Abstract:The water sensitivity damage of well Mingnan 1 in tugerming section of North Kuqa structural belt is obviously different in the vertical direction. The study shows that the small layers mainly composed of Kizilnur formation (J1kz2), Yangxia formation (J1y3) and Ahe formation (J1a1, J1a2) show high water sensitivity damage. Combined with X-ray diffraction analysis, CT scanning and casting thin sections, the results show that the overall volume fraction of clay minerals in the reservoir group is in the range of 8.77% ~ 17.52%, the main reason for the damage of water sensitivity is the high clay content and a large number of dissolution particles. Based on the analysis of physical factors, the mercury removal rate and the radius of the pore throat gradually decreased with the depth of the well, and the connectivity of the pore throat in some small layers was poor. The above control factors show obvious difference in vertical direction, which is the main reason for the difference in vertical direction of water sensitivity damage in Minnan 1 well. In addition, through the clay stabilizer loss rate experiment, the two best choices to reduce the water sensitivity damage of Minnan 1 well were optimized. 3% YLN-07 was selected to prevent the loss of clay most effectively, and the clay loss rate was reduced by 14.97%. When economic benefits are taken into account, 0.5% HES clay stabilizer is the best choice, reducing the clay loss rate by 12.5%.