New Features

Version 4.0

Models

Descriptions and references detailing the models are provided in the User Guide for Models and Physical Properties.

Super TRAPP Viscosity Model

The Super TRAPP viscosity model is an extended corresponding states model that uses propane as a reference fluid. This model generally offers improved predictions compared to the previously available models.

Activity Models: Poynting Correction

The way that the Poynting correction is evaluated for activity models at supercritical temperatures has been change to avoid unphysical values of heat capacities.

CSMA model

Four new components have been added to the CSMA model: RR227EA, 1-butene, cis-2-butene and trans-2-butene.

A new generalised equation of state has been added for handling petroleum fractions and other components not previously included in the model.

The mixing rules for the model have been extended. There is the choice of using an enhanced one-fluid mixing rule or the GERG mixing model (see below).

GERG-2004 model

The GERG-2004 model for natural gas and other mixtures has been added. The model is described in the GERG Technical Monograph 15-2007 by O. Kunz et al.. The natural gas components considered in the GERG model are: methane N2, CO2, ethane, propane, n-butane, iso-butane, n-pentane, iso-pentane, n-hexane, n-heptane, n-octane, H2, O2, CO, water, Helium and Argon. The model has been extended to work with other components and petroleum fractions.

PC-SAFT model

The model now includes the results of recent theoretical developments to describe electrostatic interactions. New contributions account for dipolar and quadrupolar interactions.

New BIPs

The binary interaction parameters for H2S, CO2, methane, ethane, propane and water have been revised to improve the VLE predictions for the cubic equations of state, CSMA, LKP and SAFT models. For the CPA model, the CO2-water and H2S-water association parameters were also improved.

Petroleum Fluid Characterisation and Matching

Delumping Characterised Fluids

The delumping method expands the description of a fluid in which petroleum fraction pseudocomponents are present. Each pseudocomponent is delumped into constituent single carbon number fractions. The delumped fluid can be loaded into the Multiflash PVT Analysis tool allowing it to be re-characterised to give an alternative set of pseudocomponents. This is particularly useful when fluids from other software packages are imported to Multiflash and the user wishes to specify a different characterisation for that fluid.

Viscosity

The correlation for the liquid viscosity of petroleum fractions has been improved for heavy components with a boiling point above 570 K.

Databanks

DIPPR

The latest version of DIPPR available is 2010. There are now 2013 components in the databank. Information on new and revised components is available on request.

Infodata

The number of components in Infodata has increased to 248. Those added for Multiflash 4.0 are: R227EA; Sulphur-2.

New properties: the polarisability and quadrupole moment properties have been added. These properties are not currently set for most components.

The following property values have been revised.

Sulphur-8: all properties.

TEG: liquid density.

Windows GUI

Software framework

The GUI has been upgraded to use the Microsoft .Net framework. The design is substantially the same as in previous versions but some details of appearance and behaviour will be different.

Model selection

The default viscosity model for use with equations of state has been changed from Pedersen to SuperTRAPP.

A new tab with the title CSMA has been added to the model selection window. This tab groups together all the model variants based on the multi-reference fluid corresponding states model including the new GERG-2004 model.

A user-defined BIP databank may be included as part of the model definition.

Delumping Characterised Fluids

The delumping facility can be accessed from the Tools menu or the toolbar button.

Phase Envelope Window

The phase envelope plot displays the coordinates corresponding to the position of the mouse cursor. You can zoom-in on a region by dragging with the left mouse button.

Closing Windows

Most windows can be closed by pressing the key.

Checking for Updates

The Help menu include an option to check for updates to Multiflash.

Licensing

RLM

The Reprise License Manager (RLM) from Reprise Software is now the standard license control system for Multiflash. The Sentinel dongles from SafeNet Inc. will continue to be supported.

Version 3.9

Models

Super TRAPP Thermal conductivity model

The Super TRAPP thermal conductivity model has been added. This is an extended corresponding states model that uses propane as a reference fluid. The model offers improved predictions compared to the existing CLS model, particularly for petroleum fluids.

