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Oilfield Technology
August
2015
Mainair compressorpackage for theShahDeniz
oilfield
Comprised of three ZR500 water cooled screw compressors, a
closed circuit water cooling system, three heatless dryers and
separate ZT110 black start screw compressor for emergencies,
the package was purpose designed, built and fully tested at
Atlas Copco’s Systems Hemel Hempstead workshop before being
delivered to the Shah Deniz project.
Once installed, the main air compressor package will provide
instrument air for pneumatic controls and actuation of critical
valves and instruments on the offshore platform. Under normal
operating conditions, two of the compressors will be running
continuously to provide 100% of the platform’s instrument air
requirements. However, in the event of non‑availability of one of
the compressors, the third, standby compressor, will start and
provide the necessary capacity. In the event of a power failure
and loss of the main air compressor package, the black start
air compressor, which is supplied by the platform’s emergency
power generator, will start and provide the minimum
compressed air needed to safely shutdown the
platform operations.
Logistical challenges
The delivery of the package marked the completion
of another major project by the team at Atlas Copco
Systems Hemel Hempstead.
As with most orders received by the facility, the
brief for the Shah Deniz package came with a very
particular set of specifications.
Not only did three heavyweight compressors
need to be combined on a single skid but a number
of ancillary items were also required, and the entire
package had to be sufficiently robust to withstand
harsh and fluctuating environmental conditions.
Due to the exposed nature of the offshore
platform where it was to be installed, the
main air compressor package needed to be
weatherproofed, winterised and built to withstand
harsh environmental conditions including high
wind speeds of up to 45 m/s and ambient air
temperatures ranging from ‑7 ‑ +40˚C at high relative
humidity. Designed for continuous 24 hr operation,
the package was tested to withstand inertial
accelerations as a result of seismic activity and
was also soundproofed to operate with low noise
emissions.
The physical size of the main air compressor
package, which is over 11 m long, 6 m wide and
3.75 m high, meant it had to be delivered in a
reinforced crate along with specially designed lifting
equipment to support offloading and handling at its
destination. This brought the total size of the final
delivered package to almost 90 t, which was moved
from the workshop using a 12 t fork lift truck onto
the back of a special heavy load bearing lorry that
travelled via police escort to Immingham docks for
shipping to Baku. During transit, the package then
travelled via canal, timed to avoid freezing weather
conditions, from the Black Sea into the Caspian Sea
for installation on the platform.
PackagedsystemforKazakhstan
Despite its extraordinary requirements, the Shah Deniz project
provides a useful illustration of the type of demands handled
by Systems Hemel Hempstead in the UK, one of Atlas Copco’s
six global competence centres that create and assemble bespoke
compressed air and nitrogen generation installations for the oil
and gas industry.
In 2012, the company completed the delivery of its largest
ever order designed and built in the UK. The system, comprising
instrument and process air compressor modules, and worth in
excess of £6 million, was so large in scale that one of the largest
air freight transporters in the world, the Antonov 124, was
commissioned to deliver it to Kazakhstan, where it continues to be
deployed as part of a major oil and gas project.
The four modules had to be fitted with special ‘D’ rings so that
they could be pulled, with just millimetres to spare, into the front
loading bay of the Russian‑built Antonov 124 and then secured
during flight.
Figure 1.
Recent package for the ShahDeniz project during loading.
Figure 2.
In 2012, Atlas Copco commissionedan Antonov 124 to transport its largest ever
package to a customer based inKazkahstan.
