Study on Characteristic Parameter of Microcosmic Pore Configuration in Low Permeability Oil Reservoirs

Discovered reserves of low permeability oil reservoirs is more and more presently, so they are in urgent need of exploit. The microcosmic pore structure of low permeability oil reservoirs with low porosity and low permeability characteristics is different from middling and high permeability oil reservoirs. And the microcosmic structure of rocks is an important factor affecting accumulating and flow characteristics of low permeability reservoirs. This paper studied the microcosmic pore structure and distribution of Hailaer low permeability oil reservoirs by using constant-rate mercury intrusion technology. This study shows that the pore radius is basically the same but the throat radius is different for cores of different permeability, and there is a very good correlation between the average throat radius and the permeability. This paper also analyzed the correlation between pore/throat radius ratio and permeability. On this basis, it is proposed that the average throat radius be used as an evaluation parameter of low-permeability oil reservoirs to characterize the degree of ease for oil flowing through the reservoirs. This study offers a reliable accordance for the scientific decision making in classification, evaluation and efficient development of low permeability oil reservoirs.