leak site with a specialized spraying wand clutched in an
articulated arm. This enabled the dispersant to be injected
directly into the oil leak. Over 590,000 gallons of dispersant
had been used during the first half of May.
Inspection. Following the sinking of the Transocean
Deepwater Horizon rig, the ocean floor was littered with
over 5,000 feet of twisted, mangled pipe that constituted
the rig's main riser pipe. It was through this pipe that
several leaks were gushing crude oil into the surrounding
water. ROVs equipped with video cameras were employed
to scour every square inch of this pipe, relaying this vital
visual data via fiber optic cable to engineers at the
Response Command Center.
Manipulation. Since the first day following the
accident, engineers were convinced that the fastest and
easiest way of stopping the oil leak was engaging the ram
locks on the BOP. ROVs relentlessly toiled at activating the
BOP. This effort was ongoing, even while other attempts
were being made at stemming the flow of oil from MC252.
Construction. As incredible as it may sound, while all
of these other salvage tasks were being performed, another
set of ROVs were being used for building a shutoff valve
inside the leaking main riser pipe. Actually, this work is
more along the lines of a traditional ROV role — tirelessly
toiling underwater building a widget faster than it would
take human divers to complete. And at nearly one mile
down, this time savings is extremely valuable. According to
the ROV industry, ROVs can work for days, whereas divers
can only endure several hours underwater. Likewise, a
skilled ROV operator can perform almost every function
that can be performed by an experienced diver.
This entire operation doesn't come cheap. During the
height of the Deepwater Horizon response effort, BP was
spending over $6 million per day.
Stanching the Flow
By May 17, 2010, the round-the-clock work of BP's
engineers was beginning to pay off. A five foot long section
of pipe had been equipped with rubber seals for holding
back seawater. This rubber-fitted capture pipe — known as
Terminology Used in
Oil Spill Containment
BOP — Blowout preventer.
Hydrates — Ice-like formations of methane and water that
occur in seawater at low temperature and high pressure.
Junk shot — Clog the BOP with golf balls and rubber tire
pieces prior to attempt a top kill.
RITT — Riser insertion tube tool.
ROV — Remotely-operated vehicle.
Tophat — A containment funnel used to channel oil to a
surface collection/processing vessel where the oil is
separated from seawater.
Top Kill — Filling the BOP with heavy drilling mud followed
by capping the well head with cement.
How to do a "top kill" on the stricken MC252 BOP.
SERVO 07.2010 59
