Logging evaluation of low porosity and permeability reservoirs in the east of South Sea of China

Since the reservoirs in the east of South Sea of China are characterized by low porosity,low permeability,complex pore structure and high capillary bound water saturation,capillary bound water saturation and permeability are difficult to determine.In the paper a correlation analysis method is used to optimize the main parameters that influence capillary bound water saturation and permeability,and then multiple regression is used to establish capillary bound water saturation and permeability interpretation models.Considering the differences of electrical paths of free water and capillary bound water,and clay excess conductance,the water saturation model in low porosity and low permeability reservoirs is given based on the experimental results of rock electrical conductivity and symmetrical effective medium conductance theory.Practical application shows that the accuracy of determination of parameters is enhanced,and good results are achieved.