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Version: 3.4.3

Discrete Fracture Network

Right-click commands for Discrete Fracture Network in the Interpretation Tree.

Source resources: IDR_IT_DFN.

Item Context Menu​

Right-click an individual discrete fracture network in the Interpretation Tree.

Actions​

  • Navigate To — Navigate to the item in the 3D view (ID_POPUP_ITEM_GOTO)

  • Regenerate — Re-run the stochastic generator for this DFN using the current per-set statistics and spatial model. Position and size samples change unless the RNG seed is held fixed. (ID_DFN_REGENERATE)

  • Grow — Regenerate then grow: extend tips under a default stress field using the propagation engine (step 0.5 m, max 50 m per tip, sigma1 oriented N-S) (ID_DFN_REGENERATE_GROW)

  • Delete — Delete this mesh from the project. (ID_POPUP_ITEM_DELETE)

  • Fracture Intersections — Compute the 3D fracture-fracture intersection line segments and build the connectivity graph (required before topology/connectivity attributes) (ID_DFN_FRACTUREINTERSECTIONS)

  • Mesh Intersections — Intersect the DFN against the visible outcrop mesh and store the resulting synthetic trace polylines on the DFN (used by scoring and synthetic-trace export) (ID_DFN_MESHINTERSECTIONS)

  • Truncate Against Boundary — Clip fractures so that they terminate at the domain boundary instead of extending beyond it (preserves observed P32 on truncated sets) (ID_DFN_TRUNCATEAGAINSTBOUNDARY)

  • Derive DFN Statistics... — Fit each fracture set's orientation, length and intensity statistics from measurements, in a dialog. The fractures themselves do not change, so VRGS offers to regenerate afterwards — otherwise the network on screen no longer follows from the statistics that describe it. Needs a DFN that already has sets. (ID_DFN_DERIVESTATS)

  • Model Surfaces... — Choose the bounding surfaces the network is confined between, so fractures are bed-confined rather than filling a box. Surfaces change both the model's shape and the volume its intensity is measured against, so VRGS offers to regenerate. See Implicit Surfaces for which surfaces are accepted. (ID_DFN_SETSURFACES)

  • Override P32 from Selected Traces... — Measure P21 (trace length per unit outcrop area) from the selected trace polylines, convert to P32 via the stereological factor, and replace each fracture set's intensity. Stores the source mesh name for provenance. (ID_DFN_OVERRIDEP32FROMTRACES)

  • Set Region Mask Source from Selection — Use the selected mesh, trace folder, or fault as a region-mask source for placement biasing. Fractures will be sampled with probability falling off as exp(-d^2/falloff^2) from the source geometry; clears the mask if no source is selected. (ID_DFN_SETREGIONMASKSOURCE)

  • Score DFN against Selected Traces... — Compare the DFN to observed traces and report a match score in 0..1. Combines a Kolmogorov-Smirnov length-distribution test, Fisher mean/K orientation distance, and a |P21_syn - P21_obs|/P21_obs intensity term as a weighted geometric mean. (ID_DFN_SCOREAGAINSTTRACES)

  • Re-derive from Source Orientation Groups — Re-run Fisher and length-distribution fits on the orientation groups originally used to build this DFN, then regenerate. Useful after editing the source groups or adding measurements. (ID_DFN_REDERIVEFROMSOURCES)

  • Show Outcrop-Constrained Fractures Only — Show only the fractures that actually cut the outcrop — the ones that would leave a trace, and so the ones directly comparable with your interpretation. The rest of the network is hidden, not removed. Available once the DFN has been cut against an outcrop by Mesh Intersections or Score DFN against Selected Traces...; the command explains itself rather than emptying the view if it has not. (ID_DFN_SHOWOUTCROPCONSTRAINED)

Export submenu​

  • Fractures to FAB... — Write the fracture geometry as a FracMan .fab file. (ID_DFN_EXPORT_FAB)
  • Set Statistics to CSV... — Write each fracture set's statistics to CSV. (ID_DFN_EXPORT_SETSTATS_CSV)
  • Fractures to CSV... — Write one row per fracture to CSV. (ID_DFN_EXPORT_FRACTURES_CSV)
  • Intersection Lines as Polylines — Turn the fracture–fracture intersection segments into polylines in the project. Run Fracture Intersections first, or there is nothing to export. (ID_DFN_EXPORT_INTERSECTIONS)

Analysis submenu​

  • Virtual Scanlines to CSV... — Run three virtual scanlines through the domain centre, one along each axis, and write raw and Terzaghi-corrected P10 per set to CSV. The counts and lengths also go to the Messages panel. (ID_DFN_ANALYSIS_SCANLINES)
  • Percolation Analysis — Cluster the network through its intersections and report how many fractures are isolated, how many clusters there are, how much of the network (by count and by area) the largest cluster holds, and whether it spans the domain in X, Y and Z. Needs Fracture Intersections first. (ID_DFN_ANALYSIS_PERCOLATION)
  • Oda Permeability Tensor... — Compute the Oda equivalent permeability tensor from the fracture geometry and a hydraulic aperture you supply in millimetres, using the cubic law. Reports P32, fracture porosity and the three principal permeabilities with their plunge and trend; the full tensor goes to the Messages panel. (ID_DFN_ANALYSIS_PERMEABILITY)
Oda assumes full connectivity

The Oda tensor is an upper bound: it sums fracture conductivities without asking whether they are connected. Run Percolation Analysis alongside it — a network that does not percolate will not deliver the permeability Oda reports.

See also​