Rise of The Umbilicals
Probyn, The Senior Structural Analysis Engineer
at DUCO Ltd., Technip, UK gives Energy
Outlook an insight
into the manufacture, working and the significance
of umbilical systems at DUCO, Technip.
Probyn is responsible for development of finite
element analysis techniques of subsea umbilical
systems at Duco. Umbilicals are used as the control
and supply link for subsea Oil and Gas extraction
equipment. Since joining DUCO in 2004 he has been
responsible for developing and validating finite
element analysis techniques, based on Abaqus,
to assess the behaviour of the complex helical
construction of the umbilical in structural and
thermal scenarios. He graduated from Loughborough
University in 1997 with a Bachelor’s degree
in Automotive Engineering and worked as a crash
simulation engineer for Rover, BMW and Land Rover
where he developed vehicle body structures for
crashworthiness using FEA software.
An umbilical is the control
link that goes from either a floating vessel or
a fixed platform down to the sea bed and connects
into sub-sea equipment for oil and gas extraction.
Umbilicals can either be static, where they are
laid upon the seabed, or dynamic where they hang
in the water column and are subjected to fatigue
loading. There are of four general types- steel
tube, thermoplastic hose, power cable and the
In terms of supply, the umbilicals carry chemicals
supply for injection into the flow-line for flow
assurance, electrical power supply and hydraulic
power supply. In terms of control, the umbilical
provides hydraulic and electrical control signals,
and also optical control signals via fibre optic
DUCO LTd. &
DUCO’s main facility
is located at Newcastle upon Tyne in the UK. We
have four manufacturing facilities: Newcastle-UK,
Houston-US, Angola-West Coast of Africa and there's
a new facility that is scheduled to commence its
operations this year in Malaysia.
Since 2003 DUCO has been part of the Technip group.
Technip provides full oil and gas capability in
sub-sea, offshore and onshore, as well. When it
comes to sub-sea equipment, Technip, designs,
manufactures and installs, umbilicals, flexible
risers, rigid pipelines. In terms of offshore,
Technip is capable of engineering and construction
of fixed or floating platforms adapted to all
water depths for oil and gas production at sea.
Onshore, Technip engineers and constructs all
onshore installations for the oil and gas, petrochemical,
and non-oil industries( including chemicals, life
sciences, renewable energies…) So, the umbilical
system is only a small, but vital, piece of the
jigsaw puzzle which makes up a complete offshore
Umbilicals in deep
In deep waters, installation
becomes very critical especially when it comes
to being able to provide enough 'crush-resistance'
to the umbilical to be able to hold on to it in
an installation caterpillar. Finite element analysis
can be used to assess the crush performance of
the umbilical and ensure that the components inside
are not likely to get damaged. For example, we
can determine the upper working limits of those
components and make sure that the umbilical system
is installable with existing lay equipment.
no one makes them better than Duco Ltd.?
Every umbilical system is
purpose designed for the particular function and
at Duco Ltd., we place a strong emphasis on research
and development and engineering efforts. We thus
have a very good resource of engineering back
up. We also have very good quality systems for
design and manufacture.
DUCO and Umbilicals
the only products that Duco Ltd. manufactures.
We also design the end termination systems and
the sub-sea foundation equipment, for example
mud-mats which sit on the sea bed supporting the
end termination, enabling the umbilical to be
connected in to the field by an ROV. We also design
and manufacture the connector, or jumper umbilicals
that join the main umbilicals from the end termination
into subsea equipment such as ; christmas trees,
manifolds and well-heads.
Umbilicals: The Components
Some of the key components
that go into the umbilical are steel tubes, thermoplastic
hose- where the hose is made out of extruded polymer
liners and has a braided Kevlar reinforcement
to give it pressure retention and tensile strength,
electrical cables, both signal and power and fibre
optic cables. If it's a steel tube umbilical then
the steel tubes provide the tensile strength,
if it's a thermoplastic or power cable umbilical
then there's a steel armour layer that's applied
and that provides the tensile strength.
The umbilicals are helically laid and that provides
flexibility in bending so the functional components
are not over-stressed during bending.
Dynamic Umbilicals: The
Anti- Fatigue Design
The design requirements
of dynamic umbilicals are considerably greater
than that of the static umbilicals. The static
umbilical, once installed on the sea-bed, is relatively
benign. There are some instances in shallow waters
where there's strong currents and the umbilical
may need to be buried to prevent it being damaged
or we can design it so it's has sufficient mass
to keep it stable on the sea bed.
For a dynamic umbilical, which is suspended from
a vessel, we need to think about fatigue and make
sure that the steel tube components don't have
metal to metal contact, therefore they are over-coated
with a polymer material. We also need to design
a bend stiffener, so that at the connection point
with the vessel , the bending movement is controlled
to avoid over-bending which may cause damage to
the umbilical components.
We perform all the engineering, based on validated
methods, to prove that the fatigue life of the
umbilical is going to be sufficient for that particular
installation. This can be very dependent upon
the type of vessel that the umbilical is attaching
to, i.e. whether it's a spar or an FPSO, as the
dynamic motion can vary between types of vessel.
of Indian market to Umbilicals from Duco
A very positive one, indeed.
Certainly, people coming to the stand(Technip
- Oceantex 2010) say that they enjoyed the presentation
Future of Indian
The energy demand for India
is predicted to increase. The amount of energy
that's being imported in terms of hydrocarbons
is a high percentage, so I think India is making
itself more self sufficient when it comes to energy
supply. I think there will soon be more development
in the offshore business in the future.