The flow resistance of the existing modules in the bio-ecological drainage system (BIOECODS) is high and may lead to flood instead of its mitigation. As part of efforts to enhance the performance of the system, the river engineering and urban drainage research center (REDAC) module was developed. This study modelled the hydrodynamics of flow through this module using FLOW-3D and laboratory experiments for two cases of free flow without module (FFWM) and flow with a module (FWM) to understand and visualize the effects of the module. With less than 5% error between the numerical and experimental results, REDAC module altered the flow pattern and created resistance by increasing the Manning’s roughness coefficient at the upstream, depth-averaged flow velocity (43.50 cm/s to about 46.50 cm/s) at the downstream and decreasing water depth (7.75–6.50 cm). These variations can be attributed to the complex nature of the module pattern with further increase across the porous openings. Therefore, the technique used herein can be applied to characterize the behavior of fluids in larger arrangments of modules and under different flow conditions without the need for expensive laboratory experiments.

The stability of FPSO or offloading shuttle tanker may be affected in wave conditions which excite parametric rolling. The offloading operations are thereby ceased and eventually leads to loss in production which affects the revenue of global production, better known as downtime cost. This paper discusses downtime cost analysis of offloading operations due to parametric rolling of shuttle tanker under regular waves in Malaysian waters for three different locations. The downtime due to parametric rolling is investigated for two different water depths for which the probability of occurrence was calculated from the location specific wave scatter diagram. The results of parametric rolling of shuttle tanker along with downtime cost charts are presented. Additionally, a Graphical User Interface (GUI) was developed and its work procedure is demonstrated in this paper. The down-time cost calculator will help the oil operator companies to analyze the economic risks involved for field developments and anticipate the loss in revenue for downtime occurrences. The developed GUI was copyrighted under literary work as intellectual property.

A real time motion of moored FPSO in side-by-side configuration for regular wave is simulated in ANSYS AQWA to evaluate the structure motion responses and cable forces under criteria and operational wave conditions for two sea-state. The mooring failure is simulated wherein whole cable tensile forces are calculated. Downtime occurs when the vessel motion and cable responses in operating wave conditions exceed the safe limiting values. With the help of a real time wave scatter diagram of three different locations in Malaysian waters, the probability occurrences are obtained and finally a novel study on the downtime cost analysis for offloading operations is performed considering structure responses and mooring failure conditions. In this paper, a successful attempt has been made to connect vessel motion responses to cost. This paper evaluates the possible downtime cost and economical risks involved in the different locations of Malaysian waters for offloading operations.