Abstract: The exploration practices of hydrocarbon-bearing basins in China show that low-resistivity reservoirs are of abundant reserves and high productivity as the important exploration areas for increase of reserves and production in oilfield. Also, they are the main targets for reviews of old wells. However, the complexity and diversity of low-resistivity geneses cause difficult logging evaluations. And the main control genesis-based logging evaluation techniques should be used. In view of the low-resistivity reservoir caused by the high irreducible water content, this paper presents a model for oil-water relative permeability based on percolation theory of multiphase fluids in porous media and lab experimental results, using multiple non-linear regression method, by which such a reservoir can be evaluated using oilwater relative permeability data, on the basis of exact determination of water saturation and irreducible water saturation. Case study indicates that this method is simple to use and makes the success ratio of interpretation greatly improved.

Key words: low-resistivity reservoir, relative permeability, irreducible water saturation, water saturation