As new CO2 European emissions guidelines come into force in 2020, state-of-the-art technology provides a strong economic incentive to ensure implementation. Femke Schaefer reports.
European CO2 emission guidelines require significant reductions to be implemented by 2020. The costs of these sustainability measures are substantial.
As the industries involved have so far failed to demonstrate a strong intrinsic motivation, an additional incentive seems necessary to ensure implementation.
Not all sustainability measures on drilling platforms and FPSOs result in increased costs. New state-of-the-art technology undeniably offers numerous opportunities to generate considerable energy savings in industrial cooling and heating applications. These improvements to drilling platforms and FPSOs also produce economic benefits with an excellent ROI. All that is required is a willingness to use the technology which is already available and which has proven itself in other fields of activity.
Energy saving
FPSOs and platforms require large amounts of energy, often self-generated. The power consumption of the various pieces of equipment on a platform, including the air cooled coolers, is therefore often restricted. Reducing energy demand on a platform may result in a lower power package – a power reduction of up to 2MW, for example. However, this would limit the cooling capacity on a platform or FPSO.
New technologies ensure that no limitation of the cooling capacity is required in order to increase production. Furthermore, a reduction in power consumption is achieved, resulting in the use of smaller power units and thus a reduction in the environmental load due to fewer CO2 emissions.
Size does matter
On an FPSO, reduction in the space occupied by equipment means greater storage capacity and additional space for maintenance and repairs. At present, old oil tankers are converted into FPSOs. As the overall inner dimensions of the tank cannot be altered, it is imperative to reduce the size of the equipment.
However advantages can be achieved, especially in new construction. Smaller process equipment enables the construction of smaller new platforms and FPSOs, generating massive economic benefits.
Weight: Lighter equipment means a reduction in the weight of the supporting constructions of an FPSO or platform and thus the weight of the entire module. On an FPSO, this creates a lower centre of gravity. The Maritime Research Institute Netherlands (MARIN) predicts the behaviour of offshore rigs and underlines the importance of the correct location of the centre of gravity for good performance in stormy weather. Less weight also increases the choice of shipyards with the required crane capacity, meaning more competition and lower investments.
Maintenance: Offshore work is generally regarded as one of the world’s riskiest occupations. During equipment maintenance, there is a real risk to people and the environment as a result of leaks, tools and cramped conditions, for example. Streamlining equipment can improve efficiency, minimise problems and avoid high costs. Less maintenance also reduces the health, safety and environmental risks and the amount of downtime involved for the drilling platform or FPSO.
By applying different technological solutions, important contributions to impressive savings can be made on platforms and FPSOs: a weight reduction of over 60 per cent, a weight reduction in the supporting steel construction, a reduction in plot space and easier maintenance. Considering individual appliances, the heat exchanger is particularly important in this industry with great potential for considerable savings.
For example, we could provide a customer in Australia with a Compact Header Heat Exchanger weighing 19,000 kg compared to the conventional type of 32,000 kg. As each device has its own customised foundation, the supporting steel structure is calculated separately. Some players in the market reward each 1000 kilo weight reduction in the steel support construction with 50,000 dollars.
An FPSO has approximately 50 heat exchangers, 10 to 12 of which are in the category middle to high pressure. The Compact Header is particularly suitable for these heat exchangers. The difference between the conventional and the Compact Header heat exchanger is 13 tonnes: 13 tonnes x 10 heat exchangers = 130,000 kg less weight on board an FPSO! Thus some players in the market are willing to spend an ADDITIONAL 130 tonnes x 50,000 =$ 650,000!
Air cooled coolers
Substantial savings can also be achieved with regard to weight, size, maintenance and energy consumption for other equipment on platforms and FPSOs. Take the air cooled cooler, for example.
The new Whizz-Wheel fan system plays an important role in the high efficiency air cooled cooler. This fan system is based on advanced aerospace technology, provides enhanced heat exchange by increasing air flow and can achieve a plot space reduction of over 30 per cent while potentially reducing energy use by over 50 per cent. This has already been achieved for a client in Mexico where 1st and 2nd stage gas coolers were supplied to extend the Litoral-A platform for Pemex. In this case, the plot space was reduced by 30 per cent while energy consumption was reduced by 22 per cent. Furthermore, the connections/motors and drive/cables were reduced by 45 per cent, which automatically affect the total weight and costs. Finally, less maintenance is required because there are no self-induced fan vibrations and mechanical load limits are not at issue.
Sub-sea coolers
An alternative is available for cooling, however. The sub-sea cooler - in which the oscillating movement of the seawater is used as an active cooling generator - can be used as a substitute for air cooled coolers. Due to the use of high quality materials and a special coating, this cooler is not subject to corrosion. Using this application will save you 100 per cent on your energy consumption and 100 per cent on maintenance. Furthermore, huge weight and size reductions are achieved on platforms and FPSOs.
Savings can be made on other equipment too. Traditionally, different pumps are required on drilling platforms and FPSOs for the following performance variations: low pressure - low flow, high pressure - high flow, extremely high pressure - very high flow. Since the Radiax pump is capable of the entire performance range, it can replace hundreds of pumps. Where a conventional centrifugal pump needs five stages in series, a single-stage Radiax (1 x 6-in) is sufficient. The Radiax can be used for these wide-ranging performance variations because the efficiency of a conventional pump falls once it is used outside its operating point. On the other hand, the efficiency of the Radiax pump remains high within the entire operating area. Radiax: unique, programmable menu-driven performance based on the advanced performance curves. The Radiax pump can reduce energy consumption by up to 45%, the weight up to 80 per cent and the size by as much as 95 per cent!
Summary
The use of innovative equipment, which is available and which has proved itself in other fields of activity can achieve substantial savings in the cooling and heating of industrial applications: savings in weight and the corresponding reduction in size of the equipment, improved ease and safety of maintenance and a reduction in energy consumption.
There is still time to apply these solutions before 2020 and indeed, government can play a stimulating role based on the principle: apply the best technology available. Sustainability is high on everybody's agenda. The various economic motives have been demonstrated here, but above all, there’s money to be earned, especially in operational terms.
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Femke Schaefer is with Bronswerk Heat Transfer BV, Nijkerk, The Netherlands. www.bronswerk.nl