
Fracture networks#
Fracture networks have an essential control on the hydraulic properties of rock masses. Research or exploitation of water, hydrothermal fluids, natural gas, and the characterization of reservoirs for carbon sequestration and hydrogen storage, all heavily rely on creating fracture models to understand the distribution of fractures and their properties in 3D space. This is achieved by creating Discrete Fracture Network (DFNs) based on stochastic algorithms. There are different DFN approaches provided by software:
All of these use many different parameters to drive the building of the model. The most important are summarized in the following table:

Summary table of the most important parameters used as input for DFNs. The distinction fracture network and fracture set identifies from where the property can be extracted.#
Structure of a fracture network#
Fracture networks can be subdivided in three main different components:
Nodes
Fractures
Boundaries

Subdivision of a simple fracture network#
Nodes
The nodes can be defined as the intersection points between two fractures (pertaining to the same or different set).
Fractures
Fractures are, unsurprisingly, the most important component of the three. We define as a fracture a generic discontinuity in a rock volume grouping. Fractures can be further divided into sets (i.e. fractures that have the same genetic origin and processes).
Boundaries
Finally the boundaries are defined as the observational limits that the interpreter imposes in the outcrop. We define these limits as interpretational boundaries. These delimit the areas of exposed rock where fractures can be measured and can be more than one. Boundaries can also present internal areas in which interpretation cannot be carried out defined as interpretational voids.