Set the Nugget on a Variogram Model

When constructing a variogram model, the first step is to set the nugget value. The nugget represents the small-scale variability of the data and is located just before the Y-intercept of the variogram model. You can do this either by clicking and dragging the nugget dragger directly on the variogram, or by entering a value in the Model tab. See Configure Model Settings.

Important: The nugget should always be set on the downhole variogram model (labelled Hole direction in the Project Tree), not on the directional models. The downhole variogram only uses sample pairs that share a contact within the same drillhole. As a result, these sample pairs should be the most closely related in the dataset and produce a more accurate nugget.

To set the nugget on the variogram model:

1. Click the variogram model in the Project Tree.
2. Click and drag the nugget dragger, labelled N, up or down the Y-axis to the desired location.

To set the nugget in the model tab:

1. Click the variogram model in the Project Tree.
2. Select the Model tab in the Property Panel.
3. Enter the Nugget value.

Note: Once the nugget is set on the downhole variogram, it is transferred to the rest of the directional variogram models. The nugget should not be changed on other models.