Geostatistics and Gridding

3-D Gridding Control Polylines

VIEWLOG includes tools that make it very easy to "control" or "bias" the gridding process. The user can simply draw a polyline on the map (either plan view or cross section), assign an elevation or concentration, and incorporate that polyline into the Kriging process. The gridding process will then honour those values along the polyline. This approach is much more efficient, and integrated, than simply adding "Ghost wells".

Database-Driven Geometry Layer Picking

Data points are passed directly from the database query to the gridding function, without the need for temporary XYZ ASCII files. In addition to the integrated well data editor, hydrostratigraphic units can be picked directly on the cross section.  All picks go directly into a database table. Finally, gridding can be performed either from the database or from contour lines and spot elevations stored in the map. R-Tree gridding allows data sets exceeding millions of data points.

Grid Equation Processor

The Grid Calculation option in VIEWLOG allows the user to write simple equations to edit, correct or change the gridded data. New gridded parameters can be generated, or existing grids can be modified by these one-line equations. An example application of this is to subtract one surface from another to produce an isopach map.  Features include:

  • Conditional expressions
  • Reprocessing of cells within selected polygons
  • Area, volume and mass calculations
  • Processing across multiple grid definitions
  • User can store frequently used equations

Advanced Gridding Techniques - Interpolation Methods

  • Triangulation
    • TIN
  • Nearest Neighbour (Theissen Polygon)
    • Weighted Average
    • Moving Average
  • Inverse Distance
    • Trend Analysis
    • Surface Fitting
  • Geostatistical Methods
    • Kriging and co-Kriging
      • 2-D and 3-D Kriging
      • Ordinary Kriging
      • Universal Kriging
      • Indicator Kriging
      • Co-Kriging
      • Polygon-limited gridding
      • Fault gridding (including scissor faults)