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Oil and gas

Turnkey underwater repairand maintenance solutions

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® Hydrex and Mobdock are registered trademarksDesign: ADworks - www.adworks.be

Contents

ISO 9001 certified

Underwater services and technology approved by:

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Turnkey underwater repair and maintenance solutions 4 - 5

1 Mobdock technology 6

2 Underwater repair services 7 - 13

3 Underwater maintenance services 14 - 17

4 Underwater welding and construction 18

5 Ecospeed for offshore units 19

without disruption, eliminating the

loss of time, production and income

that drydocking entails, as well as

saving the enormous expense of dry-

docking itself.

All the projects we undertake are en-

gineered and carried out in close co-

operation with the customer and any

third party suppliers. They begin with

evaluating the feasibility of an under-

water repair, continue through design

and construction of customized equip-

ment and go all the way through to

successful execution of the repair or

Hydrex offers turnkey under-water repair solutions to

owners of offshore related unitswherever and whenever they areneeded. Hydrex’s large and multi-disciplinary team will help you findthe best solution for any problemencountered with your vessel oroffshore unit below the water line.We will immediately mobilize ourdiver/technicians to any locationaround the globe to carry out neces-sary repair work without the needto drydock.

At Hydrex, we have a long and suc-

cessful track record of performing

complex permanent underwater re-

pairs to thrusters, propellers, rudders,

stern tube seals and damaged or corro-

ded hulls. In fact we pioneered most

of these more complex operations

which once used to require drydocking

but can now be carried out with the

vessel or unit afloat. By creating dry-

dock-like conditions around the af-

fected area, our diver/technicians can

carry out these operations on vessels

in port or at anchor. This permits nor-

mal commercial activities to continue

Turnkey underwater repair

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Damage

Customer Communication Workstation Setup

Problem Solved

Job Estimation

Contact

replacement and subsequent follow-

up. We take on, organize and execute

the entire job, start to finish, relieving

the customer of all the hassle of coor-

dination, planning and supervision.

All Hydrex diver/technicians are

trained and qualified to perform the

full range of required class-approved

repair procedures in even the harshest

conditions. We have found that an

effective, competent team is the only

way to consistently achieve a high

quality result.

Through an ever-expanding, world-

wide network of offices, Hydrex can

provide these start to finish solutions

economically at any location. Head-

quartered in the Belgian port of

Antwerp, we have offices in Tampa

(U.S.A), Algeciras (Spain), Mumbai

and Visakhapatnam (India), and Port

Gentil (Gabon). And the list is grow-

ing as the demand for cost-effective

localized services increases.

All Hydrex offices have fully opera-

tional fast response centers where an

extensive range of state-of-the-art

equipment is available at all times

for immediate deployment with our

skilled diver/technician teams to

wherever they are needed.

If you would like to learn more about

the Hydrex services for the offshore

industry, please visit our website

(www.hydrex.be) or call us 24/7 with

your underwater repair needs, routine

or emergency. Our technical depart-

ment is ready to create a tailor-made

solution for your specific need.

and maintenance solutions

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Customer Review

Back in Business

Underwater Preparation Operation

Engineering

Logistics

and enabling them to reinstall the pro-

peller blades of an overhauled thruster

inside the thruster tunnel after the unit

has been secured. They can also repla-

ce the blades or seals and perform

repair work on a specific part without

removing the unit.

In 2002 the flexible mobdock was

further developed so that a similar

dry underwater working environment

could be created around a stern tube

seal assembly to facilitate repair work

on the assembly and enable the re-

placement of damaged seals on site.

This technique has since been refined

and in the last few years Hydrex

diver/technicians have used the flexi-

ble mobdock technique for both bow

thruster and stern tube seal repairs on

numerous occasions during operations

around the world, resulting in winning

the prestigious Ship Repair and

Conversion Award at Lloyd’s List

Global Awards 2009.

