• PVTsim from 20.0 to 21.0

Updates and Bug Fixes

GENERAL

  • Hg added to pure component database.
  • Improved solubility of salt in H2O-MEG solutions.
  • Refined distinction between dew and bubble points for fluid compositions with two critical points.
  • Improved densities from Water Package for pressures of ~ 750 atm - 1000 atm and temperatures below ~ 263.15 K.

FLUID MANAGEMENT


Characterization

  • Input check for valid plus molecular weight changed to accept higher plus molecular weights.
  • Bug corrected in check for acceptable limits of plus molecular weight for compositions with mol%'s/weight%'s to higher carbon number than molecular weights.
  • Use of inconsistent Gas Constants corrected. Will cause slight change in melting enthalpies.
  • Minor error corrected in properties assigned to C89 and heavier when Heavy Oil characterization selected.
  • Cp coefficients and critical pressure for wax components safe guarded against unreasonably high C7+ densities.
  • Logic changed not to show M & C coefficients for lumped components.
  • With PR EOS lumped components erroneously had hydrate parameters shown although not a hydrate former.

Complete

  • Changed to not estimate missing volume correction parameters (Peneloux) for salt components.
  • Peneloux volume correction (Cpen), Cp coefficients and Parachor now estimated for pseudo-components also when actual component has no liquid density assigned.

Delump

  • Delump did not always work with Heavy Oil Characterization.

Mix

  • Logic changed to not have aqueous components influence CSP viscosity correction factors.

QC

  • Standard conditions used for simulations echoed in report.
  • Error corrected in QC evaluation of  plus component amount for compositions of Heavy Oil Fluid Type.

PVT & REGRESSION


Equilibrium Contact Experiment

  • With molar and mass based mixing it is no longer a requirement that the injection gas and the oil to be mixed in an equilibrium contact experiment are single phase at experimental P and T.
  • Simulation was previously always carried out using the EOS the fluid was characterized for no matter which EOS selected.

Depth Gradient

  • Code updated to ensure consistent P and Psat at GOC.
  • Depth gradient option and depth gradient regression option updated to handle a depth interval of 2500 m.

MMP

  • Some tie-line compositions were erroneously displayed as zeros when 3 phases found at MMP.

Multi Contact Experiment

  • Help text updated with correct interpretation of mix ratio for reverse contact.
  • With molar and mass based mixing it is no longer a requirement that the injection gas and the oil to the first stage are single phase at experimental P and T.

Regression

  • Bug corrected in logic for regression on Peneloux volume correction factors for already characterized fluids.
  • C6 density erroneously corrected when match of liquid densities specified for a characterized regression.
  • Safe guard introduced to prevent one phase to be found at pressures just below Psat. That could previously be a problem for near critical fluids.
  • Logic for  regression on kij's updated to ensure kij's not modified  more than max limit.
  • Procedure for keeping Tc and Pc of C7 almost fixed during plus regression updated to work for fluids with molecular weight and density lumped back to C7+.

Slim Tube

  • Pressure range in which miscibility develops is output. Cell number and time step in which miscibility is first seen are also output.
  • Phase Viscosity Mobility added as a transport mechanism.
  • Speed optimized implementation of LBC viscosity model in slim tube option.
  • Numbers on plots were not shown in correct units unless when in metric units.

Swelling

  • Improved procedure for checking whether simulated saturation points are bubble or dew points.

FLASH & UNIT OPERATIONS


Flash

  • VT Flash updated to handle single phase aqueous mixtures.
  • T-beta and P-beta flashes allowed for pure components.

H2S

  • Bug corrected in calculation of HS-/H2S ratio.
  • Incorrect volumetric properties and enthalpy output when volume corrected EOS used and mixture contained components with no volume correction assigned.

Phase Envelope

  • Logic updated to take into consideration Omega A and Omega B values deviating from default.
  • Code updated to better handle binaries of aq, non-aq mixtures.

FLOW ASSURANCE


Asphaltene

    • Improved phase identification criterion implemented.
    • Upper pressure limit for asphaltene PT-curves increased to 10,000 atm.
    • Improved numerical robustness of asphaltene PT curve generation to better handle PC-SAFT EOS simulations.
    • Cv for single phase fluids corrected.
    • Error corrected in calculation of H, S and Cp of gas phases.

