Add a new SRPV case

Click the SPRV button in the Managers group of the Reference Data ribbon tab.

Note that two SRPV templates are provided by default:

• LP Sample Model: This SRPV template illustrates a representative case of a generic LP simulation package.

• Sample: This SRPV template illustrates the use of the SRPV Manager.

To add a new template for an SRPV case, click the button on the SRPV Toolbar. To configure the case, you need to:

• Uniquely identify the SRPV case via a case name

• Specify the products comprising the case

• Specify any variations to which each product is subject.

These steps are described below.

1. Choose a case name

   Enter a name for the case and define the base currency and result unit. The Case Name is used to refer to the template in the Case List, and when selected which result to display in the Database.

   

   Enter the name for the Case in the Name textbox, and set the currency and result basis using the Unit menus. The currency can be selected from a list of common units, or selected from the list. The basis for the results should be selected from the drop-down list. Individual fractions can have prices set in different bases, but overall results will be quoted in the Case default basis.

   For example, if the Case has the basis set as $/bbl, then results will be quoted in $/bbl. It is still possible to enter prices in $/tonne, and Assay will convert the price to the appropriate final unit.

   Warning: Although prices can be entered in different mass or volume bases, the currency must always be entered in the same amount. For example, it is possible to enter prices as per barrel, or per tonne. However all prices would have to be quoted in $. It is not possible to enter prices in mixed currencies, or mixed units of currency. For example, it is not possible to enter prices in cents. So for example, if gasoline were priced at 76 cents/gallon, this should be entered as 0.76 $/gallon.

2. Configure Cuts and Pricing

   An SRPV case comprises a number of products. Each product whose value is known should be added to the case in the Cut values pane of the template manager.

   

   Each entry in the Products values list comprises 4 fields, which specify the cut name, a start boiling point, an end boiling point, and a unit base price.

   Field	Description	Example
   Product Name	The name of the product defined by the cut.	Jet
   Start	The start boiling point of the cut.	230
   End	The end boiling point of the cut.	330
   Unit	The temperature unit used to define the cut.	°C
   Base Value	The price value per unit of the product defined by the cut. The base price of the product can be varied by defining property variations for the product in the Property variations costs pane, as described in the step below.	$10

   Tip: To calculate the SRPV, Assay calculates the yield of each cut and the value of that product, and sums the value for all the products. You can enter overlapping cuts in the Products list. In this case, the yield will be double-counted. Assay does not check to make sure the cuts are contiguous, so care should be taken to ensure that entered cut points align correctly.

   To add a new product:

   1. Click the button.

   2. Enter a name for the cut.

   3. Set the cut's cut points by selecting from the list of standard cuts or entering custom cut points.

   4. Select to use either Fixed pricing, or Formula based pricing.

   5. If using Fixed pricing enter fixed price of the product.

   6. If using Formula pricing define the formula.

   7. Click OK to create the product and close the dialog.

      

      Formula Pricing

      To define a product's pricing in terms of a formula:

   8. Click the button for each required variable to define the Formula Inputs.

   9. Define the Formula Inputs.

   10. Write a formula using the Formula Inputs and standard mathematical operators to define the price calculation. See Writing formulae.

       

       Formula Inputs

       To define Formula Inputs:

   11. Enter a tag for the formula, this will be used to refer to the property value in the pricing calculation formula.

   12. Select how the formula value is calculated, either from a recut Cut Value, that is the property value of a product or stream, or as the Price of another product stream, or as a Constant value.

   13. If the Formula Input is defined as a Cut Value select the property that should be recut to obtain the value and the unit for the returned value, and either select the existing stream to obtain the property value for in the Product combobox, or enter a custom or standard cut in the Perfect Cut combo.

   14. If the Formula Input is defined as a Price select the other stream whose price should be used from the combobox.

   15. If the Formula Input is defined as a constant enter the value that should be used in place of the formula variable.

3. Define Value Modifiers

   For each product, you can enter a variation in price, according to various specifications.

   

   Adding a property variation

   To enter a Value Modifier:

   16. Click the button next to the Value Modifiers list.

   17. Choose whether to add the modifier to the currently selected product, or to all products.

   18. Select the property which should cause the variation using the Property list.

   19. Select whether the property should vary over it's maximum or minimum value from the Limit menu.

   20. Enter the Maximum or Minimum amount associated with Limit.

   21. Select whether to Add or Subtract money from the product price.

   22. Enter the value to add or subtract from the price.

   23. Enter the step change in the property that causes a unit of value to be added or subtracted.

   Examples

   Property varying over a maximum amount

   

   To enter a property that varies over a maximum amount, choose the limit as Maximum. For example, if the value of a product varies when its N+2A is greater than 40 then choose Maximum and enter a value of 40. Choose whether the value should be added or subtracted to the price in the Value Impact menu, and enter the value modifier amount and step change for this amount. For example, if the product value increases over 40% N+2A, and increases by 5 $ for every 10% over 40 then enter 0.12 as the modifier and 0.2 as the step change. If the N+2A was 45 the value would be increased by 2.5 $/ton, and if the N+2A was 50 the value would be increased by 5 $/ton.

   Property varying under a minimum amount

   

   To enter a property that varies under a minimum amount, choose the limit as Minimum, then enter the appropriate limit value and value to vary by per change in property. For example, to vary the value of a product if its mercaptan content is less than 10ppm select Minimum and enter the limit as 10ppm. If the value should decrease when the mercaptan is lower than this set Value Impact as Subtract and enter the value per change in mercaptan. For example, if the product value decreases under 10ppm mercaptan, and decreases by 5 $ for every 1ppm under 10ppm, then enter 0.05 as the modifier and 1.00 as the step change. If the mercaptan was 9.5 the value would be decreased by 0.025 $/ton, and if the mercaptan was 8 the value would be decreased by 0.1 $/ton.

   Value Modifiers are edited using the buttons in the Value Modifiers section of the SRPV Manager:

   • - add a new Value Modifier to the Case. You must choose whether to use the Value Modifier for the selected product, or all products.

   • - edits the selected Value Modifier's settings.

   • - removes the selected Value Modifier from the case.

     When adding Value Modifiers to a Case, you can add the Modifier to the currently selected product, or to all products at the same time.

     

     Select OK to update the SRPV Case Manager, and make them available in the Configure Views dialog. See Configure your database views.