Tips & Tricks: Density @ 60 F Curve in Oil Source
Some laboratory analyses include a table of density values at different distillation fractions of a crude oil. If this table is added to a characterization procedure, along with the respective crude oil distillation curve, the density prediction can be significantly improved. The inclusion of these density tables is now possible in the Symmetry process software platform.
The Density @ 60 F curve has been added to the list of laboratory analyses that are available in the Oil Source unit operation from the Symmetry process platform. This new option can be used to add to a characterization the density @ 60 F values at different distillation fractions of a hydrocarbon fluid.
This calculation can be used when a distillation curve is available in the Oil Source; the table data is entered in a specific tab where the densities can be directly matched along with the distillation curve without performing any parameter regression.
Oil Source Density @ 60 F Curve
Entering the Data
The Density @ 60 F Curve option can be accessed in the Laboratory Analyses grid from the Oil Source Summary tab, it is only available if a Distillation Curve with a Direct Calculation Mode is added.
Once the Density @ 60 F option is selected, a new tab Density @ 60 F is brought up. This tab is used to enter the density @ 60 F values for different distillation fractions.
Different options can be selected, including: the curve and Density @ 60 F Basis, number of Curve Points, the inclusion of Density @ 60 F Bulk Value and Direct Match.
The Incl. Bulk value option will bring another frame where the Density @ 60 F bulk value can be specified, and its calculated value will be displayed.
The Direct Match option allows the density curve and bulk value (if specified) to be directly matched without performing any regressions. This procedure is performed by adjusting the PIONA distribution in each internal boiling point group to match the corresponding specified density. Since the PIONA distribution will be fixed in this case, matching other experimental variables will not be possible unless the Direct Match option is disabled.
The direct calculation of the Density @ 60 F curve will not affect the overall result of the corresponding Distillation curve and both will be matched without performing any regression procedure.
Herbert Loria, Ph.D, P.Eng., VMG Calgary
Please contact your local VMG office for more information.