The first attempt was trying to flick that switch — the
failsafe safety switch which would activate the BOP and
immediately seal the wellhead. This attempt was ongoing
during the entire response effort.
The second attempt performed by the ROVs seemed
almost counterintuitive. While continuing the BOP salvage
efforts, a second squad of ROVs were preparing the BOP to
be killed. Known as a "top kill," this response would
effectively cram the unresponsive BOP with junk — including
golf balls and automobile tires called "junk shot" — then
"seal" the deal with a stream of specialized heavy fluids
called drilling mud that would prevent continued oil flow
through the BOP. In an oversimplified analogy, a top kill
would perform a result similar to that which would be
obtained from a functional BOP.
While two groups of ROVs were occupied with
removing control panels, mending some cabling, and
fiddling with the failsafe switch, a final group of robots
orchestrated an entirely different attempt at curbing this
looming ecological disaster.
A small dome called "Tophat" was shipped out to the
accident site and lowered to the seabed in preparation for
deployment. Similar to its much larger cousin called a
containment dome which had frozen up and failed on May
8, 2010, Tophat was designed to minimize the deleterious
effects from freezing hydrates. While this system had never
been used in water depths of 5,000+ feet, BP unleashed a
small cadre of ROVs for shepherding Tophat into place
while warning that its successful operation was "uncertain."
Whose Robot's Whose?
Oddly enough, not all of these ROVs swimming around
BP ROVs Role In a Nutshell
ROVs have been used in deepwater industries for more
than 30 years, mostly to carry out routine maintenance
and construction work.
ROVs are linked to the surface by means of a tether
(or "umbilical") which is essentially a group of cables that
are used to carry electrical power, video, and other data
signals between the ROV and the operator on a vessel or
onshore.
An operator can control the movements of these
highly maneuverable machines under the sea, performing a
variety of difficult operations from the safety of a vessel or
dry land. A key benefit of an ROV is that it can carry out
work without the need for human divers. Furthermore,
ROVs can work beyond the depth and pressure that a
human could safely dive.
An ROV's arms or "manipulator," are easily controlled
and have been developed over the years to have the same
range of motion as a human arm. In fact, some are so
sophisticated that they could, theoretically, pick up an egg
Main oil leak at end of riser pipe/12 Inch wrench
and ROV in background.
the wellhead are owned or operated by BP. Huh? Yup.
Unlike other industries that competitively feed off of each
other’s misfortune, in the oil industry everybody lends a
hand in taming a disaster. So, when an ROV is under
contract with a competitor and a tragic event mandates
swift undersea help, a staunch corporate foe will quickly
become your strongest ally.
In the case of the MC252 accident, ExxonMobile
became a strong supporter in providing ROV support.
Likewise, Chevron lent a hand in dealing with the
cantankerous BOP, while Shell sent a small flotilla of surface
support vessels.
without breaking it. To direct the arms, the ROV operator
at the surface holds a joystick. Some ROVs even have force
feedback mechanisms so that the operator can feel
resistance and reaction to the force being applied.
ROVs are frequently equipped with a number of
systems to aid in navigation. Most have lights and video
cameras. Some ROVs, in addition, have sonar systems
which help operators navigate safely through undersea
obstacles and terrain in murky waters. GPS systems are also
available to help track an ROV's exact location.
The vehicles typically carry a variety of specialized tools
that are designed for compatibility with subsea equipment.
Using these tools, ROV operators can manipulate the valves
and controls of sub-sea well heads.
At least 12 ROVs were deployed for various purposes
in addressing the MC252 spill in the Gulf. Some are
engaged in monitoring the well. Others are supporting
attempts to activate the blowout preventer. In other tasks,
for example, an ROV was being used to hold a wand to
spray dispersant into oil on the seafloor near the leak in
the main riser pipe.
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