As early as 1979 Hydrex was thefirst company ever to use a

prefabricated cofferdam, namely onm/v Lunar Venture and already in1983 the technology was used toperform inserts repairs in doublebottom tanks. The company hasadvanced this concept extensivelyover the last 30 years, along with the technology to ensure that fast,professional and high quality workcan be done on site and even whilecontinuing operations.

For its innovative work in this field

Hydrex has won the 2002 Lloyds List

SMM Award category of "Innovation

in Naval Shipbuilding and Marine

Technology". At the time of the award

these techniques were applied mainly

to the repair and replacement of bow

thrusters. Using steel mobdocks to

seal off the thruster tunnel, with an

access shaft protruding above the

water, work teams accessed the tunnel

and from there could work on the

thruster in complete safety.

Hydrex has since then developed this

technology further using lightweight

flexible mobdocks. These modernized

mobdocks, which are designed to be

easily transported around the world,

are used to close off the thruster tunnel

on both sides, allowing divers to work

in a dry environment around the unit

Mobdock used for hull repairs on an offshore unit.

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1. Mobdock technology

Class accepted flexible mobdocktechnique.

Tailor-made mobdocks are designed according to the customer’s need.

In-water thrusterremoval, renovation and replacement

Hydrex has developed the technology

to repair and replace a variety of

thruster types on site.

Thrusters are obviously a vital and

integral part of most vessels and espe-

cially so to many offshore units that

remain in position through DP or other

means. To go off-hire for repairs cau-

ses serious disruption to an offshore

operation resulting in a significant

loss of time and production. Mobdock

technology is the solution to this.

Azimuth thrusters

A Hydrex diver/technician team mobi-

lized to an offshore crane barge statio-

ned at its service base in Gabon to

Mobdocks in use

Our services facilitate anyowner or vessel manager to

control, predict and more easilydeal with unexpected problemsrelating to the in-water functioningof the vessel.

The complete service consists of peri-

odic monitoring throughout the year

by technical diving teams who

inspect, assess, advise and carry out

actions that need to be taken.

Considered preventive action can be

far more effective and save significant

time and money avoiding break-

downs.

The alternative service offered, while

the vessel is still on site or at sea, is

the immediate repair or replacement

of non-functional underwater equip-

ment (thrusters, stern tube seals etc.),

impact and corrosion repair, hull clea-

ning and one-off inspections. These

projects are managed from concep-

tion, design and construction of equip-

ment all the way through to repair or

replacement as needed. The scope and

effectiveness of these services is best

illustrated by example.

2.1 Thruster services

Removal of 40-ton swing-up azimuth thruster.

Hoisting the mobdock into position for in-water use.

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2. Underwater repair services

room and sealed it off. Next they

removed the mobdock, lowered the

thruster unit onto a special support

cradle under the work barge and

brought it onboard the barge.

Subsequently Hydrex engineers re-

moved the steering gear from the old

thruster unit and installed it on the

spare unit that had also been brought

onto the barge. This was done under

replace one of the vessel’s 40-ton

swing-up azimuth thrusters with the

spare.

The operation had to be carried out in

a very short timeframe because the

crane barge was scheduled to leave for

an operation in Nigeria. All repairs

and other servicing work needed to

be carried out before the start of this

operation. For this reason going to

drydock was not an option as the near-

est suitable location was South Africa

and this would have taken the repairs

far beyond the available timeframe.

Hydrex had carried out a similar oper-

ation on this vessel on two occasions.

Five years ago when the first azimuth

thruster was replaced, a large mob-

dock (measuring 9 x 6 x 2 meters and

weighing over 25 tons by itself) was

constructed under Hydrex supervision

in Belgium and transported to Gabon.

There it was stored after the repair

to be used at short notice whenever

future repairs were required on

thrusters. This allowed for a very fast

mobilization and thruster replacement

on the next two occasions.

To allow the Hydrex diver/technicians

to work on the water sensitive parts of

the azimuth thruster the tailor-made

mobdock was installed around the

retracted thruster and all water was

pumped out of it to create a dry envi-

ronment underwater. The team then

disconnected the unit from the engine

Construction of mobdock used to remove azimuth thruster.

