Abstract: Low resistivity pay zone includes two types of reservoirs, one is siltstone reservoir, the other is clayey sandstone reservoir. The resistvities of these two types of reservoir are similar to that of water layer because of high water saburation formed by strong capillary action and large inner surface area. After analysing the geologic characteristics of low resistivit pay zone in Jin 16 Block of Liaohe oilfeld, the author presented a method for discriminating low resistivity pay zone, that is, on the basis of forming conditions of pool and lithologic characteristics of reservoir, low resistivity pay zone can be identifed by using logging informnation and core data.

Key words: Low, Resistivity, Oil reservoir, Ireducible water saturation, Clay mineral, Surface area, Siltstone, Core analyses