New Classification of Carbonate Rocks for Process-Based Pore-Scale Modeling

Summary Carbonate rocks are complex in structure and pore geometry and display heterogeneity on all length scales. In this paper, carbonate rocks are described on the basis of their contents and pore geometry for use in pore-scale modeling. Definitions of grains and porosities are based on other carbonate-rock classifications; we did not invent new concepts. On the basis of carbonate content (grain, mud, and cement), carbonate rocks were divided into three types: muddy, grainy, and mixed. Each type was divided into subtypes on the basis of pore geometries defined by other researchers. Pore-size distribution of Lønøy (2006) was used for each subtype. We review existing carbonate-rock models and suggest approaches, and show preliminary flow-simulation results, for pore-scale modeling of different grains, cement, and pore geometry in these complex rocks.