Calibrating direct flow simulations of rock samples

A method for calibrating a direct flow simulation of a rock sample, the method comprising the steps of:

• providing a 3D image of a rock sample, wherein the 3D image is comprised of a plurality of voxels;
• generating a segmented structural image of the rock sample from the 3D image by selecting each of the plurality of voxels to represent either a pore space or a solid material;
• simulating fluid flow on the segmented structural image with a direct flow simulation;
• generating a 3D spatially-resolved fluid velocity map for one or more fluid phases at a pore-scale resolution using pulsed field gradient nuclear magnetic resonance imaging;
• and
• comparing the simulated fluid flow and the 3D spatially-resolved fluid velocity map;
• thereby calibrating the direct flow simulation across the rock sample.