When using the <Split Pseudos> option the kij input for pairs a C1-C9 hydrocarbon and an asphaltene component is now also applied for fluids, which have already been split into asphaltene and non-asphaltene components.

DepoWax

  • Correlations used in DepoWax for inner heat transfer coefficient in laminar region have been updated to give a faster and more realistic heat transfer.
  • If only data below WAP were present in a wax viscosity tuning, D, E and F in the model for the viscosity of wax in suspension were not updated in the fluids and the tuned fluids were not saved even if saving was asked for.

OPEN STRUCTURE


Open Structure Flash

  • Incorrect values were returned for some derivatives.
  • Reported composition was incorrect for mixtures with salts when using derivatives.
  • Phase derivatives of density and entropy added for PT non-aqueous, PT aqueous, PH and PS specifications.
  • Derivatives now allowed in combination with water package for PT aqueous flash.
  • Water package now allowed for fluids with inhibitor for PT aqueous flash.
  • Corrected error codes returned for FlashNotAllowed for beta-flashes and K-factor and Split-factor flashes.
  • Flash.FlashOptions = "property generator mode" erroneously now blocked for K-factor and Split-factor flashes. Options did previously not react to the switch.
  • T-beta and P-beta flashes now allowed for pure components.
  • T-beta and P-beta flashes now allowed for beta’s other than 0 and 1.
  • Fugacities for salt components erroneously unit converted as if they were real numbers. Should have remained -1E16 (no value).

Open Structure Hydrate

  • Cv and Kappa erroneously returned for the mixture for Hydrate T, Hydrate P and Minimum Inhibitor options.
  • Fugacities for salt components erroneously unit converted as if they were real numbers. Should have remained -1E16 (no value).

INTERFACE OPTIONS


Eclipse Black Oil

  • Improved method for correcting for non-monotony.
  • Changed to accept non-monotonic saturated Rv's. Lines with non-monotonic undersaturated Rv's deleted.
  • More decimals on GOR and Rv.
  • Output format changed to handle viscosities as high as 1,000,000 cP.
  • Rs vs. depth option in Eclipse Black Oil interface updated to work with K-factors/Split-factors.
  • Output formats updated to handle Rv's>100 STB/MSCF and Bg's > 10,000 RB/MSCF.
  • Input menu updated with notification of non-default standard conditions.
  • Format updated to handle very small or large values of Rs.

Eclipse Black Oil Correlations

  • Minor change in constant in Beggs-Vazquez Oil FVF correlation.

Eclipse Compositional

  • 1st and 2nd CSP coefficient transferred in PEDTUNE keyword for tuned CSP viscosity model.

Eclipse Compositional Import

  • If information about unit system is not found in the imported file, a warning is raised saying that METRIC units are assumed.
  • Updated to handle comment lines between keyword and values.
  • Updated to catch incorrect number of values in a block.
  • Updated to handle more components and compositions.
  • PEDTUNE keyword representing 1st and 2nd CSP coefficient now recognized.
  • Viscosity model defined in imported file now recognized. User alerted if this viscosity model differs from the viscosity model selected in PVTsim.

Hysys

  • Extended with ability to get consistent densities using the PVTsim file reader, i.e. without having to manually set up a GCEOS in Hysys.

More Black Oil

  • Format updated to handle very small or large values of Rs.
  • Input menu updated with notification of non-default standard conditions.

More EOS

  • Updated to support Omega multipliers different from 1.0.

OLGA

  • Phase identification criterion updated to handle near critical fluids correctly.
  • Refined handling of aqueous phase supersaturated with salt.
  • Improved logic for generating artificial gas properties near bubble point.
  • Bug corrected in logic for forcing water density to be for liquid water.

Pipesim

  • Bug corrected in logic for forcing water density to be for liquid water.

Prosper/MBAL

  • Output format modified to show more digits for small numbers.
  • Updated to handle up to 38 pressure steps and 9 temperature steps.

PVTsim Hysys File Reader

  • Error reading Cpen of defined components fixed.

Stars

  • Error corrected in STARS-interface. By mistake EOS was determined by EOS fluid was characterized for and not by user selected EOS.

Vip Black Oil

  • Format updated to handle very small or large values of Rs.
  • Input menu updated with notification of non-default standard conditions.
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