Assigning rock properties

On the Rock Properties form (model > Saturation > Saturation Function Modeling > Rock Properties), you assign the logs of the rock properties that you will use in your saturation function. The assigned log sets are later used as input when you create saturation logs based on your saturation function model via the Saturation Logs tool (model > Saturation > Tools > Saturation Logs). In most cases, you assign a facies log to define saturation functions for each facies class. However, you can assign any discrete log to define the saturation functions based on its property classes. In the descriptions of the workflow steps, facies is used as an example.

Keep in mind that the saturation function model parameters can be scale dependent. When you create saturation logs for QC purposes, the resolution of the modeled Sw will depend on the resolution of the assigned input (on the Rock Properties form). You can assign either high resolution logs or their associated upscaled pseudo logs. Even though you apply the saturation function model at the grid cell level (via the Saturation Property Modeling workflow), you can validate its accuracy by comparing to high resolution logs or low resolution logs, i.e. upscaled logs.

To assign rock properties

  1. On the Rock Properties form, select the saturation function model from the Function model drop-down list.
  2. Select the log sets you want to assign from the drop-down lists. Assigning these log sets is optional.
    • Assigning a facies log from the 'Classes from' drop-down list enables you to define a saturation function per facies class. You can select any other discrete property here as well, then its property classes are used to define a saturation function.
      • If you select None, the entire interval is considered a single property class.
    • Assigning Porosity and/or Permeability logs enables you to define saturation function parameters as functions of porosity and/or permeability. See the Nested Functions on the Saturation Functions form for more details.
      • If you do not assign a Porosity log or a Permeability log, you cannot use these properties in the expressions you will define on the Saturation Functions form (via the Variable selection in the Nested Functions ). If you do assign logs, you must use them in the expressions. Otherwise, you will receive an error message as a pop-up window when you click Apply or OK on the Saturation Functions form.
    • Assigning a Net rock log allows you to ignore the non-net intervals. Non-net intervals will have undefined saturation values.
    Important   The log intervals with undefined facies, porosity, permeability values or zero net rock values will also have undefined saturation values.
  3. Click Apply to assign the rock properties and keep the form open, or click OK to assign the rock properties and proceed to the Fluid properties form.