| Title | Discrete element modeling of rock fracturing using functional fluid |
|---|---|
| Authors | Ryu Wada |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | Fracturing, DEM, Functional fluid, Shear thickening fluid |
| Abstract | Fracturing has been widely used in the field of subsurface resource development to improve the permeability of the rock mass surrounding wells. Recent studies have suggested that the use of functional fluids could enable more efficient and adaptable fracturing. Under deep subsurface conditions such as high temperature and high pressure, it is often challenging to carry out any specialized operations. Therefore, the use of a functional fluid, which possesses functionalities itself, presents the potential to realize beneficial fracturing for resource development. For example, laboratory experiments on fracturing with shear thickening fluid (STF) have shown its potential to generate fractures in multiple directions, independent of crustal stress constraints (Mukuhira et al., IJRMMS, 2025). Since conventional hydraulic fracturing typically generates fractures along the direction of maximum principal stress, multi-directional fracture nucleation by using STF is more effective because it can enhance permeability in various directions. In this study, numerical simulations were conducted to investigate the mechanisms of unique fracturing phenomena with functional fluids. We focused on fracturing with STF, using an in-house discrete element method (DEM) code for modeling. STF is a non-Newtonian fluid whose viscosity increases nonlinearly with the flow and behaves like a solid under high shear rate conditions. We implemented this rheological behavior of STF into our fracturing simulation code. Through these DEM simulations, the mechanism behind multi-directional fracture nucleation by STF injection is partially understood. Ongoing work focuses on refining the modeling approach to achieve a more comprehensive understanding of STF fracturing. |