Use of 3D-Printed Rock Analogues to Study Two-Phase Flow in Fractures
Creators: Lopez Saavedra, Sebastian
Publisher: name: University of Alberta Library
Year: 2024

<p>Flow through an individual rock fracture is of fundamental importance in both experimental and numerical studies aimed at describing the hydraulic behavior of fracture networks or rock masses. A single fracture can exert dominance over fluid pathways, and the results obtained from individual fracture studies can serve as a foundation for large-scale projects. However, rock discontinuities may present complex morphologies resulting from multiple factors, including mechanical and hydraulic conditions. These conditions determine the laws and models applicable to describe flow.<br>
Nevertheless, numerous divergent perspectives persist regarding several essential aspects of modeling single-phase flow and two-phase flow through an individual fracture. This investigation aimed to address some of these discrepancies and explore new areas, harnessing the capabilities of polyjet 3D printing technology. This technology facilitated the control of fracture roughness and mechanical conditions, visualization of flow displacements, and acquisition of local pressure measurements using fiber optic sensors.<br>
Additionally, it allowed for a preliminary experimental approximation of local fracture apertures, which were subsequently employed in numerical simulations of individual fractures.<br>
First, this study evaluated two methodologies for removing support material from polyjet 3D-printed samples.<br>
This technology may be instrumental in investigating flow through fractures, and consequently, the removal of support material from 3D-printed prototypes represents an obstacle to using such models in laboratory experiments. This study evaluated two methodologies for the removal of support material and investigated some of the effects of improving the removal of support material from 3D-printed prototypes and some of the implications of using these enhanced models in investigations of flow-through fractures.<br>
Second, with respect to single-phase flow, this study evaluated cubic-law-based models to provide insights for numerical simulation projects. Additionally, this research reported on the conditions under which cubic-law-based models are most suitable for estimating the experimental hydraulic conductivity of fractures. Furthermore, this investigation provided an approximation of experimental errors associated with the various methodologies for estimating the hydraulic aperture of fractures. On the other hand, the effectiveness of the cubic law in estimating the hydraulic conductivity of fractures was assessed. Lastly, this study addressed the criteria for determining the limit of the linear flow regime for fractures.<br>
Third, concerning two-phase immiscible flow, this study investigated how surface roughness and mechanical changes, including shear motion, impact dominant flow regimes. This is an area where the experimental data is very limited. Furthermore, this research investigated the shape of the relative permeability in fractures and examined the effects of roughness and shear deformation over two-phase flow displacements.</p>