Waller Marine has supported its offshore oil & gas industry clients in many ways since
the Company's inception. The different facets of the industry require different expertise
in the design and construction of vessels and facilities that serve them; offshore
drilling, production, construction, sub sea systems and pipelines, gas-to-liquids and
transportation; Waller Marine has served them all in the past and continues to provide
design, technical assistance and construction services to it's clients worldwide.
The integration of a new methanol process technology with a marine vessel permits
the conversion of large quantities of remote or stranded gas to a liquid for transport to
markets for use as fuel for power generation or feedstock for the petrochemical
industry in the conversion of methanol to olefins (MTO).
The facility is based upon the Starchem methanol process that utilizes enriched air
extracted from the compressor side of a gas turbine to produce synthesis gas in an
auto thermal reformer. This technology eliminates the need for an oxygen plant and
permits much larger methanol production capacities than prior world scale plants, thus
reducing overall capital cost and methanol product competitive with other forms of
energy.
10,000 M.T. Per Day Capacity
The methanol plantship comprises a double hull structure of 1,000 ft in length by 200 ft beam, with storage capacity of 250,000 tons of
methanol product. The process plant is supported on the process deck, similarly to a traditional FPSO. Moored by an extended turret, gas is
supplied through a riser and swivel at rates up to 400 mmscf/d.
The barge is designed with high motion suppression features, constant draft and has the ability to change it's vertical center of gravity by
moving ballast in order to moadify it's natural frequency for motion reduction. Designed for worldwide operations, the facility can accept
wellhead and dry gas, producing either fuel or AA grade methanol for shipment. Product is stored in sufficient quantities to load out 200,000
dwt tankers for transport to either the power generation or MTO chemical markets.
Floating Gas to Liquids Plant
The floating offshore power generation facility was initially conceived
as a means of monetizing stranded offshore natural gas, while
simultaneously permitting offshore oil production in the deep waters of
the Gulf of Mexico. Interest is now being shown by Independent Power
Producers (IPPs) to generate electrical power offshore in order to
reduce the need for lengthy permitting applications needed for land
based power plants.
The facility comprises a combined cycle generating plant using eight
GE LM 6000 gas turbines producing a total of 380 MW, each with a
heat recovery steam generator (HRSG) to raise steam to power a 120
MW steam turbine generator, providing a total capacity of the plant at
500 MW. Gas is supplied either directly from the wellhead or from an
FPSO and delivered to the semi-submersible facility for treatment and
compression prior to entering the turbines.
Electrical power is generated at 13,800 volts, 60 hz, 3 phase and raised to 230 Kv by step-up transformers. To reduce line losses and
cost of transmission the AC power is converted to DC power through a high voltage direct current ABB, (HVDC) rectifier. Two 250 MW
capacity DC transmission lines carry the power ashore to a land based HVDC inverter, where it is converted back to AC for connection
with the grid.
A permanently moored semi-submersible platform with
dimensions of 300 ft. by 200 ft. supports the power plant and its
associated equipment. Design considers hurricane storm
conditions and temporary loss of gas supply with diesel storage
to maintain generation availability. Consideration is given to
reducing pollution by installing selective catalytic reduction (SCR)
units to reduce NOX on the HRSGs. The power plant may be
operated similarly to any land based combined cycle generating
facility, with onboard operators performing similar functions. The
multiple turbines, gas compressors and transformers built into
the design provide a high degree of redundancy.
500 MW Floating Offshore Power generation Facility