Calculation of saturation in Daqing Fuyang low permeability and porosity reservoirs

The complex pore structure of Daqing low permeability and porosity reservoir constraints the accuracy of saturation parameters. From the core analysis such as lithology and property we found that rocks in the mud and calcareous cementation is one important factor for the complex pore structure. Integrated with the occurrence of core oil, this factor also contributed to the poor condition of the oil reservoir. Based on the dual water saturation model, in this paper, we select the typical rock samples of Fuyang reservoir to test, for establishing the relationship between formation factor F with porosity, permeability, clay and calcium content, at the same time, according to the experiment to set up the relationship between saturation exponent n with porosity and permeability. So we can make the formation factor F and saturation exponent n more suitable for low permeability and porosity reservoirs of study area. Verified by coring well, the relative error of the calculation of saturation is 7.6%, meeting the requirements of actual production.