Use AssayWorkup

The normal process for creating model-based crude descriptions using AssayWorkup is described in the following sequence:

1. Enter non-numeric information

   You can enter non-numeric information about the crude using the Information page. This page lists a number of properties associated with the crude being worked up in the document, such as name, reference and comments.

   

   The Information page contains all the fields and data present in the Crude Summary dialog available in the Database view for the crude currently being processed. See Crude summary dialog.

   Tip: The assay Name and Reference can be also edited directly from the document tab in the Navigator pane, by double-clicking the relevant field and entering the text directly into the field. See Document pages.

   When generating the crude, you can exploit any information provided about the origin and sample date of the crude by selecting the Origin and Sample Date check boxes respectively. Clearing the check boxes causes the crude origin and sample date to play no role in the generation process. By default, both check boxes are selected.

2. If required, select the basis crude

   AssayWorkup can optionally work with a basis crude, whose description is to be modified on the basis of the entered measurements.

   

   The Basis page allows you to select a basis crude which the assay is built upon. By assigning a basis crude you allow Assay to use a previous crude description as a starting point for generating the crude profile.

   To choose a basis crude, click the button and select the required crude from the list of database crudes in the Select Base Crude dialog box. To remove the selected base crude, click the button.

   Viewing the Base Crude on the Graph

   

   To show the basis crude on the profile graph along with the property profile for the generated assay, click the Graph Options icon on the graph toolbar and select Show Base Crude.

3. Enter measurement data into the measurement grid

   To enter measurement data for the crude, select the Measurements Page of the document. See Output grid.

   Enter your values into the grid, making use of the functionality of the grid as required to do so. See Enter data, Manipulate data in the grid and Additional features of the measurement grid.

4. Enter distillation data into the Measurement Grid

   

   Crude assay distillation data can be entered directly into AssayWorkup, as opposed to being entered in the Flowsheet Manager.

   Entering Distillation data directly

   To enter distillation data for a crude directly, select the Distillation Page of the Document. Enter your distillation data into the grid, making use of the functionality of the grid as required. See Enter data.

   Note that you can enter distillation data in AssayWorkup only via the Distillation Page. Distillation data should not be entered into AssayWorkup from any other measurement grid.

   Importing Crude Data

   Distillation data may be imported into AssayWorkup either by opening a crude from the database whose description contains distillation data, or by importing a crude whose AGF (.agf) or CDB file (.cdb) incorporates distillation measurements. In either case, the measurement grids in the Distillation and Measurement tabs will automatically be populated with the distillation and measurement grid data from the crude being imported, respectively. See Open existing assays as documents and Import crude data.

5. Enter GC data into the measurement grid

   

   Pure component data can be included in an AssayWorkup either by entering measurements directly, or by importing pure component data into AssayWorkup together with other crude data.

   Entering pure component data directly

   To enter pure component data for a crude directly, select the GC(Gas Chromatography) Tab located at the bottom left of the Assay workspace. Enter the GC data into the grid, making use of the functionality of the grid as required. See Enter data.

   Note that you can enter pure component data in AssayWorkup only via the GC tab measurement grid. Pure component data cannot be entered into AssayWorkup from any other measurement grid.

   Importing Crude Data

   Pure component data may be imported into AssayWorkup either by opening a crude from the Database whose description contains such data, or by importing a crude whose AGF ( .agf) or CDB file ( .cdb) incorporates pure component measurements. In either case, the measurement grids in the GC and Measurement tabs will automatically be populated with the pure component and measurement data from the crude being imported, respectively. See Open existing assays as documents and Import crude data.

6. If required, set up flowsheets for commercial fractionation

   You can use imperfectly fractionated streams by importing a flowsheet or defining a new one in the Flowsheet page.

   Note: You can only use crude independent flowsheets in the Flowsheet page of an assay document.

   To create a flowsheet, use the following toolbar buttons to create, move and delete units. See the help topics about the Flowsheet Manager for more information on how to set up a flowsheet. See Create a flowsheet.

   • - add a distillation unit. See Configure the number of distillation units in Create a flowsheet.

   • - add a mixer. See Add mixers and splitters in Create a flowsheet.

   • - add a splitter. See Add mixers and splitters in Create a flowsheet.

   • - move the selected process unit up.

   • - move the selected process unit down.

   • - remove the selected unit.

     To delete a flowsheet, click the button in the toolbar.

     To import an existing flowsheet you have two options:

   • Click the button to import a flowsheet from an external file.

   • Click the button and select Copy from Managed Flowsheet to copy a flowsheet from the Flowsheet Manager.

     

     The Crude Independent Flowsheets dialog box opens. Choose a flowsheet and click Select to import it. Click Manage to open the Flowsheet Manager (Create a Flowsheet) in case you want to create or edit a flowsheet in that environment before importing it.

     

     If you imported a flowsheet from the Flowsheet Manager, any changes you make in the Flowsheet page will not be automatically saved back to the Flowsheet Manager. To save a newly created or edited flowsheet, you have the following options:

   • Click the button to save the flowsheet to a file.

   • Click the button and select Copy to Managed Flowsheet to save the flowsheet to the Flowsheet Manager.

     Once you have created or imported a flowsheet, go to the Streams page, right-click and choose Add all flowsheet streams from the context menu.

     You can then use the flowsheet streams in the Measurements grid (Enter Data). Double click a column or row header (depending on whether the grid is transposed or not) and click the arrow icon to reveal a list of available streams.

     

     After defining a flowsheet and adding its streams to the Measurements grid, it is possible to associate assay data with these streams. If distillation data (i.e. D86, D1160 or Simdis) are included in the Measurements grid, the flowsheet parameters will be automatically calculated during assay generation.

