Abstract
In this experiment, the resistivity variances of reservoir rocks such as sandstone, which had been prepared were examined under every confining air pressures.
As preliminary experiment, the comparisions between two electrode and four electrode method of resistivity measurement were studied on two samples under atmospheric pressure.
In the experiment concerning with change of resistivity under high pressure, core sample which are saturated with electrolitic solution was subjected to high pressure by air in autoclave and we measured the variations of resistivity at any pressure within 200kg/cm2 during pressure increased or decreased.
In this way, we could obtained the result that the resistivity variances were not so much and they were maximum 25% to minimum 5%. The relations between resistivity and pressure were looped by hysteresis and the variances were most intensive under 40kg/cm2 during pressure up and down until 200kg/cm2 in vessel. On the other hand, remaining saturattion variances of cores were less than about fifteen percent at this time.
