Page 22 - Impiantistica Industriale

TRANSPORT INFRASTRUCTURE

“Politecnico di Milano”, Department of Chemistry,
Materials, Chemical Engineering “G. Natta”, in Italy.
Therefore, the same department has been involved
in 2021 to adapt the model for different type of flu-
ids like CO and Hydrogen.
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In addition to POLPLUME upgrade works, Saipem
Team developed an internal computational fluid
dynamic model to assess the subsea behavior of
underwater plume for the most complex scenarios
of a CO release (gas and dense phase at various
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water depths).
In summary, the assessment of the consequences
of subsea releases can be carried out with an ap-
proach based on integral models for simple cases
of subsea loss of containment events or adopting a
computational fluid dynamic model for more com-
plex cases. The integral models present the advan-
tage to be fast and suitable for risk assessment of
relatively simple cases. The CFD models are useful
for complex analysis but present the disadvantage
of being time consuming, have high computational
Picture 9 – CFD Plume from a subsea pipeline rupture transporting CO at high pressure cost and they need the specific knowledge of CFD
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in dense phase specialists.
The next step is the validation of these models with
measures where necessary. The risk assessment relevant mid or full-scale experiments on subsea
main steps have been analyzed by Saipem Team to releases of CO or H that do not exist at the mo-
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identify the gaps with respect to H /CO transport. ment. Therefore, Saipem joined safe C02 JIP with
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One gap is in the identification of hazards and thre- major oil and gas companies led by SINTEF to vali-
ats of the frequencies of loss of containment events date those models based on full-scale tests.
and consists in the poor or totally missing data The full-scale experiments are planned in the next
about offshore CO and H Pipelines. The other is years, and they will be executed at sea and at va-
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related to the consequences of loss of containment rious water depths.
events and in particular the lack of a good number In conclusion, Saipem has developed a methodo-
of validation mid or full-scale experimental tests for logy and a path to efficiently carry out Quantitati-
the simulations model of ruptures and underwater ve Risk Assessment for CO and H /NG offshore
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gas dispersion. pipeline systems reducing the uncertainty of the
To estimate the frequencies of loss of containment analysis.
events Saipem developed its own methodology.
It is valid for all type of steel pipelines, flexible li-
nes, risers, and it includes the onshore pipeline
connecting sections. The methodology foresees Final Considerations
to estimate the loss of containment frequencies and Way Forward: the value
starting from the database of release frequencies
for other hydrocarbon pipelines. It foresees that a of R&D in the Industrial
team of representative leaders and specialists of Energy Transition
each project discipline (e.g. corrosion, material se-
lection, pipeline design, flow assurance, safety) is The energy transition requires that offshore pipeli-
involved in a brainstorming workshop. The purpose ne transport is economically convenient and able
of the workshop is to evaluate the threats related to provide large capacity and long-distance tran-
to CO or H transportation for the specific project sport at highest HSE standards. The intersection of
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under analysis and to associate a specific penalty technological gaps and needs allowed the identifi-
factor to the loss of containment frequency coming cation of the values that an R&D effort could bring.
from the hydrocarbon database. The evaluation of Therefore, starting from mechanical design, the ef-
penalty factors is based on the severity of conse- fort has been and will be:
quences of each threat. 1. on standardization, construction, welding and
Once the frequencies of occurrence of CO or H installation methods;
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loss of containment are evaluated, then the conse- 2. for Material Technologies on studies and tests
quences of each loss of containment event need to on materials. This includes development of
be evaluated. The assessment of the consequen- methodology and predictive models for Struc-
ces is usually carried out by means of advanced tural Integrity and Running Shear Fracture,
simulation tools. cooperation within JIPH2Pipe, EPRG and with
Saipem owns an integral model, called POLPLUME other research entities for the experimental ac-
for the simulation of subsea hydrocarbon releases. tivities;
It was developed, in the past, in cooperation with 3. for Safety, on how to assess the frequencies

18 Impiantistica Italiana - Maggio-Giugno 2023