Hello, I'm wondering if there's a way to differentiate gas-bearing and oil-bearing zones from resistivity log alone? Some of my seniors said that normally gas zone would have higher resistivity compared to the oil zone in the same formation. But if we look at the Archie's equation, the Rt is affected by only the Sw, which means that the hydrocarbon phase (gas or oil) does not have any effect on the Rt.
To make my question clear, let's say we have a gas-bearing formation and oil-bearing formation, both having the same Sw. Will the resistivity shows higher readings in gas zone? If so, what are the reasons for this?
Hope someone can enlighten me. TQ.
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