3D PRINTING AND DIGITAL ROCK PHYSICS FOR SINGLE FRACTURE NETWORK

The mechanical and fluid flow properties in fractured and porous media are fundamental to predicting coupled multiphysics processes in the subsurface. Recent advances in experimental methods and multi-scale imaging capabilities have revolutionized our ability to quantitatively characterize geomaterials, which allows us to reach ever-increasing spatial resolution across scales. Digital rocks reconstructed from multiscale images (e.g., microCT images) and theoretical/stochastic generations are now routinely used to characterize petrophysical and mechanical properties across scales. 3D printing (i.e., additive manufacturing) is a fast-growing manufacturing technique that produces custom parts or whole products by printing materials by layers only where it is needed. For geoscience applications, 3D printing can be co-opted to print reproducible porous and fractured structures derived from CT-imaging of actual rocks and theoretical algorithms for experimental testing. The use of 3D printed microstructure allows us to overcome sample-to-sample heterogeneity that plague rock physics testing and to test material response independent from pore-structure variability. In this talk we will present coupled experimental and numerical analysis in a single fracture. The fracture in shale was first scanned using a microCT system and then the digital fracture network was printed using a stereolithography (SLA) method. In particular, we discuss the design of single fracture network and the progress of printing practices to reproduce the fracture network system. Printed samples at different scales are used to measure the permeability and surface roughness. Various numerical simulations including (non-)reactive transport cases are performed to study fluid flow characterization. We will also discuss the innovative advancement of 3D printing techniques applicable for coupled processes in the subsurface.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.