All posts by Michal Tóth

New Release 2026.04

We can now announce the release of the 2026.04 version of OPM Flow. Binary packages are available in OPM’s PPA (personal package archives), ppa:opm/ppa. If you have not already enabled this PPA in your package sources you can do so through the following three commands:

sudo apt-add-repository ppa:opm/ppa
sudo apt install libopm-simulators-bin

Please check our installation instructions for more details. Optional packages for MPI and Python bindings are highly recommended.

The 2026.04 OPM Flow release supports the following two Ubuntu LTS versions

  • 24.04 LTS (codename Noble Numbat)
  • 26.04 LTS (codename Resolute Racoon)

Binary packages are also available for RHEL 8. Python packages (linux amd64 and macOS arm64) can be installed via

pip install opm

and, finally, Dockerhub holds amd64, arm64, and NVidia and AMD GPU images.

If you wish to build the release manually on your own system you can check out the release/2026.04 branch or tag release/2026.04/final.

This release brings many contributions, improvements, and fixes. The preliminary release notes are provided in each repository:

OPM Common 2026.04 Release Notes
OPM Grid 2026.04 Release Notes
OPM Simulators 2026.04 Release Notes

This release’s highlights are:

  • Added the option to solve the energy equations sequentially after the black-oil equations.
  • Support has been added for pressure and temperature dependent water viscosity for runs with brine (BRINE) and energy (THERMAL).
  • Flow now supports runs with brine (BRINE) and energy (THERMAL).
  • Added support for double precision WORK arrays for compressed property arrays (for example SOGCR).
  • If necessary, the gas PVT tables PVTG and PVDG are modified internally to ensure that negative inverse formation volume factors will never be extrapolated.
  • Implemented endpoint scaling for gas-water systems.
  • Killough’s hysteresis wetting phase modification (EHYSTR keyword item 13) is now supported.
  • Added support for RSCONST keyword to define a constant solution gas-oil ratio for all dead oil PVT tables.
  • Added support for EQUIL keyword item 9 (EQLOPT3) greater than zero.
  • Added support for well energy injection/production rate and total summary vectors: WTPRHEA, WTPTHEA, WTIRHEA and WTITHEA.
  • Support has been added for the gas lift injection total summary vectors: FGLIT, GGLIT, and WGLIT.
  • Extended summary (ESMRY) files are now output by default. The command line option –enable-esmry is now set to true by default.
  • Added support for region oil recovery efficiency summary vector ROE.
  • Production and gas lift supply rates from satellite groups (GSATPROD) are now accumulated in summary output.
  • Added support for inter-block flows of oil, water, and gas in the negative i, j, and k directions (BFLO[GOW][IJK]-).
  • Added support for summary output of inter-block oil, water, and gas velocities in the positive/negative i, j, and k directions (BVEL[GOW][IJK][-]).
  • All current well lists are now reported to the Print (PRT) file when the WELSPECS mnemonic is specified on the RPTSCHED keyword.
  • Support for using the WDFAC and BRANPROP keywords in an ACTIONX block has been successfully tested.
  • The grid independent well keywords WELTRAJ and COMPTRAJ now partially support multi-segment wells.
  • Added support for using well completion quantities in ACTIONX Boolean conditions.
  • Added partial support for the TUNINGDP keyword.
  • Added support for VFPPROD tables with only one data record (single-line lift curves).
  • The default value for the NUPCOL keyword has been reduced to from 12 to 3.
  • Drift compensation is now applied to mass losses in the energy equations when using the temperature model (TEMP).

More comprehensive list will be published in the reference manual soon. The list is already on github in opm-reference-manual/parts/appendices/B.fodt. Unfortunately, the raw file (as displayed on github) is not designed to be read.

Thank you, again, to all who contributed to this release. Users who reported issues, developers who added new features, improved performance, and provided fixes to issues. I would like to thank Markus Blatt and Arne Morten Kvarving for helping me manage the release and for building the binary packages.

Best Regards,

Michal Tóth
Dr. Blatt – HPC Simulation Software & Services

OPM 2026.04 Release Manager