Accurate modelling of all scales of heterogeneities is necessary for a precise flow modelling inside clastic reservoir. We propose to simulate small scale heterogeneties that can be deposed at the interface between sedimentary structures (e.g. between accretion figure in channel point bars). The geometries of the considered sedimentary structures are modelled as boundary representation using the Non-Uniform Rational B-Spline (NURBS) mathematical formulation. This representation of various sedimentary objects (channel, point bar, clinoform, lobe and levee) provides a curvilinear framework for petrophysical properties simulations. The spatial distribution of petrophysical properties such as permeabilities has been simulated using unconditional Sequential Gaussian Simulations (SGS). An upscaling is then performed in order to integrate the surface properties into flow simulation grid. Nevertheless, these features are often very thin and local and cannot be upscaled to a complete reservoir grid cell. Thus, these interface small-scale disparities are considered as transmissibility multipliers applied to the faces of the grid’s cells. Moreover erosion due to the deposit of other geobodies can modify the repartition of surface heterogeneities. Thus, order of deposit and erosion between objects are taken into account through all these procedures.