Optimizing Lift Operations and Vessel Transport Schedules for Topsides Disassembly of Multiple Offshore Platforms Based on BIM and GIS

An increasing number of offshore platforms across the world will be retired and decommissioned in the coming decade. Since one stakeholder usually needs to decommission multiple offshore platforms simultaneously, topsides... [ view full abstract ]

An increasing number of offshore platforms across the world will be retired and decommissioned in the coming decade. Since one stakeholder usually needs to decommission multiple offshore platforms simultaneously, topsides disassembly, including module lift operations and vessel transport schedule, should be carefully planned with necessary concerns such as offshore safety, cost, and environmental impact. However, the study of topsides disassembly among multiple offshore platforms is still limited. Therefore, this study aims at optimizing offshore lift operations and vessel transport schedule by integrating building information model (BIM) technology and Geographic Information System (GIS). BIM and GIS provide the required information, including module dimension, location on the platform, vessel dimension, and offshore platform spatial data, for the optimization of topsides disassembly activities. As for the module lift operation part, the target is to assign functional modules from platform to the pre-determined locations on the vessel (i.e. module layouts), genetic algorithm (GA) is used to solve this combinational problem. Then, according to the optimized module layouts, the platforms that each vessel requires to visit can be determined. The problem of transport schedule for each vessel can be converted to network or graph search problem to obtain the optimal schedule with least transport time, energy consumption, and cost. To efficiently utilize the proposed solutions for the topsides disassembly among multiple offshore platforms, a BIM/GIS-based web system is developed. The proposed web system contains functions of information extraction from BIM and GIS, module layout optimization, and vessel transport schedule optimization. Finally, an example of three offshore platforms (contains eighteen modules) and two transport vessels is used to illustrate the proposed BIM/GIS-based web system. The results show that the proposed solutions can help plan topsides disassembly among multiple offshore platforms automatically and accurately. Besides, the developed web system can significantly improve the efficiency of topsides disassembly activities.    

Keywords: BIM, GA, GIS, Facility layout problem, Optimization, Vessel transport schedule