Discrete fracture network (DFN) model simulations, where a fracture network can have a natural heterogeneity, is one of the most effective approaches in fluid flow analyses for naturally fractured and enhanced geothermal reservoirs. In the DFN model simulations, fractures are modeled by a pair of parallel smooth plates although real fractures have rough surfaces. Numerous field and laboratory o...

Fracture aperture change under stress has long been considered as one of primary causes of stress sensitivity of fractured gas reservoirs. However, little is known about the evolution of the morphology of fracture apertures on flow property in loading and unloading cycles. This paper reports a stress sensitivity experiment on carbonate core plugs in which Computed Tomography (CT) technology is ...

Larsson, M. 2012. Heterogeneity-Induced Channelling, Flow-Wetted Surface, and Modelling of Transport in Fractured Rock. Acta Universitatis Upsaliensis. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 971. 76 pp. Uppsala. ISBN 978-91-554-8468-2. Heterogeneities in fractured rock are found at all scales; from the scale of individual fractures, t...

[1] While permeability scaling of fractured media has been so far studied independently at the fractureand networkscales, we propose a numerical analysis of the combined effect of fracture-scale heterogeneities and the network-scale topology. The analysis is based on 2 10 discrete fracture network (DFNs) simulations performed with highly robust numerical methods. Fracture local apertures are di...

[1] A mechanistic model is presented to describe closure of a fracture mediated by pressure solution; closure controls permeability reduction and incorporates the serial processes of dissolution at contacting asperities, interfacial diffusion, and precipitation at the free face of fractures. These processes progress over a representative contacting asperity and define compaction at the macrosco...

Dispersion of solutes in a variable aperture fracture results from a combination of molecular diffusion and velocity variations in both the plane of the fracture (macrodispersion) and across the fracture aperture (Taylor dispersion). We use a combination of physical experiments and computational simulations to test a theoretical model in which the effective longitudinal dispersion coefficient D...

In pressure sensitive reservoirs, interaction effects among the porous media flow field, the fracture field and the stress field can cause some specific flow characteristics entirely different from those in conventional reservoirs. Dynamic fracture behavior is one of them, which generates a change in the value of fracture aperture and even a variation in the anisotropy of permeability. In this ...

Fracture characteristics—such as orientation, type, fluid storage capability, and permeability—are complex yet essential information for understanding fractured reservoirs. Fractures are often perceived as permeable pathways, although many fractures partially or completely inhibit permeability within a reservoir. For example, opening-mode fractures (joints) may be partially or entirely sealed h...

Previous studies have computed and modeled fluid flow through fractured rock with the parallel plate approach where the volumetric flow per unit width normal to the direction of flow is proportional to the cubed aperture between the plates, referred to as the traditional cubic law. When combined with the square root relationship of displacement to length scaling of opening-mode fractures, total...

We introduce a model that allows for the prediction of the permeability of self-affine rough channels (one-dimensional fracture) and two-dimensional fractures over a wide range of apertures. In the lubrication approximation, the permeability shows three different scaling regimes. For fractures with a large mean aperture or an aperture small enough to the permeability being close to disappearing...