Abstract:Through thin section,AxioVision image analysis,conventional core analysis,formation water testing and other methods,on the basis of clarifying the types of carbonate cements,multiple methods were used to calculate the content of carbonate cements,we were discussed the controlling factors for the different distribution of carbonate cement in the northern Chepaizi area of Junggar Basin (NCPZ area),and revealed its influence on the physical properties and oil—water distribution.Methods:Core samples were measured by gas porosity tester,gas permeability tester and carbonate content in rock tester,respectively.The detection environment temperature was 20 ℃ and humidity was 60%.The slices are dyed with alizarin red solution,and the carbonate cements is determined by using the AxioVision image analysis software of Zeiss Company.The main method is to use the image analysis multiplication method to mark the image points of carbonate cements through multiple scans,calculate the distribution content of carbonate cements in different visual fields of the image,and then calculate the content of carbonate cements in the sample points by numerical average.And at the same time,the casting thin sections were used to carry out the reservoir space analysis.The salinity,ion content and water type of formation water samples had been tested in Shengli oil field Company of Sinopec.The detection basis is oil and gas field water analysis method SY/t5523- 2006.Results: Research shows that a large number of early carbonate cements developed in the reservoirs of the study area,and filling part of the primary intergranular pores unevenly,showing strong heterogeneity.On the basis of convent calculate of carbonate cement in core,AxioVision image analysis with multiple times and multiple fields of view was used to supplement the calculation of carbonate cement content,and the relative error compared with the core measurement result was -0.14,which effectively compensated for the lack of core measurement data points.The content of carbonate cements has a different distribution characteristic of “high in the north and low in the south”on the plane.Carbonate cement is formed in a reducing environment with good sealing and alternating stagnation of water bodies,and directly precipitates in the pore water of sediments.There is a good positive correlation between the Ca2+ content of formation water and the content of carbonate cement.The difference Ca2+ determines the difference in the distribution of carbonate cement,and the difference Ca2+ is mainly controlled by paleomorphology.The water body in the palaeotectonic plateau is shallow and easy to accumulate Ca2+,and it’s a good place for CaCO3 precipitation.Microfacies play a certain control role in local well areas.Conclusions:The difference in carbonate cements results in the “double peak” characteristics of the reservoir properties in the study area,and creates a complex oil—water distribution relationship in high-viscosity and super-heavy oil reservoirs.