Abstract: Non⁃ionic surfactants, fluorinated cationic surfactants, and fluorocarbon polymers have been evaluated for their ability to alter wettability and injectivity in tight sandstone reservoirs through contact angle tests and injectability tests. The results showed that, compared with other chemical agents, the fluorocarbon polymer CRS⁃850 had better gas wetting inversion effect, and the contact angle of the core surface increases from 45.6° to 92.1°; the self⁃absorption of salt water before wettability changing was 0.360 8 g, the self⁃absorption after treatment dropped to 0.020 6 g, the core self⁃aspiration decreased by 98.85%, and the max self⁃suction rate decreased from 0.053 g/min to 0.002 g/min. The wet reversal agent increased the liquid⁃phase percolation capacity of the coreand the gas⁃driving permeation rate significantly, and the recovery effect of core gas drive permeability is remarkable, which increases by 501.69% to 673.91% on the basis of the gas flooding brine, indicating that the gas⁃wetting reverser has beneficial to remove liquid⁃phase damage in tight sandstone reservoirs.

Key words: Fluorocarbon nano?fluid, Contact angle, Injectability, Spontaneous imbibition, Core flooding

摘要： 通过接触角测试和可注入性实验对非离子型表面活性剂、含氟阳离子型表面活性剂、氟碳纳米液在致密砂岩储层的气润湿性改变能力和注入性进行评价。结果表明，相对于其他化学剂，氟碳纳米液CRS⁃850具有较好的气润湿反转效果，岩心表面接触角从45.6°增加到92.1°，由强水湿转变为气相润湿；处理前岩心自吸盐水量0.360 8 g，处理后自吸量下降至0.020 6 g，岩心自吸量下降幅度达98.85%。最大自吸速率从0.053 g/min下降至0.002 g/min；气润湿反转剂显著提高岩心内部液相渗流能力，增加气驱渗透率，岩心气驱渗透率恢复效果显著，在气驱盐水基础上提高了501.69%~673.91%，表明气润湿反转剂有利于致密砂岩储层解除液相伤害。

关键词: 氟碳纳米液, 　接触角, 　可注入性, 　自发渗吸, 　岩心驱替