Entering Assay and Pseudocomponent Data in OLI

Table of Contents

Objective

Option 1: Entering a PVT Analysis

• OLI Studio: Stream Analyzer
• OLI Studio: Stream Analyzer
• OLI Flowsheet: ESP

Option 2: Enter Pseudocomponent Data Directly

• OLI Studio: Stream Analyzer
• OLI Studio: ScaleChem
• OLI Flowsheet: ESP

Conclusion

Objective

Crude oils are constituted of many complex organic molecules for which individual component data is often unavailable. In OLI, a pseudocomponent is a unique inflow entry which enables the user to model properties of a crude oil based on existing aggregate fluid data. As a result, the information of thousands of hydrocarbon species can be converted to a few pseudocomponent entries. The crude oil properties may be defined based on a distillation curve, in which each boiling point range represents a molecular weight, density, solubility, and viscosity.

This article outlines the steps for creating a crude oil stream in OLI Studio: Stream Analyzer, OLI Studio: ScaleChem, and OLI Flowsheet: ESP, based on two data entry options.

Option 1: Entering a PVT Analysis

This modeling approach is suitable for a case in which the user has been provided with a PVT analysis.

OLI Studio: Stream Analyzer

1. Add a new Stream.
2. In the Inflows grid of the Definition tab, type the name of the assay, then press the <Shift + Enter> keys on the keyboard. (Please note: the assay name cannot be greater than 5 characters.)

3. Enter an Inflow value for the assay.
4. Select the Assay Data Type from the four distillation options.

5. Select the Average Bulk Density Type from the three options.

6. Enter the value for the bulk fluid density.
7. Enter the number of Distillation Curve Cuts.
8. Click the “Edit” button for the Distillation Data option. Enter the distillation data. The number of distillation data entries should match the number assigned in Step 7. Each entry in the Distillation Data window is considered an individual pseudcomponent, each with its own parameters and thermodynamic reference data.

Note: It may be helpful to select the Ctrl+C keys to copy data from another window, and select the Ctrl+V keys to paste the data in the Distillation Data table.

9. Lastly, select the Thermo Method from the four options to calculate the thermodynamic properties of the pseudocomponents.

10. After adding and running a Single Point calculation, the Output tab will include the calculated parameters for each pseudocomponent. Please click the “+” button for a pseudocomponent to view its calculated properties.

OLI Studio: ScaleChem

Assays can be defined for an Oil Analysis in OLI Studio: ScaleChem.

• Please navigate to the Assays tab of an Oil Analysis.
• Enter the name of the assay. (Please note: the assay name cannot be greater than 5 characters.)
• Enter the mole % concentration of the assay in the oil.
• Select the Assay Data Type from the four distillation options.
• Select the Thermo Method from the four options to calculate the thermodynamic properties of the pseudocomponents.
• Select the Average Bulk Density Type from the three options.
• Enter the value for the bulk fluid density.
• Enter the number of Distillation Curve Cuts.

• On the right side of the window, enter the distillation data. The number of distillation data entries should match the number assigned in Step 8. Each entry in the Distillation Data window is considered an individual pseudcomponent, each with its own parameters and thermodynamic reference data.

  Note: It may be helpful to select the Ctrl+C keys to copy data from another window, and select the Ctrl+V keys to paste the data in the Distillation Data table.

  • Click the Display Assay Cuts button to display the calculated parameters for each pseudocomponent.

The user may click each tab (“ASSAY_252K”, “ASSAY_308K”, etc.) to view additional calculated thermodynamic properties of each pseudocomponent.

OLI Flowsheet: ESP

1. Navigate to the Chemistry model.
2. There are two methods to enter an assay into OLI Flowsheet. The first is the same as in OLI Studio:
   • In the Inflows tab, type the name of the assay, then press the <Shift + Enter> keys on the keyboard. (Please note: in OLI Flowsheet: ESP, the assay name can be greater than 5 characters.)

• Alternatively (preferred), you can use the Add Button

• Click the Add button.

• For this example, we will select Add Assay

• Add the name of your assay

3. Select the Assay Data Type from the four distillation options.
4. Select the Average Bulk Density Type from the three options.
5. Enter the bulk fluid density.
6. Enter the number of Distillation Curve Cuts.

7. Click the “Edit” button for the Distillation Data option. Enter the distillation data. The number of distillation data entries should match the number assigned in Step 6. Each entry in the Distillation Data window is treated as an individual pseudocomponent, with its own parameters and thermodynamic reference data.

   Note: It may be helpful to select the Ctrl+C keys to copy data from another window, and select the Ctrl+V keys to paste the data in the Distillation Data table.

   

8. Lastly, select the Thermo Method from the four options to calculate the thermodynamic properties of the pseudocomponents.

Option 2: Enter Pseudocomponent Data Directly

In cases where the user does not have access to distillation data, the properties of a single pseudocomponent can be defined directly. At least two of the following properties must be specified: boiling point, specific gravity, or molecular weight. In the following example, the boiling point and specific gravity will be defined.

OLI Studio: Stream Analyzer

1. Add a new Stream.
2. In the Inflows grid of the Definition tab, type PC1, then press the <Ctrl + Enter> keys on the keyboard.
3. Repeat step 2 four times, assigning the following pseudocomponent names: PC2, PC3, PC4, and PC5.
4. Enter the following pseudocomponent information in the Inflows grid accordingly.

5. Note that the Calculated Properties can be located for each pseudocomponent by clicking the corresponding “+” button.

OLI Studio: ScaleChem

Individual pseudocomponents can be defined for an Oil Analysis in OLI Studio: ScaleChem.

1. Please navigate to the Pseudocomponents tab of an Oil Analysis.
2. Enter the following pseudocomponent information in the Inflows grid accordingly.

OLI Flowsheet: ESP

1. Navigate to the Chemistry model.
2. As with an assay, there are two methods to add a pseudocomponent In the Inflows tab, type the name of the pseudocomponent, then press the <Ctrl + Enter> keys on the keyboard.

Note: Please ensure the “PC14H10” species has not been selected as an Inflow.

Alternatively, use the Add button to add pseudocomponents.

3. Repeat step 2 four times, assigning the following pseudocomponent names: PC2, PC3, PC4, and PC5.
4. Enter the following pseudocomponent information in the Inflows grid accordingly.

5. For a specific stream in the Flowsheet tab, define the Inflow values for each pseudocomponent accordingly.

Conclusion

The pseudocomponent capability in OLI enables users to model complex crude oils based on a few data entries. For questions about entering your pseudocomponent data, please submit a ticket at support.olisystems.com.