• Closure Law Model Uncertainty Quantification 

      Strand, Andreas; Kjølaas, Jørn; Bergstrøm, Trond Harald; Steinsland, Ingelin; Hellevik, Leif Rune (Peer reviewed; Journal article, 2021)
      The prediction uncertainty in simulators for industrial processes is due to uncertainties in the input variables and uncertainties in specification of the models, in particular the closure laws. In this work, the uncertainty ...
    • Experiments and modelling of three-phase vertical pipe flow 

      Kjølaas, Jørn; Belt, Roel; Wolden, Marita; Schümann, Heiner; Richon, Vanessa (Peer reviewed; Journal article, 2021)
      A set of two- and three-phase experiments were conducted in a 50 m long 400 vertical pipe using nitrogen, Exxsol D60 and water at 45 bara pressure. The results show that the liquid content and pressure drop are highly ...
    • Large scale experiments on high-rate three-phase low liquid loading flows 

      Kjølaas, Jørn; Unander, Tor Erling; Schümann, Heiner; Wolden, Marita; Holm, Henning (International Conference on Multiphase Technology;2019, Chapter; Peer reviewed, 2019)
      A comprehensive three-phase flow campaign, funded by Equinor as part of the Tanzania gas field development project [1] [2] [3], was carried out in the SINTEF Large Scale Loop at Tiller in 2017-2018. The experiments were ...
    • Literature review on surface-active components in emulsions and foams: Theory and modelling efforts 

      Simonsen, Galina; Kjølaas, Jørn; Leinan, Paul Roger; Schümann, Heiner (Peer reviewed; Journal article, 2023)
      In this paper we present a literature review on the role of surface-active components in emulsions and foams. Models are presently unable to accurately predict scenarios involving multiphase flows with complex chemistry, ...
    • Modelling of dispersed oil/water flow in a near-horizontal pipe 

      Kjølaas, Jørn; Schümann, Heiner; Gonzalez Rengifo, Diana Carolina; Johansen, Stein Tore (Peer reviewed; Journal article, 2022)
      A gravity-diffusion model was implemented for predicting water concentration profiles in dispersed oil-continuous oil–water flows. In this model, the measured droplet size distributions were used instead of a droplet size ...
    • Modelling of the wall film in high-rate low liquid loading flows 

      Kjølaas, Jørn; Holm, Henning (International Conference on Multiphase Technology;2019, Chapter; Peer reviewed, 2019)
      In this paper we present a detailed analysis of large scale experimental data from the SINTEF Multiphase Laboratory on high-rate low liquid loading flows. The experimental work [1] was funded by Equinor as part of the ...
    • Onset of water accumulation in oil/water pipe flow – experiments and modelling with LedaFlow 

      Kjølaas, Jørn; Wolden, Marita (Peer reviewed; Journal article, 2020)
      In oil/water flows with very low water rates, the steady-state water fraction jumps discontinuously from a low value to a high value when the oil rate falls below the critical value. This jump is understood to be connected ...
    • Pipe flow experiments of unstable oil-water dispersions with three different oil viscosities: Flow pattern, pressure drop and droplet size measurements 

      Gonzalez Rengifo, Diana Carolina; Schümann, Heiner; Kjølaas, Jørn (Peer reviewed; Journal article, 2022)
      The transport of oil-water dispersions in petroleum production pipelines is difficult to predict and requires special attention since it affects the performance of the entire system. For future field developments it is ...
    • Pseudo slug flow in viscous oil systems – experiments and modelling with LedaFlow 

      Kjølaas, Jørn; Smith, Ivar Eskerud; Brekken, Christian (11th North American Conference on Multiphase Technology;2018, Chapter; Peer reviewed, 2018)
      An experimental two-phase flow campaign with a viscous oil (100 cP) was conducted in the Large Scale 8" loop at the SINTEF Multiphase Flow Laboratory. The loop consisted of three main test sections, with pipe inclinations ...
    • Simulation of two-phase viscous oil flow 

      Johansen, Stein Tore; Mo, Sjur; Kjølaas, Jørn; Brekken, Christian; Smith, Eskerud (SINTEF Proceedings;1, Chapter; Conference object; Peer reviewed, 2015)
      Multiphase flows of heavy oils and other fluids with high apparent viscosity is a particular industrial challenge. Main challenges here is that interfacial waves, atomization at the large scale gas–liquid interface as well ...