Balancing Efficiency and Safety: Weight Optimization Strategies for FPSO Topsides

Weight optimization is a critical aspect of designing Floating Production Storage and Offloading (FPSO) topsides. Effective strategies not only enhance the structural integrity and safety of the vessel but also improve operational efficiency and cost-effectiveness. This article explores various innovative approaches to weight reduction, including the use of advanced materials and state-of-the-art engineering practices. By implementing these strategies, the industry can achieve significant weight savings, leading to more sustainable and economically viable FPSO operations.

Weight issues are common problem on the design process of FPSO or any other offshore installation. Offshore installations are required to be compact since every tonnage that they have are translated to significant cost in term installation on top of material supply and fabrication. As explain on previous article (Ref to: Balancing the Behemoth: The Crucial Roles of FPSO Weight Control), weight estimation is difficult to be accurate at the early stages and for that reason many projects are experiencing weight increase issues during early stage of detail engineering.

Below are several general actions based on author experience that required as immediate action to weight issues during detail engineering phase,

·?????? Identify and isolating your weight issues. As soon as you identifying the weight problem at the FPSO topside, you need to start to analyze where it the source of the problem. Normally we start we are reviewing disciplines weight ratio per module and compare it with the benchmark or norm. By doing this we can identify and try to isolate the problem to minimize the require changes.

·?????? Reconfirm your main equipment weight and compact equipment selection. Equipment weight always come on the top 5 as the weight issues contributor. Communication with the vendor to narrow down the range of the forecasted equipment weight. In addition, you can select more compact or lighter equipment to select if they can comply with the technical requirements.

·?????? Check your structural standardization and revisit the primary and secondary sizing. In many cases, FEED is applying standardization to minimize the engineering effort before FID. This approach can lead to inefficient sizing selection of the primary and secondary structure. Review on this area shall be perform by structural engineer to optimize the sizing as necessary without jeopardizing the overall structural integrity.

·?????? Tertiary structure optimization. When you have a weight issues, the tertiary structure is one of the subjects that normally optimized. This is covering the review of type of handrail, optimization of lifting beam, removal of unnecessary access platform and optimization of stair tower.

·?????? Review Valves number, type and actuator sizing. In term of piping, in the even of weight issues review of number valves are mandatory for process team. Removal of “nice to have valves” for by-pass, future reservation, maintenance isolation will be deeply review. In addition, selection of reduce bore instead of full bore and utilization of compact actuator are normally pursued to reduce the weight.

·?????? Multidisciplinary support between piping, electrical and instrumentation. Support is always design in silo between multiple disciplines. So, we will end up having dedicated support for each discipline instead having one support for multiple users. To reduce the weight the three disciplines shall sit together and define their joint corridor and applied at maximum the multidisciplinary support.

·?????? Alternative Materials Implementation. As the last resort lighter material which is normally having higher cost are selected. For example: replacing the CS lines with Duplex, Changing Flange connection with Hub, Changing S-300 material to S-400 material, changing the grating material from steel to GRP, etc.

On top of general action above, each project might have its specificity of weight issues resolution based on their characteristic, constraint and environment. Depend on which stage you react; the weight optimization cost magnitude will vary. The earlier you identify the trend of weight increase and applied weight optimization schemes, the lesser of cost magnitude impacted the project. In contrary, if we are late to identify and react, the project will need to either accept the increase of weight plus it’s associated cost or perform a radical change which will delay the project.

In conclusion, weight optimization for FPSO topsides is a multifaceted challenge that requires a blend of innovative materials, advanced engineering techniques, and strategic design approaches. By focusing on reducing weight using at the early stage the industry can achieve significant improvements in efficiency, safety, and cost-effectiveness. These strategies not only enhance the operational performance of FPSOs but also contribute to their sustainability and economic viability. As the demand for offshore oil and gas production continues to grow, the importance of weight optimization in FPSO topsides will remain a critical factor in ensuring the success and longevity of these vital offshore assets