The N oil field in the South Turgai Basin of Kazakhstan is a carbonate rock ancient buried hill oil reservoir, and the carbonate rock is generally silicified. Comprehensive use of core, thin section, scanning electron microscope, well logging and other data to carry out relevant research. The results show that 69% of the core samples contain SiO2, with the content ranging from 0 to 89%, with an average of 47%. Silicification includes two forms: authigenic quartz filling dissolution pores and cryptocrystalline siliceous metasomatic carbonate rock. The types of ancient buried hill reservoir spaces can be divided into three categories: caves, fractures and pores. The physical properties of silicified carbonate rock reservoirs are better than those of non-silicified carbonate rocks. The physical properties of silicified carbonate rock reservoirs are related to the silica content. Positively related. Macroscopically, silicified carbonate rocks are most developed at the top of the ancient buried hill, and the degree of development weakens toward the interior of the buried hill. Core acidification experiments with different silica contents were carried out using HCL with a concentration of 15%. The results showed that the higher the silica content, the worse the acidification effect. When the siliceous content exceeded 78.5%, the reservoir permeability basically did not increase. This study provides a basis for layer selection for acidification measures in oil fields.