为了减轻传统稠化酸在碳酸盐岩多孔介质中的吸附滞留伤害，降低其对于致密碳酸盐岩改造后渗透率的伤害。提出采用阳离子表面活性剂遮蔽在岩石表面进行改性进而缓速的方式，以鄂尔多斯盆地马家沟组碳酸盐岩为研究对象，根据基本性质测试确定不同碳链长度阳离子表面活性剂界面改性能力，并利用分子模拟技术结合原子力显微镜、润湿角观测提出阳离子表面活性剂缓速机理，再通过动静态缓速性能测试和伤害评价实验研究阳离子表面活性剂缓速性能及地层伤害程度。研究结果表明：①碳链长度会影响表面活性剂分子吸附形态，进而改变其界面吸附效果，十四烷基三甲基氯化铵可在岩石表面形成直立致密吸附层，润湿改性效果最佳；②阳离子表面活性剂以界面吸附作用对岩石表面进行掩蔽覆盖，增加其疏水性能，阻碍H⁺接触到岩石表面，控制表面反应速率，达到缓速目的；③相较于常规酸，阳离子表面活性剂具有良好的动静态缓速性能，各项动力学参数降低50 %~60 %，减低了对碳酸盐岩孔喉伤害。研究认为：季铵盐阳离子表面活性剂具备分子量低、界面吸附能力强的优势，在保持缓速能力的同时，有效降低稠化酸对地层伤害程度；该项研究有助于认识表面活性剂缓速性能、改进缓速酸体系、提高碳酸盐岩储层改造效果等都具有积极的意义。

In order to reduce the damage of adsorption and retention of traditional gelled acid in carbonate porous media, and reduce the damage to permeability of dense carbonate rock after stimulation. It is proposed that the quaternary ammonium cationic surfactant can be adsorbed on the rock surface for modification and then show retarding performance. Taking the carbonate rock in Majiagou Formation of Ordos Basin as the research object, based on the basic property tests, the adsorption capacity of cationic surfactant with different carbon chain length is determined, and the retarding mechanism of cationic surfactant is proposed by using molecular simulation technology combined with atomic force microscope and wetting angle observation. Then, the retarding performance and formation damage degree of cationic surfactant are studied by dynamic/static retarding performance test and damage evaluation experiment. The research results show that: ① Carbon chain length affects the interfacial adsorption effect by changing the adsorption form of surfactant molecules. C₁₄TAC can form a vertical dense adsorption layer on the rock surface with the best wetting modification effect. ② The surface of rock is covered by cationic surfactant with interface adsorption, which can increase its hydrophobicity, prevent H⁺ from contacting the rock surface, control the surface reaction rate, and achieve the purpose of retardation. ③ Compared with conventional acids, cation surfactants have good actionic and static slow performance, the kinetic parameters are reduced by 50 %~60 %, reducing the damage to the carbonate orifice throat. It is concluded that the quaternary ammonium salt cationic surfactant has the advantages of low molecular weight and strong interfacial adsorption ability, while maintaining the retarding ability, and effectively reducing the damage of thickened acid to the formation. This study is helpful to understand the rapid performance of the surfactant, improve the slow acid system, and improve the effect of carbonate reservoir reformation. They are all of positive significance.