The geological features revealed by well production data or 4D Seismic are often neglected in data assimilation or disconnected from the geomodelling tasks through simplifications on static and dynamic data. This work provides a workflow to accurately integrate 4D seismic insights through a forward geomodelling approach and provides prior simulation models calibrated with observed dynamic data. The methodology follows four steps: (1) develop the geological model, (2) generate equiprobable geostatistical realisations based on the multiple stochastic approach, (3) apply the DLHG method (Discretized Latin Hypercube combined with Geostatistics), and (4) validate the geological consistency and uncertainty quantification using the observed dynamic data. The methodology is applied to a real turbiditic reservoir, a heavy oil field in the offshore Campos Basin, Brazil. From the 4D seismic datasets, the following data was available: (1) base survey, (2) monitor-2016, and (3) monitor-2020. The interpreted 4D seismic trends were integrated in the geological model by combining the geometrical modelling technique, for observed structural features, with the objects’ modelling approach, for the observed sand channels. The geostatistical realisations were then combined with dynamic uncertainties through the DLHG method. The quantitative validation based on the NQDS indicator showed that the generated prior simulation models encompass the observed production data. In addition, the match with observed 4D seismic data based on dRMS amplitude maps highlighted the value of adding 4D seismic information. This paper presents a successful forward modelling approach to highlight the value of 4D seismic on the calibration of simulation models prior to data assimilation.