Support needed for process plant development, integration
The emergence of floating liquefied natural gas (FLNG) facili- ties such as Shell’s Prelude and Petronas’ Satu, and Chevron’s Gorgon project offshore Western Australia have greatly in- creased the availability of LNG in the Asia/Pacific region. As more large-scale LNG projects come on stream the nature of
gas as a primary fuel is also changing, both for the developed world
and developing economies. Expansion of the gas market is also set to
drive down technology costs associated with LNG schemes, thereby
opening up gas as a fuel to an even wider market.
With this greater availability, the trading nature of gas too has begun
to change. While gas prices have historically tended to be more local-
ized and more dependent on fixed long-term sales contracts than oil,
there has been a move of late to a more active spot market, often at
considerable discounts to long-term contract pricing. This has been
facilitated by increased transportability of LNG due to the growth of
the LNG carrier fleet and receiving facilities.
The current lower gas price environment is likely to continue,
• A push for cheaper, simpler, field development solutions on the
upstream (FLNG) side.
• Increased demand for supply-side FSRU (floating storage and
regasification unit) solutions. These are on the upside of a lower
gas price and provide a practical solution to the growing energy
– particularly electricity – demands of developing nations, or anywhere where extended electricity grid networks are impractical.
• Renewed interest in gas compression projects.
There are inevitable knock-on effects on the types and designs
of assets favored for production or supply of gas from LNG, with
attendant pressures on class societies to deliver rules and guidance
for the new offshore vessel designs.
A land-based LNG plant fuelled from a very large floating platform
would require high-volume gas reser ves to justify the high field devel-
opment capex. FLNG vessels are smaller, simpler assets which can be
mobilized more quickly to smaller fields, allowing swift monetization of
projects on a smaller scale. Among the options for FLNG vessels are:
• A simpler liquefaction process allowing a smaller footprint, but
at reduced efficiency.
• More complex, miniaturized liquefaction plant offering smaller
footprint but better efficiency.
• Numerous (more traditional) gas floating production storage and
offloading (FPSO) units providing gas conditioning linked with
a centralized liquefaction facility – allowing individual units to be
smaller and less complex, and potentially reducing the need for
more extensive subsea infrastructure.
• FLNG providing solely liquefaction facilities for gas produced and
conditioned elsewhere and accessed via land or subsea pipeline.
This can bring advantages over land-based solutions for remote
areas, and in regions with dif ficult political or social circumstances.
• Near-shore export FLNG, ranging from simple LNG storage and
offloading to full blown FLNG solutions.
All of these options are under review or are being actively developed
in response to local needs and circumstances.
Gas compression FPSOs
Due to the continuing need to drive down cost, the industry is seeking
innovative solutions to monetize large and small remote offshore gas
accumulations. Proposals are under consideration for:
• Very large offshore floating gas compression projects, the up-
side being the ability to eliminate the need for onboard storage
Non-prescriptive class guidance the way
forward for offshore LNG vessels
The Prelude FLNG vessel under
tow to the field location in the
Browse basin. (Courtesy Shell)