Abstract: There are many parameters in the three-water model, including  cementation index, lithological parameters, and saturation index of free water pores of the three types of waters (free-water, micro-capillary water, and clay-bound water). These parameters are difficult to determine and have been plagued by the conductivity of the three waters. To solve the problem of low accuracy of logging reservoir parameters caused by low porosity， low permeability and uneven distribution of oil-water interface in  shale sandstone reservoirs in a block of a basin, the authors proposed a method to determine the cementation index and lithological parameters in the new three-water model equation when there are only rock electricity, mercury intrusion data, and cation exchange capacity experimental data, and further used the new three-water model to calculate its water saturation. To verify the feasibility of the parameters determined by the experimental statistical method in this paper, the reservoir interpretation and evaluation were carried out for  section 1 880~1 895 m of well XX  in the study area, and the parameters were brought into the new three-water model to calculate the water saturation, which was compared with the sealed coring water saturation. The results show that the calculated water saturation is consistent with the water saturation of sealed coring, which proves the accuracy of the parameters determined by the new three-water model. 

Key words: new three-water , model, low porosity and low permeability, experimental statistical method, saturation equation, new three-water model parameters