The Momentum Hydro Hook Support - a complete new concept for vibration control subsea,
developed by Momentum Technologies.
is limited access to the pipe or structure that
needs to be measured.
To visualize noise is another service of ours,
called NOISEVISION. It is primarily about
identifying noise sources with the help of
an acoustic camera and provide the client
recommendations for which noise sources to
focus on and how they can be mitigated. The
acoustic camera we use is hand-held, processes
sound measurement in real time and visualizes
it upon a video, much like how a thermographic
camera works, which makes it possible to
screen an area very effectively. This service is
mostly about HSE and improving the working
environment, but the technique can also be used
for root cause failure analysis of machinery.
OGI: Can you speak a bit about your vibration
control solutions for pipelines?
The Momentum TMD, a unique high frequency tuned mass damper suitable for small bore
connections.
Johnsen: One of the vibration dampers we
provide and have had great success with is the
Momentum Tuned Mass Damper (MTMD).
It is a top of the class high frequency tuned
mass damper which is clamped on to the pipe,
making the installation very easy and it is no
problem to install it during operation. Further,
the MTMD is a passive and closed system which
makes the solution even more attractive from an
installation point of view.
The damping mechanism in a tuned mass
damper, also called tuned absorber, is in short
described as that it changes the dynamics of
the structure. By adding a tuned mass damper
you will disable the structures ability to respond
to one or more frequencies, hence removing
the risk for building up energy in the system
through resonance. It is a well proven technology
for mitigating vibration in many different
applications. The MTMD however is unique
with regard to that it mitigates resonance above
ca 20 Hz and up to about 500 Hz and operates
in all six degrees of freedom, which for example
makes it very suitable for solving vibration
problems in small bore gas piping, often caused
by flow induced pulsation. At the Momentum
Youtube page the MTDM is demonstrated:
https://youtu.be/c2wY4rtFURM
The name «Tuned Mass Dampers» indicates
that the damper needs to be set up correctly
(is «tuned») in order to obtain good vibration
reduction. Momentum Technologies provide
tuning and optimization of the dampers as part
of the delivery. This is made in cooperation
with the client and an interface is established,
through which necessary parameters are shared
(for example characteristics of the dominating
modes). The parameters are then used in a
proprietary calculation tool where multi-
mode optimization is made, seeking the best
damping solution. If measurements are needed,
Momentum Technologies can provide this
service as well, or provide procedures of how to
carry out these if the client chooses to use a local
service provider instead. This methodology
can of course also be used for other types of
vibration dampers as well, and it allows us to
work world-wide with these deliveries.
OGI: Can you tell us about your latest innovation
– the Momentum Hydro Hook Support?
Johnsen: The Momentum Hydro Hook Support,
the HHS, is a totally new damping concept for
vibration damping subsea. It utilizes a novel
damping technique through which the
dampers geometry captures the surrounding
water, turning it into a damping mass and
literally “hooks” the pipe to the surrounding
water.
It is a universal vibration damper well suited
for subsea flexibles and applications such
as flex-loops, jumpers, risers and transport
pipes that are exposed to flow induced
vibration (FIV) and vortex induced vibration
(VIV). The HHS is clamped to the pipe and
needs no foundation, it is a passive system
with a minimum number of parts and there
is possibility for retrofit of the damper. In
other words, do the HHS has many attractive
attributes. We have patented this concept and
experience a big interest in the market by
subsea suppliers.
We got the idea to the HHS in 2017, and
since then has the concept been matured step
by step. At the time of writing the concept has
been physically proven and we are now ready
to go full-scale prototyping and testing.
OGI: What are some of the potential scenarios
companies would face if they don’t take care of
an identifiable vibration issue?
Johnsen: Vibration may lead to fatigue in
pipes. And fatigue is the cause to more than
20% of pipework failure in the British oil
and gas sector (according to Health & Safety
Executive, UK). Hence a pipework failure will
imply oil or gas leak – the potential scenario
of an unsolved vibration problem is serious.
I believe that major accidents are what all
within the business fear the most, and that is
why vibration issues needs attention until
the risk of piping failure has been cleared or
solved.
OGI: Finally, could you enlighten our readers
of a case study where you helped a client with
your solutions?
Johnsen: Momentum got involved in a project
where they had issues with vibration in an
inlet module, and where one predicted a future
change in the well stream that would lead to
even higher and most probably unacceptable
levels of vibration. Within the project one had
planned to modify the pipelines, but there
were uncertainties if that would be enough.
When we were involved, we introduced the
possibilities of what a damping solution could
provide, and the client decided to also install
dampers in addition to modify the pipes.
Momentum performed measurements after
the implemented modifications and damper
installations, that shows that one now has a
construction that will be able to handle also
increased vibration levels without needing to
set limits to the future operation rates. In this
particular case we would even dare to insist on
that the damping solution alone would have
been enough, and that the quite complicated
and expensive modification of the pipes could
have been omitted.
OGI: Thank you for your time. •
If you would like to know more about the
solutions discussed in this article please
contact:
Momentum Technologies AS
E: [email protected]
T: +47 93 01 70 03
W: www.momentumtechnologies.com