OGI: What
testing?
FMD Reporting Software - Flooded.
is
FMD
Lucinda: Flooded Member
Detection is an inspection
regime designed to screen
an offshore platform’s
subsea structural members
for defects. A cracked weld,
for example, can allow the
ingress of sea water into
the member which may
go on to create a point of
failure for the structure.
Operators therefore need
to inspect these members
on a regular basis to gain
confidence that there has
been no sea water ingress.
There are 2 recognised
methods by which subsea
members can be inspected:
via UT (Ultrasonic Testing)
or via radiation (often
referred to as “Gamma”).
We have recently designed and launched a UT
FMD system.
OGI: Could you talk a bit about Cygnus FMD?
Lucinda: We observed that in the past, FMD
with UT had not gained as much respect from
the offshore inspection industry as we felt it
should have done.
We identified that this
was because previous generations of UT FMD
equipment had not been produced by a specialist
design house with the right in-house knowledge
or experience. Older equipment might have
been able to do the job in a test tank but could be
tripped up by thick walled members or by heavy
corrosion when subsea in the real world.
subsequently allows either the technician
on the survey, or an off-site engineer at a
later date, to confirm the result is absolutely
correct. well for our customers.
Other considerations have also been taken
properly in to account; there is a 4-way gimble
built around the Cygnus transducer that
ensures correct transducer alignment; and the
system has a transducer contact sensor – to
let the topside technicians know the ROV or
diver has made good contact before a test is
conducted. Lucinda: Surveys using the Cygnus UT
equipment have now been successfully
completed by all the major contractors for
almost all of the Tier 1 Operators; from
Saudi Arabia to the Gulf of Mexico and from
Western Australia to the North Sea. Endless
members have been inspected and many
buoyancy tanks checked. As mentioned
above, the fact that we have offered a truly
reliable and viable alternative to gamma - and
delivered it in a package that is aimed solely
and squarely at its end application - has meant
that uptake has been extremely good.
OGI: Has the offshore industry accepted the
new Cygnus System?
So, we committed to the project and embarked
on a full engineering development and trials
cycle; we invested heavily because we knew that,
done properly, a fully developed, professional
UT system should and would play a much
greater role in FMD in the future. Lucinda: While some degree of surface
preparation is often needed for UT FMD on
Members, that perceived disadvantage will
very often be outweighed by cost savings on
the equipment itself - and further savings due
to operational flexibility.
The result is, therefore, that the Cygnus Flooded
Member Detection (FMD) system is the only
one of its kind that is designed by a dedicated,
ultrasonic NDT (Non-Destructive Testing)
specialist. The Cygnus system’s advanced signal
processing and low noise data acquisition
will work on thick-walled (up to 75mm thick)
members and pipes, on heavily corroded
members and on buoyancy tanks. These are all
areas and applications that previous generations
of UT equipment would stumble on. Because the Gamma Technique uses a
radioactive source, the equipment and
inspection will be provided as a service
by a third-party contractor. To operate
radioactive equipment one, or often two,
specialist technicians must be deployed with
the equipment; and they will then take up
precious bed-spaces offshore.
We are thus aiming to attract the end user who
is committed to using the best quality equipment
possible – the customer who wants to eliminate
any doubt and provide watertight reports. In
other words, who are themselves also leaders
and specialists.
While the equipment is extremely simple
to understand and use (it simply presents a
“Flooded” or “Dry” result), that result is backed
up with a true, rectified A-Scan. This extra layer
of information that is available allows for more
interpretation of a result - and
However, because the Cygnus UT equipment
is so simple to operate, existing personnel
from the diving or ROV team will perform the
inspection work themselves – which of course
immediately creates a very valuable cost saving
for the contractor. And again, because the
Cygnus equipment is owner operated and so
cost effective, it is cost effective for the Cygnus
system to be permanently available on an
offshore vessel or platform until it is needed;
thus flexibility is offered because inspections
do not have to be precisely timetabled and bad
windows of weather can be allowed to pass.
Due to this, feedback has been unequivocal
that the Cygnus FMD system is working very
OGI: Finally, could you enlighten our readers
of a case study where you helped a client with
your solutions
After using the Cygnus FMD system Louis
Pietranek of Westerton Access commented
that “the new Cygnus Ultrasonic FMD System
was perfect for our recent application. Our
technicians found the software to be very
easy to use with features that ensured a quick
and reliable result. It’s a great addition to the
Westerton Access capability, offering FMD
inspection from the Falcon ROV”.
And that is what Cygnus is all about: we
harness four decades of ultrasonic knowledge
and sector experience in order to offer a
simple, practical solution that enables our
end users to get clear, reliable results; and in
doing so we aim to offer a real value-add to
the industry.
OGI: Thank you for your time. •
If you’d like to know more about the topics
discussed in this article, and/or would like to
know how Cygnus Instruments can help your
operations, please contact us via:
Web: https://www.cygnus-instruments.com/
Phone: +44 (0) 1305 265533
E-mail: [email protected]
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