Reservoir modelling sand-rich deep-water clastics: the necessity of down-scaling

Channels, lobes and levees are inadequate architectural elements to describe sand body geometry in sand-rich deep-water systems. Sand sheets are the most common architectural element. Elutriation modifies primary sedimentary structures by mobilizing and reorganizing grains. This changes pore size distribution and permeability characteristics. Bed amalgamation and offset stacking of sand sheets makes problematic the use of bed thickness in correlation. A down-scaling approach for reservoir modelling is recommended, as a hierarchy of architectural elements that define up-scaling relationships cannot be established.