Pore Size Distribution of Rocks Determined by Mercury Intrusion Porosimetry

Abstract

Pore structure of rocks strongly influences permeability and other physical properties, therefore quantitative measurements of porosity and pore size distribution of rock samples are necessary and important in engineering geology. We collected total 108 rock samples of 15 rock types and measured their porosity and pore size distribution by the mercury intrusion porosimetry method and report the data and characterize the pore size distribution in this paper. Porosity and pore size distribution of rocks significantly vary with rock type, geological age and their locality. Moreover, the characteristics of pore size distribution did not show a unique correlation with the porosity of the same rock sample. Therefore, to evaluate pore size distribution of rocks is essential and useful for discussing fluid transportation related with rock pore structure. Mercury intrusion porosimetry is a useful method for pore size distribution measurements, and its reliability and repeatability were confirmed through this experimental study. For low-porosity（e.g. ＜1％）rocks, however, measured results of pore size distribution in large-size range（e.g. around 100μm）might have some error probably due to roughness of rock sample surfaces.