Linear Gradient Theory surface tension model

The Linear Gradient Theory model may be used to calculate vapour-liquid or liquid-liquid interfacial tension. Predictions are based on the density gradient that exists across the interface. The model works in conjunction with any of the cubic equations of state or the SAFT equation. It may be used to model the interfacial tension between gas-oil, gas-water and oil-water.

CSMA model

Thirteen new components have been added to the CSMA model. These are Carbonyl Sulphide, Ethanol, Cyclohexane, iso-hexane, Krypton, Nitrogen Trifluoride, neo-pentane, Sulphur Dioxide, SF6, Toluene, R141b, R142b and R41. A new model for propane by Lemmon and Span has also been added.

Electrolyte model

The model has been to improve performance when there is an appreciable solubility of hydrocarbons in the aqueous phase. Some small differences between versions 3.8 and 3.9 may be noticed.

New BIPs

The binary interaction parameters for H2S, CO2, methane, ethane, propane and water have been revised to improve the VLE predictions for the cubic equations of state, CSMA, LKP and SAFT models. For the CPA model, the CO2-water and H2S-water

association parameters were also improved.

Matching

Bubble point, GOR and water cut

The procedure for simultaneously matching a GOR and bubble points has been extended to include the specification of the amount of water. The GOR and water cut may be matched even if no bubble point data are available.

Viscosity

A new option to match the viscosity of the stock tank oil composition has been added.

Databanks

DIPPR

The latest version of DIPPR available is 2009. There are now 1973 components in the databank. A list of the additional components is available on request.

Infodata

The number of components in Infodata has increased to 247. Those added for Multiflash 3.9 are:

R227EA

The following property values have been revised:

Methane: surface tension correlation.

Saturated liquid thermal conductivity correlation: butane, pentane, neo-pentane, iso-pentane, hexane, cyclohexane, heptane, octane, nonane, benzene, toluene, methanol, ethanol,

H2S: critical parameters, acentric factor, boiling point, vapour pressure, liquid density, latent heat, perfect gas Cp, surface tension.

CO2: triple point parameters, liquid density, latent heat.

Windows GUI

Model selection

The model selection dialogue has new methods for selecting transport property models. The default thermal conductivity model has been changed from CLS to Super TRAPP. The default surface tension model for most cases has been changed from MCS to Linear Gradient Theory.

Drag and drop for .mfl files

.mfl files can be opened by using drag and drop on the Multiflash GUI window from Windows Explorer.

Current opened file

The GUI now keeps track of the currently opened file. Its complete path is shown on the window title bar. Menu items “Save Problem” and “Save Problem As…” are available allowing the user to save the current file immediately.

Component selection

Multiple components can be selected for deletion.

Log file

The ten most recent log files are kept. The naming sequence is mflash.log; mflash_1.log etc.

Excel Interface

Error state information

If the Excel Add-in fails to load, more information is provided to the user in MF39 so that the relevant actions can be taken to solve the problem.

New flash function arguments

A new surface tension model is implemented in Multiflash 3.9. This model is a true two phase model, so a second phase has to be supplied to the flash functions in Excel.

Multiflash DLL Location

Starting with Multiflash 3.9, the Excel add-in will search automatically for the DLL. This avoids extra installation steps when running the add-in. Now the addin will not crash if the Multiflash DLL is not found.

Deprecated functions

The functions MF_PVT_ANAL and MF_PVT_CNAM were removed as they only worked with the original PVT analysis method, which is no longer available in Multiflash 3.9.

The function MF_MATCH was also removed as it provided only limited functionality to match functions. The GUI should now be used for all match functions.

Property Tables

Prosper

A PVT table file can be generated for the Petroleum Expers Prosper program. For the details, see “Prosper PVT files” on page 39.

Pipesim and OLGA

A “Clear” button has also been added to the Pipesim and OLGA PVT table option to clear all previous entries in the table if necessary.

Obsolete features

Characterisation method 1

The original PVT characterisation method (PVTANAL1) has been removed. It is superceeded by the revised method, PVTANAL2.

Multisolid wax model

The Multisolid wax model has bee removed. It is superceeded by the Coutinho wax model.

Version 3.8

Models

CSMA model

Two new components have been added to the CSMA model. These are R245fa and R143a. The model for H2S has been improved.

