The transient dynamic model approach is carried out on the section x pipe flow to see the type of flow regime in one pipe system. In the simulation process, the duration of simulation time is identified based on the heat transfer parameters in the pipe and its effect on the fluid in the pipe to provide stable simulation results. The flow results are grouped to see the flow behavior in the flow regime map. The investigation process of severe slugging from the base riser to the top riser is reviewed from the formation of slug flow or ID number three from the simulation results. The severe slugging problem that occurs is solved by parametric study for choke opening for topside choke, gas mass flow rate for gas lift, and the combination of both. The duration required to achieve stable simulation results on pipeline section x is 90 days. There are four types of flow regime formed from the grouping, including stratified, annular, slug and bubble flow. Slug flow is between the lower range of stratified flow and the upper range of bubble flow with a slight appearance of annular flow. Severe slugging occurred in the pipe section x along the base riser towards the end of the riser. The most effective solution to this problem was the use of 0.8 topside choke opening and 5 kg/s or 0.023 mmscf/d gas mass flow rate at the gas lift. This study provides an integrated explanation in multiphase flow simulation in handling severe slugging in subsea pipeline section x divided into four cases. Early mitigation maps and variations of solution implementation for the severe slugging problem along the base riser to the top riser are provided.