井转注CO₂注气能力差异机理，理清了老油田转注CO₂注气能力主控因素，为老油田转注CO₂提高采收率提供重要技术支撑，同时也为国家碳减排项目的实施提供了重要参考。

In order to systematically study reservoir damage caused by CO₂ transfer in old oil fields, the effects of CO₂ on physical properties and fluids of the reservoir are studied by using natural cores and formation fluids of target reservoirs in laboratory experiments.The results show that main minerals in the target reservoir include iron dolomite, plagioclase and calcite, and clays in the target reservoir mainly include illite, chlorite and ironite/smectite.The dissolution of calcite is mainly characterized by the formation, fracture, fragmentation and disappearance of the dissolution cone, and there is no new substance formed except the reverse reaction.The dissolution reaction of feldspar mainly results in the formation of two types of secondary minerals on its surface, but the amount of dissolution is greater than that of new secondary minerals.In the early stage of interaction between CO₂ and rocks, NaCl crystals and secondary minerals form on the surface;In the later stage, NaCl crystals disappear and a large amount of secondary minerals form.Compositional differentiation of crude oil occurs after contacting with CO₂, which reduces the fluid flow capacity in deep reservoir.CO₂ injection has eventually increased the permeability of the reservoir by more than 60% and increased the reservoir space by 9.24%.The research results explain reasonably the difference mechanism of CO₂ gas injection capacity between oil and water wells, clarify the main controlling factors for CO₂ gas injection capacity in old oil fields, and provide important technical support for CO₂-EOR in old oil fields, as well as an important reference for the implementation of China's carbon emission reduction projects.