     To prevent automatic flowsheet fitting from changing a flowsheet parameter, click the Lock Parameter icon next to the parameter in the Flowsheet page. The icon changes to a locked padlock . Note that you can still manually edit the value. Click the icon again to unlock the entry and refit the distillation unit data.

     To lock all parameters for a distillation unit, click the Lock all parameters icon for that unit.

     If distillation data is available for flowsheet streams, and fitting is enabled during generation, you can see the fitting results in the Distillation graph. See Distillation graph.

7. If required, set constraints on properties

   You can configure individual constraints governing the behaviour of property profiles in the Constraints page.

   

   Two types of constraints on properties are supported in Assay:

   • Global Constraints. Global constraints govern the default behaviour of properties throughout Assay in the absence of any other property constraining information. Global constraints on properties may be set up and managed on a property by property basis using the Property Manager. See Configure Your Properties.

   • Local constraints. Local constraints govern the behaviour of properties within a particular crude assay. They override any corresponding global constraints that would otherwise be applied to the property. However, they apply only to the individual assays in which they reside. Thus, for example, a local constraint specifying a monotonically increasing sulphur profile for a crude will not affect the behaviour of the sulphur profiles of other crudes in the database, although any global constraints on the sulphur profile will. Local constraints provide you with significant additional flexibility and control over property profiles and distributions that would otherwise not be available.

     Local constraints are embedded in the crude assay being worked up, so that they may be remembered within generated crudes, even after they have been saved to the database. However, they are created and managed at the point at which an assay is being worked up within a Generation module.

     You can also activate a number of predefined constraints on multiple properties by selecting the corresponding check boxes in the Multiple Property Constraints pane at the bottom of the page.

     

     The behaviour of local and global constraints when creating a new crude description from within a Generation module is determined as follows:

   • When beginning a new generation from scratch, the default property constraints are applied. In this case the local constraints and global constraints for the properties of the crude will be the same.

   • When copying or importing a crude to a Generation module, constraints are copied across with the crude if these are present in the crude assay. In this case, for these properties, the local constraints may differ from the global constraints.

   • When copying or importing a crude to a Generation module, default property constraints associated with the Property Manager are applied provided no constraints are present in the crude assay. In this case the local and global constraints for the properties of the crude will be the same.

     Note: In addition to constraints, you can also use guide points to have control over individual properties.

     

     To add a constraint for a property, select the property from the Properties pane on the left hand side of the constraints page. Click the Add button to open the Constraint Editor dialog.

     In the constraint dialog, select an effective boiling point range and temperature scale for the constraint. Then select an appropriate type of constraint:

   • Value between: Enter maximum and minimum values to ensure the value for the property remains between the selected range. You can set the units for this range from the associated drop down list.

   • Value fixed at: Enter a value to ensure a fixed value for the property. You can set the units for the fixed value from the associated drop down list.

   • Monotonically: Select increasing or decreasing to ensure the value for the property never decreases or increases, respectively.

     To add the new constraint, click OK. The new constraint is added to the list of constraints for the property given in the Constraints pane.

     To cancel adding the constraint, click Cancel. You are returned to the Constraints information page proper.

     To edit a constraint, either double click on it in the Constraints pane, or select it and click the Edit button at the bottom of the pane. This opens the Constraint Editor dialog box.

     To remove a constraint for a property, select it in the Constraints pane and click the Remove button at the bottom of the pane.

     Once constraints on a property have been configured, they will be applied in all subsequent operations involving the fitting of profiles for that property in the current assay.

8. Generate the crude

   After entering all relevant data into the AssayWorkup module, you can generate the crude at any time by clicking the Generate button in the Assay group of the Home ribbon bar (Generating a crude).

   After entering all the relevant data into the document you can generate the assay by doing either of the following:

   • Click the Generate button in the Assay group of the Home ribbon tab.

   • Press the F5 key.

     After the generation you should look at the Diagnostics page to check for information messages, errors and warnings.

     

     Select an entry from the Type list to show just a subset of diagnostic messages. If you choose Data from this list, additional subcategories become available from the Category box.

     You can also filter the diagnostic messages via the Filter drop-down menu. By default all types of messages (Errors, Warnings and Information) are displayed. Open the Filter menu by clicking on the arrow button, then select or clear the check box next to each message type to show or hide the corresponding messages.

     Click the Configure filters button to open the Filter Configuration dialog, which allows you to define more specific filters. This dialog works in the same way as the Filter Configuration dialog for Database views, but you can only add conditions of type Textual Filter. See Filter types and Textual filter.

     To copy the list of diagnostics to the Clipboard, select the rows you want to copy and click the button. To save the list of diagnostics, click the button. You can export the data as a text file or as a ssf file.

9. If required, additionally edit crude profiles

   Having generated the crude, you can additionally 'fine-tune' the crude description, by editing property profiles. The primary means of editing the crude profiles is via the Profile Graphs and associated information tools. In particular, you can:

   • Control values by moving h-bars on the graph,

   • Control values by using guide points. See Guide Points.

   • Control the smoothness of property profiles on the Profile Graph using the Tension parameter on the Graph Information dialog.

     When editing crude profiles, the usual workflow is to:

   • Change the properties on the graph in turn to each property that needs to be fitted use the Y-axis property selector. See Configure the graph axes.

   • Modify the property as desired, either directly on the graph, from the Graph Information dialog, or in the Measurement Grid. See Edit measurements.

   • Refit the crude to update its property profiles. See Regenerating a crude in User crudes.

10. Use the Crude

    At any point in your workflow, you can save the crude to the Database by clicking the Save button in the Document group of the Home ribbon tab.

    After the crude has been added to the Database, all of the usual functionality of Assay can be used to analyse and study the crude.