Experimental Study of Brine Concentration Effect on Reservoir Porosity and Permeability Measurement

Reservoir rock properties such as permeability and porosity can be determined using routine core analysis. However, the optimum brine concentration to determine these petrophysical properties with fluid saturation method has remained unattainable. Therefore, brine concentrations of 0.292 mol/L to 1.752 mol/L were used to assess the effect on reservoir porosity and permeability determination. Six (6) core samples with different diameters and lengths ranging from 2.51 cm to 3.78 cm and 4.48 cm to 10.81 cm respectively were used in the study. Result obtained depicts the effect of brine concentration has on reservoir porosity and permeability; as increased brine concentration resulted in decreased porosity and permeability values. However, stable porosity values were obtained from brine concentration of 1.168 mol / L in all the core plugs. The result further reveals a stable permeability value for core diameter and length of about 3.80 cm and 6.0 cm respectively from a brine concentration of 0.876 mol / L. Therefore, for routine core analysis, brine concentration range of 0.876 mol/L to 1.168 mol / L and core diameter and length of 3.80 cm and 6.0 cm can be used for the determination of reservoir rock porosity and permeability.