3D Modelling of Early Calcite Cements

We present a modelling framework for a 3D syntaxial and isopachous calcite cement growth model for carbonates. This model can be applied on images derived either by segmentation of thin sections or generated synthetically. In case of syntaxial cement, it consists of fitting the parallelepiped crystal shape over the carbonate grains and subsequently growing the cement within the crystal bounds. In case of the isopachous cement, a layer of precipitate is added on the surface of each grain. A non-linear relationship between porosity occlusion and permeability decrease is observed in models of carbonate deposit at various stages of cementation. Flow becomes more channelized and limited to a reduced number of pathways as cementation proceeds. An understanding of how different cement types influence the pore space geometry can therefore enable predictions as to drainage rate and recovery factors.