The Permeability Function Modeling workflow
Permeability Function Modeling is the first workflow among the two consecutive workflows in the Permeability strip (model > Permeability). The main purpose of this workflow is to enable you to define permeability as a depth continuous property. To do this, you can define permeability functions per facies class, by using correlations based on porosity and an optional additional property of interest.
In JewelSuite, the Permeability Function Modeling workflow starts with creating a new permeability function model. In the next steps, you assign rock properties (facies, porosity, an optional additional property), and finally you define permeability functions per facies class. The result is a permeability function model which you can use to create permeability logs. To continue further with the Permeability Property Modeling workflow, you use this function model as input to your permeability property model.
The Permeability Function Modeling workflow. click to enlarge
The result of the workflow is a Permeability Function Model which is a container holding all the associated metadata such as:
- Rock Properties The log sets of the rock properties (i.e. facies, porosity, an optional additional property) which are used to define the permeability functions.
- Permeability Functions The permeability functions defined per facies class.
Permeability modeling requires QC processes at two different levels:
- QC at Well Level Once you complete the Permeability Function Modeling workflow, you can QC your model at well level. You can create permeability logs and compare the modeled permeability (i.e. based on your permeability function model) against the permeability measured from cores or obtained from well test interpretation. This is to ensure that everything has proceeded as intended and that you are able to reproduce the expected permeability match.
- QC at 3D Grid Level The second QC step is performed once you complete the Permeability Property Modeling workflow.
Keep in mind that the permeability function model parameters can be scale dependent. When you create permeability logs for QC purposes, the resolution of the modeled permeability will depend on the resolution of the assigned input (on the Assign Data form). Since permeability is defined on a logarithmic scale, carefully consider the resolution of the assigned logs as they will determine the extreme high and low permeability values.
There also might be significant differences between the measured core permeability and the well test derived permeability values. This might be due to many factors such as: core sample not being representative of the reservoir heterogeneity, whether the samples being drilled parallel or perpendicular to bedding planes, the scale of the measurement, the thickness of the tested reservoir, whether the absolute or the effective permeability is determined, the overburden pressure, slippage effect of gas (i.e. Klinkenberg effect) etc.
The Permeability Function Modeling workflow consists of the following steps:
Creating a new permeability function model