The Characteristics of Lognormal Distribution of Pore and Throat Size of a Low Permeability Core

The pore-throat size distributions (PTSDs) of low-permeability cores can be characterized by constant-rate mercury injection capillary pressure test (CMICPT), which can distinguish the pore and throat. The data from CMICPT of cores in X reservoir were analyzed. The result shows that the PTSDs are abided by lognormal distribution. The relationship between parameters α, σ of lognormal distribution of throat size in different cores and permeability is logarithmic, while those of pore size are unified. Finally, the reason why the distribution of throat size and pore size are lognormal distribution is discussed. The result will help deepen the understanding the relationship between pore structure and permeability of low-permeability reservoir.