angle u03b8 o increased to 45 u00b0 80 u00b0 spontaneous liquid imbibition into the air saturated cores was monitored at room temperature of about 20 u00b0 c it was performed by immersing the air saturated core in the liquid while hanging under an electronic balance the dynamic process of liquid imbibitions into the core was studied by recording the core weight gain with time the liquid saturation was calculated as the ratio of the amount of liquid imbibed into the core to the core pore volume where u03b4w l is the weight gain due to liquid imbibition and u03c1 l is the liquid density the effect of wettability modification was evaluated by comparing the liquid saturation vs time before and after treatment the imbibition rate decreased as the wettability is modified from liquid wetting to non wetting fluid flow tests were conducted to evaluate the effect of wettability modification fig3 shows the setup an overburden pressure of 6 9 u00d7 10 6 pa 1000 psig was applied by the syringe pump isco d series on the core inside the core holder temco type hch the temperature of the system was maintained by a universal oven memmert gas was injected from the compressed nitrogen cylinder or liquid injection from the inlet pump the inlet pressure and pressure drop were measured by the pressure transducers validyne engineering with the accuracy of u02dc 1 4 kpa 0 2 psia after calibration by the deadweight tester ametek a backup pressure regulator was used to adjust the pressure drop while measuring the gas flow rate by a flow meter in the range of 1 80 cm 3 sec with the accuracy of about 0 5 the liquid flow.