APPLICATION: ADCP mounted on an ROV
Innovative ROV/ADCP Combination
Fugro GEOS Innovation in Gulf
|Here is the RDI 300kHz ADCP being mounted on the drillship’s ROV. The ADCP has a deep water casing, since it gathered continuous data as the ROV moved from surface to bottom in the 8800 feet of water.
Fugro GEOS had a problem: their
client BHP was about to drill the second-deepest well in the world, on the Walker Ridge
Block in the Gulf of Mexico. The well was located at a depth of 2680m (8800 feet) in an
area where water currents could threaten the marine riser. Traditional ADCP (acoustic
Doppler current profiler) current measurement equipment could only reach up a little over
1000 meters in good conditions. What to do?
Get innovative, thats what.
Fugro GEOS has previously extended the water current
profiling ranges by employing two 75kHz ADCPs.
One was suspended below the drillship, to cover the top 450m of the water column. The
second was mounted on the blow-out preventer on the ocean floor, looking upward, to
monitor currents near the bottom. This double configuration has given good data for
But it wouldnt work in the ultra deep water areas
of the Gulf. The real innovation at Walker Ridge was the implementation of a 300kHz ADCP mounted on the drillship's ROV. This ADCP
continuously collected current profile information as the ROV descended and ascended
throughout the entire water column. One instrument, full coverage of all 2680 meters!
Fugro GEOS developed a special software package that
they call RovADCP to integrate the current velocities measured as the ROV descended in the
water column. Real-time data was made available to the drillship for the full water
column. This data, which can be used alone or combined with data from stationary ADCPs
(using Fugro GEOS RigADCP software), provides the information needed to safely
manage the drilling operation in an area of current activity. Full coverage is especially
critical in deep water, where hydrodynamics have an even greater impact on operations (due
to increased depth) and the ocean conditions are more variable and less predictable.
and ADCP, ready for deployment underneath the drillship. The ADCP data was interpreted
through Fugro GEOS RovADCP software.