English - Putzmeister Solid Pumps

Site report
Special pumps for process water
The Norwegian state company
Statoil Petroleum ASA operates in
the rough North Sea, with the
world's largest floating gas production
platform, called Åsgard B.
Working together with the crude oil
production vessel Åsgard A and the
bunkering vessel Åsgard C, it is lo -
ca ted on the Halten Bank, approx.
200 km north-west of Trondheim
on the Norwegian continental
shelf.
Put into service in 2000, the Åsgard B
extracts approximately 36.2 million
cubic meters of natural gas per day from
the fields of Midgard, Smørbukk and
Smørbukk South from a depth of 240 –
300 m per day. With this amount of natural
gas one could heat up approximately
6.5 million households for one year. In
May 2011, Putzmeister Solid Pumps
supplied a specially developed double
piston pump with ball valve head, which
is used for the disposal of process water,
that has been produced during natural
gas processing.
Before being used on a daily basis for
cooking or space heating, natural gas
has travelled a long way. Natural gas
resources used today are mostly located
in regions with extreme weather condi -
tions, such as in the North Sea, just
south of the Arctic Circle. Before this gas
passes through hundreds of miles of
pipelines to reach us, it has undergone
costly processing, process technical preparation
and purification.
File under: A 1.00, A 4.00, IP 4.05
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Natural gas production platform Åsgard B (Photo Øyvind Hagen, © Statoil Petroleum ASA)
IP 4383 GB

During this process, health and environmentally
hazardous substances are
released and must be disposed of, with -
out exposing humans, animals or the
environment to risks. Drip water –
so-called process water is such a substance.
Gas platform workers call this a
"cocktail"; a mixture containing salt
water, petroleum residues, tars and a
series of hydrocarbon compounds,
which poses several challenges for process
and plant engineering.
In the past this production residue was
disposed of with much effort and at high
cost. Today, economic aspects demand
an environmentally friendly and costefficient
waste disposal. Currently, the
drip water is pumped back to the treatment
process with piston pumps via an
elaborate network of pipes and valves.
The gaseous substances are separated
from liquids by disposition and separa -
tion devices and processed separately or
disposed of.
The challenge lies precisely in this specific
pumping process. While the requir -
ed output of 24 m³ per hour, at a pump
pressure of up to 87 bar is a solvable
technological challenge, the pumps currently
in use suffer from enormous wear
and tear. This is caused by the various
types of foreign objects, for example,
silicate-containing sand. The wear caus -
ed by foreign bodies leads to frequent
failure of the pumps, which causes high
maintenance expenses each month and,
in worst cases, a loss in production.
Development and manufacturing
Due to the very specific requirements in
terms of mechanical, electrical and
hydraulic design it took two years of
development and manufacturing before
the pump and the hydraulic drive unit
could be delivered. This two-year process
has been successfully completed
with our customer Statoil and the Nor -
wegian engineering company.
The following requirements are parti cu -
larly noteworthy:
Dangerous substances need comp -
lete shielding from the environment.
This is ensured by the pump’s closed
water tank.
In order to optimise the resistance
behaviour of the pump to the abra -
sive wear and the thermal and
mechanical stress, the pump head
was made of chrome, duplex, steel
and Viton piston collars and a hard-
chromed conveying cylinder. Fur thermore,
the entire steel structure is
protected from the salty air by a
special coating.
Limited available space on the production
platform necessitates a high -
ly compact design, which must also
be suitable for transport.
The potentially explosive atmosphere
on board requires all electrical components
to be in compliance with
ATEX guidelines.
Finally, to support the technical process,
a virtually pulsation-free pumping
is necessary. This requirement
is achieved using the PCF method
(pressure constant flow ® ) developed
by Putzmeister.
The compliance with customer specifications
and specific offshore provisions,
e.g. the NORSOK Standards
which state explicit requirements for
design, fabrication and materials
could be demonstrated in the presence
of the customer during the
acceptance test bench run.
The Castle of Gods Åsgard
In Norse mythology, the castle Åsgard is described as the abode of the gods
of the Aesir.
It is located in the branches of the world ash Yggdrasil above Midgard, the
realm of men and Utgard, the realm of giants and trolls.
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IP 4383 GB

