key components were precisely fabricated—
to the nearest micron—and tests often lasted
several weeks.
Assembly was likewise complex for facilities
such as the FPU. Composed of 13 separate
topsides modules, it required extremely detailed
calculations for correct assembly and installation.
The module-lifting operations were a major
challenge: HHI chose for the task the biggest
floating crane in the world, with a 10,000-ton
capacity. Built by and for HHI, it was used—for the
very first time—to lift the Moho Nord TLP deck.
WHAT GOES UP MUST COME DOWN
Even trickier was the procedure to lift the TLP’s
topsides onto the hull—considering that the
topsides measures 56 by 55 meters by 16
meters high and weighs more than 5,000 tons.
Preparations and simulations continued for
several months before the heavy lift took place
in April 2015. It was essential to eliminate any
potential risks to workers and asset integrity
posed by the possibility of tipping, the handling
of heavy objects, or work at height.
The two-day operation—a formidable
technological challenge—required 180 people,
including naval and structural engineers,
quality and safety officers, constructors, crane
operators and vessel crew.
The topsides spent a full night hanging over
the water before it found its permanent home,
fastened to the hull at four connection points to
within 2 centimeters—a resounding success!
Another particularly difficult operation was
installing the deepwater facilities on-site. Aside
from the inherent risks of working at sea,
both the powerful currents in the area and the
unpredictable weather conditions combined to
shorten the windows for operations as the work
progressed.
THE TLP: A MAJOR INNOVATION FOR TOTAL AND THE REPUBLIC OF CONGO
A development plan using a TLP and surface wellheads is a first
for Total. It enables us to produce the Albian carbonate reservoir,
whose deposits are very hard and require frequent well intervention.
Built by Hyundai Heavy Industries (HHI) in South Korea and
delivered to the Republic of Congo, the impressive floating platform
is moored with 12 tendons attached to piles driven into the seabed.
We carried out this challenging installation with a crane vessel and
remotely operated underwater vehicles. Our goal was to guarantee
the unit’s stability by controlling the movements caused by ocean
currents, while ensuring a production capacity of 40,000 barrels of
oil per day, with simultaneous drilling and / or well interventions.
