Environmental Statement - Maersk Oil

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Table 2‐16 The GPIII’s utility systems.
Utility System Description
Balloch Field Development Environmental Statement
Section 2 Proposed Development
Power generation Two main generators (Alstom GT35), driven by dual fuel turbines (fuel gas or diesel)
provide a total of approximately 32 MW.
Four diesel generators each provide 4.2 MW.
One emergency diesel generator rated at 1.7MW, 440v, 60Hz.
Fuel gas The Fuel gas system is designed for 25 mmscfd and fuel gas is preferentially taken
from downstream of the dehydration package.
Flare system The HP Flare system is designed for 155 mmscfd with a minimum design temperature
of –100°C.
The LP Flare system is designed for 25 mmscfd with a minimum design temperature of
–10°C.
Heating Medium Heating medium is distributed to both the inlet and second stage heaters in the
Separation package.
There are two Waste Heat Recovery Units (WHRU), each designed to recover 15 MW
of heat from the power generation exhaust gases.
Chemical Injection The chemical injection package contains fourteen storage tanks and twenty‐two
injection pumps. Swivel flowpaths are also provided for chemical injection.
Seawater cooling Seawater cooling is provided to both the marine systems and topside users. The
process cooling seawater system has a capacity of 1,866 m 3 /hr.
Stream system Steam is produced in 2 x 100 % boilers, each capable of producing 10 tons/hr of steam
at 8 barg. The steam is generated using dual fuel boilers and is supplied for heating to
the cargo heaters, slop tank heaters, fresh water generation, lube oil tank/purifier
heating, bilge holding tank heating, sea chests and hot water systems.
Instrument & Plant Air Both instrument and plant air are supplied from the marine systems. 4 x 33 %
compressors operate, each capable of delivering 1m170 Nm 3 /hr.
2.6.7. POWER DEMAND
On the GPIII the power demand for water injection and gas compression is high, in addition to
variable demands from the FPSO thrusters and during offloading. The demand is satisfied by a
combination of two 16 MW turbine generators and four 4.2 MW generators. Three of the 4.2 MW
generators are dual fuel. Excluding periods of bad weather and cargo offload, the turbine generators
are each nominally rated at 50 % of the total load.
In addition to power generation, there is a 30 MW waste heat recovery system for process heating as
well as other standard utility systems including emergency flare, fuel gas, chemical injection and
drains systems. Waste heat recovery units (WHRUs) have been fitted to both turbines and again,
each rated for 50 % of the peak heat duty. The heating medium is pressurised fresh water.
Existing power generation facilities are expected to be sufficient to meet the power requirements of
the proposed Balloch development. Fuel consumption on the GPIII in 2011 included 16,208 te of
diesel and 27,578 te of gas. This fuel use was associated with the production shown in Table 2‐17.
Production on the GPIII in
2011
Table 2‐17 Total GPIII production in 2011.
Oil (m 3 ) Gas (m 3 ) Produced water (m 3 )
1,155,354 101,331,614 3,947,973
It should be noted that in 2014, the year of anticipated maximum oil and gas production at the
Balloch field, the P10 Balloch oil and gas production profiles are less than 8 % greater than the GPIII
2011 profiles. Maximum water production at the Balloch field is associated with 2016 with an
anticipated annual production of 1.26 million m 3 . This production is approximately 32 % of the PW
volumes associated with the GPIII 2011 production. In Section 5, a conservative approach is applied
to predict fuel use at the GPIII following the development of the Balloch field and assumes an increase