Putzmeister PCF -Control ®
Putzmeister Solid Pumps now offers PCF
control as an option for virtually all pump
valves. This is used when, for example, a
process requires a a low-pulsation material
flow, or when a reduction in noise is
desired.
P [bar]
Q [m 3 /h]
2
Moreover, the service life of plant components
and pipes can be significantly
extended due to lower pressure surges
and the resulting reduction in mechanical
stress. Technically, the low pulsation
conveyance is guaranteed by two independently
driven hydraulic cylinders
which are synchronised so that pressure
drops and pressure peaks optimally
adjust themselves. The result can be
seen in Fig.1, a virtually pulse-free pressure
history.
Low pulsation production with PCF -control
t [sec]
3
Hydraulic power pack HA 90 S
Double piston pump with
ball valve head KOV 1075
max. capacity
24 m³/h at 87 bar
pump head out of
Chrom-Duplex Steel
2 input and 2 output ball valves
2 separate hydraulic driven
delivery cylinders for a less pulsa -
tion with the control system PCF
pump in ATEX design
automatically lubrication of the
piston
over pressure dense water tank
sound absorbing elements for
lower noise emission
1 main drive E-motor 90 kW
1 E-motor for cooling system
2 hydraulic pumps for the separate
drive of the 2 pistons of the
KOV1075 pump
power pack in ATEX design
base frame and installations in
stainless steel
sound absorbing elements for
lower noise emission
very compact construction
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IP 4383 GB
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Specially trained service
personnel
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In order to ensure a swift and reliable
start-up and be well prepared for
assignments, Putzmeister Solid Pumps
has its own trained staff available, which
has undergone safety and survival training
lasting several days. The training
included a simulated helicopter crash, in
Norway in accordance with the offshore
safety regulations.
Simulator for helicopter emergency ditching
Like a rock in the stormy North
Sea – Åsgard B in figures
Commissioned: Autumn 2000
Size (L x W):
114 m x 90 m
Deck area: 10.260 m²
Total weight:
approx. 47.000 t
Weight of superstructures: approx. 28.000 t
Weight of floating objects: approx. 19.000 t
Construction & development costs:
1 Mrd. US$
Operator:
Statoil
Owner: Petoro 35,69 %
Statoil 34,57 %
EniNorge 14,82 %
Total E&P Norge 7,68 %
ExxonMobil 7,24 %
Natural gas production capacity: 36,2 m³ / d
Condensate :
94 T Barrel*/ d
Operating team / crew: ca. 40
Crew cabins: 120
Designed according the
international standards and
special oil, gas, ship and
offshore standards as:
CE
CEN
Atex proofed
ISO
EN
NORSOK
DNV
NOFO
IMO
API
ASME
ANSI
CSA
UL
GOST
Quality Assurance ISO 9001
Registered company member at
German Project Management
Assosiation GPM and World Wide
Experienced Project Manager
Trained service staff with basic
safety an emergency training –
OLF / NSOC-D / OPITO / NOGEPA
*1 Barrel = approx. 159 Liter
Source: © Statoil Petroleum ASA
Registered at Achilles ®
www.achilles.no
Member of the Putzmeister Group
www.pmSolid.com
Right to make technical amendments reserved
© by Putzmeister Solid Pumps GmbH 2011
All rights reserved
Printed in Germany
(11108SC)
Putzmeister Solid Pumps GmbH
Max-Eyth-Straße 10 · 72631 Aichtal/Germany
P.O.Box 2152 · 72629 Aichtal/Germany
Tel. +49 7127 599 500 · Fax +49 7127 599 988
psp@pmw.de · www.putzmeister-solid-pumps.com
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IP 4383 GB