The Earth’s mantle (or, e.g., a glacier) involves a deformable solid matrix phase within which a second phase, a fluid, may form due to melting processes. The system is modeled as a dual-continuum mixture, with at each point of space the solid matrix being governed by a Stokes flow and the fluid melt, if it exists, being governed by Darcy’s law. This system is mathematically degenerate when the...

A new dual-porosity model is developed for singlephase flow in fractured/porous media. As in the commonly-used approach, flow is assumed to take place through the fracture network, and between the fractures and matrix blocks. The matrix blocks are treated in a lumped-parameter manner, with a single average pressure used for each matrix block. However, instead of assuming that fracture/matrix fl...

A model for two-phase, incompressible, immiscible fluid flow in a highly fractured porous medium is derived as a simplification of a much more detailed dual-porosity model. This simplified model has a nonlinear matrixfracture interaction, and it is more general than similar existing “transfer function” models. It is computationally less complex than the detailed model, and simulation results ar...

Fractures have crucial impact on flow in reservoirs. In naturally fractured reservoirs (NFR) the fracture network alone can be the dominant factor in fluid transport. Fractures as geological discontinuities introduce a high level of complexity into the entire reservoir modeling workflow. In current practice, the geological modeling of fractures and flow simulation are considerably disconnected,...

Reticulated porous ceramic (RPC) made of ceria are promising structures used in solar thermochemical redox cycles for splitting CO₂ and H₂O. They feature dual-scale porosity with mm-size pores for effective radiative heat transfer during reduction and µm-size pores within its struts for enhanced kinetics during oxidation. In this work, the detailed 3D digital representation of the complex dual-...

The state of the art of modeling fluid flow in shale reservoirs is dominated by dual porosity models which divide the reservoirs into matrix blocks that significantly contribute to fluid storage and fracture networks which principally control flow capacity. However, recent extensive microscopic studies reveal that there exist massive microand nanopore systems in shale matrices. Because of this,...

One of the most difficult tasks in reservoir simulations is reliable characterization of fractured subsurfaces. A typical situation in petroleum engineering employs dynamic data integrations such as the oil production history to be matched with simulated responses associated with a set of porosity and/or permeability fields. Among the challenges found in practice are proper mathematical modelin...

OBJECTIVE Reduced bone mineral density (BMD), assessed by Dual Energy X-ray absorptiometry (DXA), is a well-known risk factor for fragility fracture. A large proportion of patients with fracture have only slightly reduced BMD. Assessment of other bone structure features than BMD may improve identification of individuals at increased fracture risk. Digital X-ray radiogrammetry (DXR), which is a ...