TEST STUDY ON CORE RESISTIVITY IN DIRECT CURRENT ELECTRIC FIELD

The influencing tendency of salinity, oil saturation and confined pressure on core resistivity of saturated fluid is studied. Test shows that the core resistivity decreases with the increase of formation fluid salinity and the drop of oil saturation, while it increases with the gain of confined pressure. Formula Archie can only be used to describe how the salinity of formation fluid influence core resistivity, while it does little interpretation on the two factors of oil saturation and confined pressure. When the confined pressure is restricted in the core elasticity limitation, the pressure and core resistivity displays a linear relation for the cores from the same block.