The
discovery of new promising oil and gas fields results in increasing activities to develop
Brazil's rich energy resources.
One of the major players in the Brazilian oil and gas industry is Petrobras.
The use of the latest exploration technology, in combination with high-tech production
equipment, is the key to their success.
Manas, capital of the state of Amazonas, is an important transit port for ocean-going
vessels, providing export facilities for many national and international companies.
Here in Manas, Petrobras installed two gas pipelines to connect the city with the gas
production center in the province of Uruguay.
Dutch dredging marine and offshore contractor Van Oord is contracted to protect and stabilize
the pipeline crossing over the Rio Negro by means of an advanced technique, subsea rock
installation.
Flexible fall pipe vessel Tertness is mobilized to Brazil to execute the first subsea rock
installation project in the country's history.
Commercial manager Hans Bayern works for Van Oord head office in the Netherlands.
Right from the beginning, after the Petrobras tender, he coordinated the rock Manas project.
Even for the well-experienced company as Van Oord, this location was a challenge.
The biggest challenges for us were two-sided.
This project is executed in an area where we have never been before, in the middle of
the Amazon.
We are used to implement such projects at sea.
So an area we are not so familiar with, a challenge in a new country for a new customer.
The second major challenge is the logistics.
We needed about 40,000 tons of rock, and that had to be taken from the interior.
That had to be done by truck and by river barge.
Those were our two biggest challenges to make this project a success.
Prior to the execution on site, the Van Oord project team works in close cooperation with
the Petrobras staff to prepare specific project plans and security procedures.
The rock that will be installed on the seabed originates from a quarry that is located inland.
To guarantee efficient and safe operations during all times, new tailor-made facilities
to load and stockpile the rocks are being built.
All operations are executed in accordance with strict international offshore safety
standards, as well as Van Oord and Petrobras security procedures.
At the quarry, the rocks are pre-selected by size and diameter to meet the design specifications.
Bert Baumeister is Van Oord's operation manager in Brazil and involved with the daily progress
of the rock installation project in Manass.
As well as for him, this new project showed challenges right from the beginning.
The difficulty factor in the beginning we have to deal with were the problems in the
quarries.
The screening plants and conveyor belts, they could still handle these small ones, but they
had huge problems with these big stones, so that took a long time before we were in line
with the quarries, so they would be able to break up and crush these stones, thereby meeting
the requirements that we were contractually obligated to Petrobras.
This great, these little ones, and the percentage in between.
The rocks are transported from the quarry to the main terminal port and loaded onto special
cargo boats that carry the rock to the flexible fall pipe vessel at the port of Manass.
Once loaded, the turtleneck sets course to the project site.
Since the work location, the vessel uses the dynamic positioning system to maintain its
position during the operations.
This is essential to achieve optimum results during rock installation.
With the vessel in position, the crew makes the final preparations to launch the ROV and
the flexible fall pipe.
The ROV is lowered. With the aid of highly sophisticated survey equipment, the engineers
start to conduct extensive pre-surveys of the work location to confirm the status of
the underwater site.
This data will be used as a basis for control and verification of the rock installation.
The flexible fall pipe is now brought into position.
The ROV is used to maneuver the flexible fall pipe, whilst all underwater operations can
be closely monitored with the aid of underwater cameras.
This enables the crew to install the rock with an extremely high level of accuracy.
The installation of rock can begin.
From the vessel's hold, onto the conveyor belt, via the hopper on deck, into the feeder,
which precisely controls the flow of rock material into the flexible fall pipe.
During installation, the progress and accuracy of the works are continuously verified and
discussed with the client.
Once the Tertness has installed the rock, the team performs a post-survey.
With the results of this final survey, the crew has immediate access to the outcome
of operations, ensuring that the design specifications are met or even exceeded.
With the final approval of the client in place, the first subsea rock installation project
in Brazilian waters has been successfully completed.
With their extensive experience in subsea rock installation, Van Oord looks forward
to contribute to the future expansion of the oil and gas infrastructure in Brazil.
At all times, offering safe and efficient solutions for subsea pipeline protection and stabilisation.
