In the second half of 2010 Hydrex carried out a full inspection and removed all fouling from three drilling vessels in the Gulf of Mexico owned by Transocean, the world’s largest offshore drilling company. This was done to reduce the weight and drag of the vessels and increase their available deck load.
Fully equipped and operational, all Hydrex offices are ready to mobilize immediately to carry out high quality and fast underwater cleaning operations or any other maintenance and repair work on offshore units and ships located in fields.
By taking advantage of a range of underwater cleaning units designed in-house specifically for offshore operations, all types of fouling can be removed from any type of offshore structure. An all-embracing combination of single, twin and triple head cleaning machines is used. The twin head MC212 unit is designed for cleaning light, medium and heavy marine fouling from tubular pipes, bracings and legs of offshore oil and gas platforms, jetties, piles, intakes and ship hulls. The triple head MC312 Typhoon machine is easily adaptable to the shape of a ship or pontoon hull. Its heads self-adjust to the contours of the hull making complex areas far easier to clean. Even thick layers of hard marine growth of more than 10 inches can be removed by Hydrex cleaning. If required a special reclaim system can be added to the equipment to prevent the removed fouling from spreading in the environment.
By removing all fouling from an offshore unit its weight is reduced and the available deck capacity is increased. A cleaning operation also facilitates any needed visual inspection or non-destructive testing. This allows owners to be in total control of their unit’s hull condition.
Hydrex also offers considered preventive and protective maintenance services that are highly effective and save a great deal of time and money in comparison to the costs incurred during a breakdown for which there has been no preparation. With preventive engineering and scheduled maintenance, work delays can be eliminated or reduced significantly.
Underwater maintenance work performed on drillships in the Gulf of Mexico
For the maintenance operation in the Gulf of Mexico, an inspection team and two cleaning teams were mobilized from the Hydrex offices.
Hydrex had carried out repairs on other offshore units belonging to the same owner and he knew that the company could offer the required services without having to take the vessels to drydock. “We’ve known Transocean for a very long time,” says Hydrex Senior Project Manager René Huybregts. “We first met during projects carried out on a big offshore repair yard in The Netherlands some years ago. We stayed in touch ever since, assisting them with the design and procedure for installing specific types of cofferdams and performing other repair work.”
Impressed by the complete package of both engineering and project management that Hydrex offers, the owner then asked Hydrex to perform the inspection and cleaning of one of their drilling vessels in the Gulf of Mexico. Satisfied with the way the operation was handled, a second and third drilling vessel were soon added.
The scope of work consisted of a comprehensive UWILD inspection of the three vessels, and an inspection of the weld seams in particular, and a cleaning of the underwater parts of the units. Replacement of anodes was also performed wherever needed and all overboard lines were blanked in order to enable inspection from the inside. The Hydrex teams also assisted with the removal of one of the vessels’ thrusters so that they could be overhauled.
While a surveyor was monitoring the team that was carrying out the inspection required by the classification society, an underwater cleaning team was working simultaneously to make sure that the operation would be finished within the available timeframe. For the same reason, one of the teams was transferred to the second vessel to begin the second operation while the other teams finished the underwater cleaning work on the first unit.
The vessels were away from the field and because the crew also needed to carry out other maintenance and repair work on the vessels a very tight schedule had to be followed. This schedule allowed the team to plan the inspection and cleaning operation around the other work. Flexibility is a very important factor during a large operation like this. Hydrex teams are trained to adapt themselves to the customer’s program as much as possible instead of the other way around.
“We have gotten very good feedback from the customer,” says René. “The way we handled a big operation like this was highly appreciated. This is very important for us. The customer needs to be satisfied with the result. We work very hard to keep improving our services to make sure that we can work out the best possible solution for any problem that a customer might be faced with.”
On-site repair services and full project management for offshore/support units
Besides tailor-made maintenance operations such as the one described above, Hydrex also has the know-how and expertise to provide comprehensive on-site repair services and project management for offshore related units. These projects are engineered and carried out by Hydrex in close cooperation with the customer. Starting from the design and construction of equipment all the way through to the actual repair or replacement and subsequent follow-up.
One possible action that can be taken is to install a permanent thruster repair and replacement system. This system has been developed so it can be tailored to most vessels. It can be included in the planning for a newbuild, installed on a unit going to drydock or constructed and brought onboard at any other suitable time. With such a system on standby, any repair work to the thruster that may arise can be dealt with much more quickly and easily.
Hydrex also offer a wide range of possible repair services that make use of specially designed cofferdams. These can be rigid or flexible depending on the type of repair.
Going to drydock is often not a feasible option for offshore related units because of the down time, loss of production and subsequent financial setback this brings about. Using cofferdams allows for a wide range of repairs to be performed while normal operations at sea are maintained. Hull, thruster, seal and spud can repairs are some of the most common underwater repairs made possible by the external cofferdam technology.
These turn-key projects are planned and managed by Hydrex in close cooperation with the customer. It includes formulation of safety guidelines, writing working procedures, design and construction of cofferdams and any other necessary equipment all the way through to the repair or replacement.
If a problem occurs the Hydrex technical department can take the project out the customer’s hands and find the most viable solution. Within a very short timeframe Hydrex diver/technicians can be on site solving the problem.
Our technical department and diving teams are trained to carry out exact procedures and deliver a professional product or service while minimizing off-hire time yet maintaining high quality. All Hydrex diver/technicians are also fully certified and can be mobilized immediately. A good example of this is the recent emergency inspection and insert job on a semi-submersible vessel that was carried out in Malaysia in only five days. A fast response such as that can save precious time for customers in the case of an emergency or tight deadline.