Page 25: of Offshore Engineer Magazine (Mar/Apr 2017)

24 26

This means using the likes of linear performing initial hull sizing, but then diffraction/radiation analysis and sto- verifying the results using traditional chastic post-processing. Using an ANN manual calculations, with positive estimator speeds up the entire process. results. As an example, the ? rm has

Neural networking “In order to speed up this process, produced indicative designs for sister we together with Technip are develop- vessels to the Libra FPSO (an Inocean

MAKE ing an automated iterative algorithm for design), using parts of the ANN algo- sizing of FPSOs,” Kaafjeld says. “This rithm it developed. The image shown algorithm works through numerous depicts how the ANN algorithm works

QUALIFIED by design size combinations and automatically – how the designer can trim the design recalculates the effects on weight, until a desired result is achieved.

DECISIONS stability, motions, etc., by integrated Of course, this is a conservative in- routines.” dustry. Classi? cation societies will not

QUICKLY

ANN is not new. It was ? rst developed allow a design produced this way to be in the 1950s and 1960s, but the use of classi? ed. What the tool can help with is

AND WITH graphics processing units found in high- getting through the initial iterative pro- end graphics cards has helped cess faster, as the optimal hull the creation of so-called Deep size is obtained in a shorter

CONFIDENCE

Nets, enabling computers to amount of time, i.e. potentially beat humans at quite complex helping to reduce costs, and games, such as the complex before starting traditional cal-

READ Cased Hole has been

Chinese board game Go. For culations. The system is also

FPSO design, however, this lev- being continuously developed enabling operators to maximise el of system isn’t necessarily re- and improved.

operating efciency, minimise risk quired, says Espen Engebretsen, “We still believe that we

Espen and intervention costs for over 25 one of the new generation MSc need to do the traditional

Engebretsen years. We are experts in production

Naval Architects (born 1987). hydrodynamic and structural and integrity evaluation; with our

Inocean is drawing TechnipFMC’s hydrostatic calculations for the design,

FIDE (Floater Integrated Design but as time goes by we will be able to in-house ANSA team providing

Environment), a sizing tool that en- integrate this analysis more into our unrivalled downhole analytical ables a trained user to perform sizing of tools,” Kaafjeld says. excellence for all your production spars, semisubmersibles and tension leg A tender could be produced far logging and well integrity platforms (up to scantling level for class faster, with options given, which can be approval). Inocean and TechnipFMC quickly altered according to a chang- evaluation needs have cooperated to include sizing of ing speci? cation – additional risers, ship-shaped FPSOs into FIDE and are bigger tanks, etc. What’s interesting currently working on integrating the for Kaafjeld is that a new generation of

ANN for estimation of hydrodynamic engineers are pushing these techniques, sectional loads. but working alongside more experienced “Within FIDE we have seen a great engineers. advantage of estimating hydrodynamic And hopefully, just as this technology sectional loads without having to utilize is showing its capability in FPSO de- the traditional diffraction/radiation sign, Kaafjeld thinks the FPSO market analysis, which becomes very time con- might be growing again. suming when a large number of size iter- “The market for FPSOs in general ations are evaluated,” Engebretsen says. seems to be growing again,” Kaafjeld “By using [ANN], we have been able says. “A lot of projects seem to be start- to create an estimator, which utilizes ing up again. After the drop in the

Inocean’s vessel database to instantly es- market, we see clients that are more timate hydrodynamic sectional loads.” demanding and more conscious of what

While the tool’s development can they want. They want more optimized take months (with the data it was fed solutions, they want cost-effectiveness carefully selected to provide an ad- and there is the ‘green’ dimension. All equate representative database), and the this is affecting the design of FPSOs.” algorithms built, the training is fast and Just as individual humans are not once it is done, the results are also fast, quite ready to put their lives in the

Engebretsen says. hands of AI, ? oating production systems “Work only took a few months,” he will not yet be fully designed using says. “ANN can be con? gured in mul- ANN. But, AI certainly has a part in tiple ways. What took time was optimiz- making the process faster, reducing the ing it and avoiding some traps.” time and effort required in that other-

Inocean has trialed the system, wise long iterative design process. oedigital.com 026_OE0317_Epic2_Inocean.indd 27 2/21/17 5:56 PM