Evolution of pore size distribution of sandstone under dynamic loading [Slides

Abstract

explicitly explained by (1) a framework distribution of intergranular pores built up by sand-size grain packing followed by a subordinate toroidal void distribution around grain contacts, (2) a framework distribution of intergranular pores built up by matrix-size grain packing followed by a toroidal void distribution, and (3) intragrain pore-size distributions contained in mudrock fragments. The gradients and positions of segments are influenced by grain size sorting, roundness, and presence of matrix and porous fragments as well as by porosity types. The same conclusions are obtained in various arenites and wackes, whose shapes of cumulative pore-size distribution curves well correspond to rock types of sandstones. Thus, porosity properties such as intergranular porosities, matrix porosities and intragrain porosities of mudrock fragments can be quantitatively evaluated individually from analyses of pore-size distribution curves of sandstones. These values are in conformity with those estimated by point-counter analyses executed in thin sections and SEM images. Consequently, these porosity properties may indicate the degree of compaction undergone on sandstones during diagenesis.