“…On the other hand, due to the slow dynamics of the reservoir, steady-state reservoir conditions for a certain time interval can often be assumed (Shippen, 2012). Furthermore, considering the inherent complex multiphase flow characteristics, which make it challenging to develop and solve nonstationary VFMs, steadystate VFMs are the most common approach in literature (Bikmukhametov and Jäschke, 2019), both for physics-based models (Shippen, 2012;Varyan et al, 2015) and machine learning (ML) models (AL-Qutami et al, 2017a,b,c, 2018Bikmukhametov and Jäschke, 2020;Grimstad et al, 2021). Nevertheless, studies show that steady-state VFM models should be updated or recalibrated in time to provide adequate long-term prediction accuracy (Sandnes et al, 2021;Hotvedt et al, 2022).…”