SEPTEMBER
2014
LNGINDUSTRY
31
O
il and gas production companies are increasingly
turning to natural gas to help meet the growing
demand for energy. However, despite the recent
growth of ‘unconventional’ sources such as shale gas, tight
gas and coal bed methane (CBM), much of the increasing
demand will be met from offshore reserves located in
remote parts of the world, such as the northwest coast of
Australia, the east coast of Africa and the coast of Brazil,
which do not have direct access to the main markets. The
best solution to this problem is now seen as liquefaction at
the point of production.
Major engineering
challenges
Creating the type of floating LNG (FLNG) facilities
that need to be sited above offshore gas fields poses
enormous engineering challenges. Many of the design
issues are similar to those of conventional offshore oil and
gas production platforms, but on a much larger scale.
The design of enclosures, cabinets and shelters for
protecting the instrumentation on FLNG vessels is a case in
point. Depending on the deployment location of the
vessel, they must provide protection against extreme heat
or cold, have a very long service life (40 years or more is
not an unusual design aim) and be able to resist high wind
velocities. They must also be impervious to the extremely
corrosive effects of salt spray and airborne pollutants such
as sour or acid gas, require minimal or ideally no servicing,
and weigh as little as possible.
In the past, environmental protection for relatively
small instruments and associated small-bore pipework on
offshore platforms was often provided by soft insulating
covers, but these degraded very quickly and did not protect
the instruments from corrosive media. Non-fibre-reinforced
plastic enclosures with an integral polyurethane (PU) or
polypropylene (PP) foam liner provided a slightly better
solution, but were vulnerable to impact damage and also
suffered from degradation over time.
Protective enclosures for larger instrumentation
clusters such as process analysers, as well as fire resistant
shelters for vital safety equipment like emergency
