Koil Energy Solutions Inc. (KLNG)

[JoeSmith]

Cutting edge tech, 1918

"Towards the surface,
backscatter tends to be
plentiful, providing sufficient
reflections for the ADCP to
operate at maximum efficiency;
however the deeper you go in
the ocean, the less
backscattering occurs. This
substantially limits the range
of any current profiler, and
effectively prevents it from
collecting a 2000m profile.
To overcome this, recent
validation trials have proven
that by mounting the ADCP on
the sea floor facing upwards, it
points into the area of the
stronger backscatter, thus
dramatically improving the
range that would otherwise be
obtained by a downward-facing
instrument deployed at the same depth.
Incorporating acoustic
modems to transmit bi-directional data in
real time has a further advantage in that
it allows real time manipulation – and
hence enhancement – of the ADCP’s
performance.
Armed with this information, Shell
Global Solutions (US) and RD
Instruments, working in co-operation
with Floatation Technologies, Linkquest,
and Evans-Hamilton, set about designing
a downward/upward-looking system for
offshore operations.
A validation test for this configuration
was performed in the Gulf of Mexico,
where Shell Oil was drilling from the
Transocean Sedco Forex Deepwater
Nautilus semi-submersible in 1574m
water depth. The rig was already fitted
with an RDI 75kHz Vessel Mounted (VM)
downward-looking ADCP mounted in the
rig’s port pontoon some 9m below the
surface. This current profiler provided
real time data for the top 600 – 800m of
water.
An RDI Workhorse Long
Ranger 75kHz ADCP was
chosen as the bottom-mounted,
upward-looking instrument.
The main reason for the choice
was that this instrument has
the longest profiling range, up
to 600m, of any self-contained
current profiler available."

http://www.rdinstruments.com/articles/offshore_eng_0402_rdi.pdf