Etudes in computational rock physics: Alterations and benchmarking

Abstract

We tested computational benchmarking data for the absolute permeability, electrical formation factor, and elastic moduli based on the Finney pack, a physical dense random pack of identical spheres digitally rendered into a 3D rectangular coordinate system, as the starting digital object. It is altered by (a) changing the radius of each sphere and (b) geometrically inverting these new packs by swapping grains and pores. Porosity, the absolute permeability, electrical formation factor, and elastic moduli are computed for all these alterations. The direct (grain-based) objects are relevant to clastic rock, and the inverse objects are proxies for carbonates with moldic pores. To corroborate these computational results, we matched the permeability versus porosity, formation factor versus porosity, and elastic moduli versus porosity trends they form by established theoretical rock physics models. These trends persisted when we reduced the scale of investigation by subsampling some of the digital objects under examination.