为明确陇东油田低渗油藏注水伤害机理，以长3储层为研究对象，构建了一套从储层内在因素到外在工程因素出发分析储层注水伤害机理的综合分析方法，采用X射线衍射（X-ray diffraction, XRD）、铸体薄片和扫描电镜（scanning electron microscopy, SEM）分析储层自身的岩石物性及孔隙结构，采用联合可视化微流控与核磁共振（nuclear magnetic resonance, NMR）的实验方法分析外来注入水对低渗油藏的伤害规律。结果表明：造成长3储层堵塞的内在因素是该层位储层属于低孔低渗储层，孔喉直径都是小于20 μm的小孔，储层物性较差，液相在储层中的渗流阻力较大，并且黏土矿物组成主要是高岭石与伊利石等速敏性矿物，易发生微粒运移而堵塞储层；造成堵塞的外在工程因素是注入水与地层水不配伍而产生垢体微粒，垢体微粒与黏土微粒会在孔喉通道处经历堵塞-突破的过程，导致注入压力波动式上升，同时注入水会携带垢体微粒与黏土微粒运移至油藏深部，在油藏深部聚集并加重堵塞，严重降低水驱的波及范围。研究成果明确了长3油藏的注水伤害规律，为油田注水开发提供了理论指导。

To clarify the mechanism of water injection damage in low-permeability reservoirs of the Longdong Oilfield, the Chang 3 reservoir was selected as the research subject. A comprehensive analysis method was developed, starting from the intrinsic factors of the reservoir to the external engineering factors, to analyze the mechanism of reservoir water injection damage. X-ray diffraction(XRD), cast thin sections, and scanning electron microscopy (SEM) were used to analyze the reservoir's rock physical properties and pore structure. Experimental methods combining visual microfluidics with nuclear magnetic resonance(NMR) were employed to analyze the damage patterns of externally injected water on low-permeability reservoirs. The results show that the intrinsic factors causing blockage in the Chang 3 reservoir are related to its low porosity and low permeability, with pore throat diameters all less than 20 μm, leading to poor reservoir properties and high liquid flow resistance in the reservoir. The composition of clay minerals mainly includes kaolinite and illite, which are velocity-sensitive minerals prone to fine particle migration and reservoir blockage. The external engineering factors causing blockage are the incompatibility of injected water with formation water, resulting in the formation of scale particle. These scale particles and clay particles can undergo a blockage-breakthrough process at the pore throat passages, causing fluctuating increases in injection pressure. Moreover, the injected water can carry scale and clay particles into the deep parts of the reservoir, where they accumulate and exacerbate blockage, significantly reducing the sweep efficiency of water flooding. The research results have clarified the pattern of water injection damage in the Chang 3 reservoir, providing theoretical guidance for water flooding development in oil fields.