At present, the most effective means of releasing the "water blocking damage" in the near-well zone is to change the wettability of the rock surface from liquid wetting to gas wetting. In this study, a novel nano wetting fluid was used to change the sandstone surface wettability aqueous phase from wetting phase to non-wetting phase. The adaptability of 0.5 wt% nano wetting fluid at different aging times, pH, salinity type, salinity and temperature was evaluated. The results show that 0.5 wt% nano wetting fluid has better adaptability under different conditions. The aqueous phase of the core surface can be changed from wetting phase to non-wetting phase; after adding nano wetting fluid, the drainage rate increased by 19.09%; at the same time, SEM characterization experiments showed that nano wetting fluid could achieve hydrophobic effect by changing the surface roughness of illite and chlorite.
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