Electrolyte model

In MF 3.8 the electrolyte model has been extended to handle halide scales. The equivalent ions supported by MF38 are now Na+, K+, Ca++, Cl- and Br-. An additional option has been added so that you can specify the brine in terms of equivalent Na+ and Cl- only. This effectively reduces the new electrolyte model to the original electrolyte model.

LK model

In MF 3.8, the LK model is available. The LK and LKP methods are 3 parameter corresponding states methods based on interpolating the reduced properties of a mixture between those of two reference substances, see “Lee-Kesler (LK) and Lee-Kesler-Plöcker (LKP) equations of state” on page 32.

Peng-Robinson 1978 (PR78) equation of state

The 1978 revised version of the Peng-Robinson equation is available in MF 3.8. The model has a different treatment for the a parameter. This model removes a defect in the original equation where heavy components with higher acentric factors become more volatile than components with somewhat lower acentric factors. For more information see “Peng-Robinson 1978 (PR78) equation of state” on page 29.

PSRK-NRTL equation of state

PSRK-NRTL equation of state is the same as the PSRK model except that the excess Gibbs energy is provided by the NRTL equation. So unlike the PSRK equation, the PSRK-NRTL variant requires that BIPs are provided for the NRTL equation in order to give accurate results. Its advantage is that, provided the BIPs are fitted to relevant phase-equilibrium data, the model can give more accurate predictions than the PSRK equation.

Thermal properties for activity models

The enthalpy, entropy and heat capacity values calculated by liquid phase activity models are different from previous versions. This is because the contribution of the Poynting correction (pressure correction) to the thermal properties has been revised. The difference in properties is small but noticeable.

Model preferences

In MF 3.8 an option is available for defining preferred models under Preferences. This allows you to set up the same models for all the calculations beforehand. After setting it up, the same models are defined automatically whenever Multiflash is launched again.

Salt calculator

The salt calculator form for the electrolyte model has been extended in MF38 so that the salt/ion analysis data can be converted into the equivalent ions such as Na+, K+, Ca++, Cl- and Br- or Na+ and Cl- only.

Fluid characterisation

D86 and TBP characterisation

New options have been introduced to enable fluids to be characterised using either TBP or ASTM D86 distillation data.

Volume Blending

The volume blending option has been added to the blending facility in MF38 and the associated form modified to incorporate this. Please note that volume blending requires the input of the blending conditions such as temperature and pressure or the density of the blended mixture.

User specified Cuts for pseudocomponents

In previous version of Multiflash, the distribution of the pseudo components was determined automatically. In MF38 there is an option to allow the boundaries of the pseudo components (as carbon numbers) to be specified by the user.

Matching

Water component ignored in matching

The water component is now ignored for bubblepoint, dewpoint, viscosity, wax and asphaltene matching in MF38 if the amount of water is not zero.

Matching viscosity data

The plotting of viscosity data on matching has been modified to improve the plotting range.

Databanks

DIPPR

The latest version of DIPPR available is 2008. There are now 1944 components in the databank. A list of the additional components is available on request.

Infodata

The number of components in Infodata has increased to 246. Those added for Multiflash 3.8 are:

Br-

R1243B

1-nonene

Chemical equilibrium

The chemical equilibrium flash calculations have been removed from the Multiflash 3.8 GUI. If you still require these flash calculations, the previous version of Multiflash, e.g. MF37, should be used

GUI

Toolbar button

The chemical equilibrium button has been removed as these flash calculations are no longer supported in MF38.

Preferences

The “Preferences” option in Multiflash has been expanded to include “General” and “Models” in MF38. “General” supports those preferences available in earlier versions while “Model” is used for defining your preferred models.

Select components

A Clear button has been added to clear the text boxes that have previously been used to define a single petroleum fraction from ‘Infochem Petroleum Correlations’.

Tables

Pipesim and OLGA tables

A “Clear” button has also been added to the Pipesim and OLGA PVT table option to clear all previous entries in the table if necessary.

CAPE-OPEN interface

The CAPE-OPEN interface has been rewritten to improve efficiency and to add new facilities.

Support for Persistence and Editing of Property Packages has been added. All software components are now provided in a single dll. Support for new constant properties and mixture properties and derivatives has also been added.