Software

FracWorks XP

FracWorks XP is the core of the FracMan package, providing the discrete feature geological simulations which form the basis for the discrete feature network (DFN) approach.

FracWorks XP generates three dimensional realizations of discrete feature geology using based on physically measurable parameters to produce geologically realistic discrete feature networks. FracWorks XP DFN models have been implemented for sites in sandstone, limestone/dolomite, siltstone, marl, and crystalline rocks. FracWorks XP also includes features for visualization, statistical analysis, simulated exploration, and simplified rock block, pathway, and network analysis.

Fracture Generation and Visualization

DFN modeling requires generation of 3D discrete features which effect engineering behavior at the scale of interest, which can very from a single meter of rock to hundreds of kilometers. FracWorks XP generates these features by combining

• Deterministic (known) features such as large scale faults and stratigraphic contacts
• Conditioned features which are combine known and statistical parameters, and
• Stochastic features which are known in only a statistical sense.

Fractures	Features
Deterministic	Specified Location, Shape, Orientation  Specified Hydraulic and Mechanical Properties
Conditioned	Location to Match Borehole or Trace Data  Transmissivity to Match Well Tests/Flow Logs  Specified or Stochastic Size, Shape, Orientation, Hydraulic, and Mechanical Properties  Conditioned to Geologic Models (StrataModel, 3D databases)
Stochastic	Stochastic Location Process (15 Available Models)  Stochastic Size, Intensity, Shape, and Orientation  Stochastic Hydraulic and Mechanical Properties

FracWorks XP fracture generation is based on user specified "sets" and "generation regions". Sets define groups of fractures with common statistical properties or geological genesis. "Generation regions" define the volume in which the fractures exist. Fractures may be stratabound within their generation region, or may extend beyond any given region.

FracWorks XP provides for editing of fracture geometric, hydraulic, and mechanical properties. Fracture visualization is provided through links to commercial and public domain visualization software (FracView). FracWorks XP discrete fracture models are saved as FracWorld (.FAB) format files, which can be read by all codes in the FracMan suite. FracWorld .FAB files are in ASCII or compressed ASCII format to facilitate interchange between PC and Unix platforms.

Simulated Exploration

FracWorks XP simulated exploration allows the user to place boreholes, cross-sections, and tunnels through the DFN model. Simulated exploration provides

• Stereoplots of fractures intersected by wells
• Simulated trace and lineament maps
• Simulated tunnel fracture maps
• Simulated well tests

Using FracWorks XP simulated exploration, the engineer can design and optimize planned site characterization activities. Simulated exploration features are also used to validate DFN models by demonstrating that the models are consistent with the field measurements which were used in FracSys to provide the parameters defining the DFN.

Statistical Analysis of Fracture Networks

FracWorks XP provides the following statistical measures of generated fracture networks:

• Fracture intensity
• Orientation distribution (Schmidt net stereoplots)
• Size distributions
• Distributions for hydraulic and mechanical properties
• Connectivity measures (intersection intensity)

Statistical reports describe the aggragate property of the the fracture sets and generation regions which combine to form a DFN model. These statistical reports are useful in comparing different sites, different geological assumptions, and different stochastic realizations.

Pathways, Networks, and Rock Blocks

PAWorks and FraCluster provide detailed analyses of pathways, networks, and rock blocks defined by FracWorks XP discrete feature networks. For convenience, simplified versions of these algorithms are provided within FracWorks XP.

• Pathways analysis searches through the fracture which connect specified pairs of boreholes or trace places, and describes the geometric and hydraulic properties of the pathways identified
• Network analysis uses graph theory to determine
  1. primary connections: the fractures directly connected to specified boreholes,
  2. secondary connections: fractures connected to the primary connections, and
  3. tertiary connections: fractures connected indirectly through connected networks
• Rock block analysis derives approximate measures for rock block volume, surface area, and radius distributions by extending rays into the fracture networks.

FracMan Program Modules