Modification of a 3D printer to create geologically realistic heterogeneous sand packs

There is a need to develop more accessible approaches to generate geologically realistic microheterogeneous structures in quasi-two-dimensional flow cells for use in light transmission experiments. In addition to automating the packing procedure to increase repeatability, such approaches would allow multiple researchers to investigate multiphase flow through similar heterogeneities across time and space. In this study, a three-dimensional (3D) printer was modified to accommodate a sand-filled hopper and used to create replicate packs that were similar to one another and to those produced in previous studies using a different apparatus. Replicate gas (CH4) injections were also used to assess the reproducibility of gas distributions in these replicate packs. Macroscopic features of the sand packs (bed height, number and location of laminae) and gas distributions (trapped gas volume, maximum gas width) were reproducible, but local-scale features of the gas distribution (gas pathway, ganglia-to-pool ratio) were more variable.

Automated summary

This study aims to develop a more accessible method for generating geologically realistic microheterogeneous structures for light transmission experiments. A 3D printer was modified and used to create replicate packs that were similar to those produced in previous studies. The reproducibility of gas distributions in these packs was also assessed. The results showed that macroscopic features of the sand packs and gas distributions were reproducible, but local-scale features of the gas distribution were more variable.