Controlling the rock property modeling method

With the Control Method form (model > Rock Properties > Control Method) you select and update modeling parameters for the modeling method that you assigned to your Volume of Interest. This workflow step opens automatically after Assign Method in case you assigned method 'Constant' to your VOI. For all other modeling methods, the workflow steps Transform and Trends and/or Variogram model are required first.

To control the modeling method parameters

  1. Open the Control Method form and select the rock property model from the Model drop-down list.
  2. In the Volume of Interest table, select the Volume of Interest (VOI). Upon selection, the right side of the form updates with the parameters related to the modeling method of the selected VOI. It is important that you review the default settings and update them if required.
    3. Using the context menu options Copy and Paste, you can copy-paste settings between the VOIs which have the same modeling method assigned. Once you have copied settings, you can select Paste Settings Options. This will open a separate form, which allows you to paste the settings to multiple VOIs at once. Note that checkbox selection can be done in bulk by holding down SHIFT while selecting a range of VOIs (they turn blue), then checking the box of one of them. All other VOIs in the selected range will get checked simultaneously.
  3. Click Apply and keep the form open, or click OK to go to the last step of the modeling workflow Run Model.

Parameters settings on the Control Method form

Constant  Type the value that you want to assign.

Uncertainty   This parameter can be propagated as a parametric uncertainty in a probabilistic volumetric calculation with the study strip. Click the uncertainty symbol behind the 'Constant' entry field to open the Uncertainty Parameter dialog. For how to use the controls on the dialog, see The Uncertainty Parameter dialog. For information about parametric uncertainties and how to use them in JewelSuite Subsurface Modeling, see Incorporating uncertainty in static or dynamic modeling.

Do not reset well cells to upscaled values  Ordinarily, the stochastic simulation is overwritten by the well data in the upscaled cells, to ensure that the well data is reproduced. You can turn this behavior off by checking this check box. If the upscaled property is set to 'None' on the Create Model form, this box is checked by default.

This method uses the inverse distance-weighted algorithm to interpolate the data.

Calculation  Select the dimensional space (2D or 3D) for the method to be applied. When you select 2D, the modeling algorithm only uses data from the same layer. When you select 3D, data from all layers is used.

Power  The power parameter controls how strongly the weight depends on the distance from each data point. Any value greater than zero is allowed. Values between 0.5 and 10 are recommended. The default value of 2 produces a smooth interpolation and is appropriate for most applications. Smaller values for the power parameter generate more equal weights and interpolations approximating a constant value with spikes at each data point. Larger values for the power parameter generate larger weights for nearby data points and interpolations approximating a nearest neighbor interpolation.

Do not reset well cells to upscaled values  Ordinarily, the stochastic simulation is overwritten by the well data in the upscaled cells, to ensure that the well data is reproduced. You can turn this behavior off by checking this check box. If the upscaled property is set to 'None' on the Create Model form, this box is checked by default.

Search factor  (Note: when the checkbox 'Use global kriging' was used on the Conditioning form (previous step of the workflow), the Search Factor is not used.) The variogram model ranges that you set on the Assign Variogram form (model > Rock Properties > Assign Variogram) are multiplied with the search factor to obtain the size of the search ellipsoid, i.e. Search ellipsoid = Search factor x Variogram model range. The search factor is applied to all three ranges of the variogram model so that the shape of the search ellipsoid reflects the spatial anisotropy.

Example: three different search factors applied to the same variogram model (major: 5000m, minor: 3000m, vertical: 500m).

  • Search factor = 1: Search ellipsoid = 5000m, 3000m, 500m
  • Search factor = 2: Search ellipsoid = 10000m, 6000m, 1000m
  • Search factor = 3: Search ellipsoid = 15000m, 9000m, 1500m

Do not reset well cells to upscaled values  Ordinarily, the stochastic simulation is overwritten by the well data in the upscaled cells, to ensure that the well data is reproduced. You can turn this behavior off by checking this check box. If the upscaled property is set to 'None' on the Create Model form, this box is checked by default.

Truncate Output

Minimum / Maximum  You can optionally set a minimum and maximum to restrict the range of the output data. Note that upon opening the form for the first time, the min and max of the upscaled property are shown. Once you manually overwrite these values, they will not return as the form will only remember the last entry. You can check the min/max values of the upscaled property by opening the Transform & Trends form and looking in the Statistics section of the dedicated Transform & Trends View (which opens simultaneously with the Transform& Trends from).

Set outliers to nearest bound  Values outside the range are given the min. or max. value of the data range you specified under Minimum / Maximum.

Set outliers to undefined  Values outside the data range you specified are given an ‘Undefined’ value.

Search factor  The variogram model ranges (model > Rock Properties > Assign Variogram) are multiplied with the search factor to obtain the size of the search ellipsoid, i.e. Search ellipsoid = Search factor x Variogram model range. The search factor is applied to all three ranges of the variogram model so that the shape of the search ellipsoid reflects the spatial anisotropy.

Example: three different search factors applied to the same variogram model (major: 5000m, minor: 3000m, vertical: 500m).

  • Search factor = 1: Search ellipsoid = 5000m, 3000m, 500m
  • Search factor = 2: Search ellipsoid = 10000m, 6000m, 1000m
  • Search factor = 3: Search ellipsoid = 15000m, 9000m, 1500m

Do not use upscaled values for conditioning  When this box is checked, the upscaled values are not used as control points (conditioning) in the stochastic simulation. You can use this option to generate an unconditional simulation that is not correlated with the well data.

Do not reset well cells to upscaled values  Ordinarily, the stochastic simulation is overwritten by the well data in the upscaled cells, to ensure that the well data is reproduced. You can turn this behavior off by checking this check box. If the upscaled property is set to 'None' on the Create Model form, this box is checked by default.

To achieve a fully unconditional simulation you must check both boxes.

Truncate Output

Minimum / Maximum  You can optionally set a minimum and maximum to restrict the range of the output data. Note that upon opening the form for the first time, the min and max of the upscaled property are shown. Once you manually overwrite these values, they will not return as the form will only remember the last entry. You can check the min/max values of the upscaled property by opening the Transform & Trends form and looking in the Statistics section of the dedicated Transform & Trends View (which opens simultaneously with the Transform& Trends from).

Set outliers to nearest bound  Values outside the range are given the min. or max. value of the data range you specified under Minimum / Maximum.

Set outliers to undefined  Values outside the data range you specified are given an ‘Undefined’ value.