Crude descriptions
- Last UpdatedAug 14, 2026
- 1 minute read
Crude oil properties can be mathematically represented using a variety of different methods. In Assay crudes can be represented in two fundamentally different ways:
|
Representation |
Description |
Usage |
|---|---|---|
|
Model based |
Crudes are represented using a statistical model. With this representation, you can use Assay to extrapolate all properties of a crude based on a small sample of its properties. However, you cannot manipulate individual property curves of a crude when using this representation. |
You can use model based representations with both the AssaySynthesis and AssayUpdate Modules. When you work with a model based crude in AssaySynthesis or AssayUpdate, changes to one property of a crude potentially affect all properties of the crude. See AssaySynthesis, AssayUpdate. Model based representations may also be stored and viewed in the Database (). You cannot use model based representations in the AssayEditor. |
|
Profile based |
Crudes are represented using standard curve fitting methods. With this representation, you can use Assay to manipulate individual property curves of a crude. However, you cannot predict unmeasured properties of a crude when using this representation. |
You use profile based representations with the AssayEditor. When you work with a profile based crude in the AssayEditor, modifying the profile of one property of a crude does not affect any other properties of the crude. See AssayEditor. You may also store and view profile based representations in the Database. They are not used with AssaySynthesis or AssayUpdate. See How to use the database. By default, Assay employs the model based representation of crudes. |