Lowering the thruster onto underwater platform.

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the supervision of a representative of

the manufacturer. The old thruster was

then brought to shore for transporta-

tion to the workshop where it was

overhauled, so that the owners could

store it to use as a spare during future

operations.

Meanwhile the team installed the new

thruster into the crane barge following

the reverse procedure. Finally they

successfully carried out commis-

sioning and testing. This concluded

the replacement well before the start

of the barge’s next operation and

presented a major saving in time and

money for the owner as he did not

have to take the offshore unit off hire

to go to drydock.

Positioning mobdock underwater.

Fixed tunnel thrusters

Fixed tunnel thrusters can be worked

on by sealing off both ends of the

thruster tunnel. The thruster is then

serviced, removed or replaced as

required. This is done by constructing

two mobdocks that seal each end of

the thruster tunnel, so creating a dry

environment within. It is possible to

either have solid mobdocks with an

access funnel between the thruster

tunnel and the surface (in this way

non-diving technicians can enter) or

to have diver/technicians access the

tunnel underwater using a flexible

mobdock system. As with other

thruster types, propeller blades and

seals can also be repaired or replaced

within the mobdock environment.

As an example of preventative engin-

eering, a permanent double mobdock

system has been constructed and is

kept on-board an offshore unit to be

used at short notice, any time that

repairs are required.

Overhauled azimuth thruster lowered back into the water.

Permanent double mobdock system.

Hydrex diver/technician guiding azimuth thruster during removal.

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beneath the floater. The mobdock is

around 10 meters in diameter with a

number of separated ballast/buoyancy

tanks that control weight by manoeuvr-

ing under water. Once the mobdock is

Retractable thrusters

One of the largest crane and pipe

laying vessels in the world is the

Saipem 7000, a massive structure 200

meters long, 90 meters wide and with

an operational draft of 40 meters.

This semi-submersible crane vessel is

used to install offshore production

platforms and other heavy structures

in the open seas.

As part of its regular servicing sche-

dule, the Saipem 7000 needs work

carried out on its thrusters to replace

or overhaul a large number of valves.

The Saipem has retractable thrusters

located in its floater. When in shallow

water, such as in port, the thruster is

retracted into the thruster container

and housed in a compartment within

the floater itself.

Using a special circular mobdock the

compartment can be sealed off from

fully secured, the water is evacuated

from the thruster garage and then

inspections and maintenance can take

place on the thruster from inside the

floater.

Heavy-lift semi-submersible crane vessel stationed in Cartagena for maintenance.

Final preparations before placement of circular mobdock.

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from the interior of the FPSO and

reduced to small pieces that could be

carried away. Precision engineering

was required to cut out new inserts to

the correct size and also to cut away

internal support structures that held

the old damaged plating in place or

blocked access. The new insert was

welded in place, as was a renewed

support structure along with addi-

tional strengthening work where

necessary. The permanent repair being

complete for this area, the mobdock

was removed. This procedure was

repeated at each damaged area until

a total of 60 m2 of corroded or dam-

aged steel bottom plating had been

replaced.

Hull repairs are carried outusing mobdock technology

by sealing off the damaged sectionof the hull externally and thenremoving all water from within themobdock.

When extensive corrosion damage

had to be repaired on the hull of an

FPSO in Malabo, West Africa, Hydrex

used a tailor-made cofferdam to carry

out permanent repairs while the FPSO

remained in production.

After the cofferdam had been installed

over the first part of the damaged area,

the corroded section was cut away

Mobdock used for sealing off damaged areas of flat bottom section underwater.

Final modifications on mobdock before use.

Hydrex diver lowered with mobdock.

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2.2 Hull repairs

The replacement of stern tubeand various other types of

seals, including lip-type and face-type are completed both under-water and on site.

Prior to the flexible mobdock tech-

nology developed by Hydrex, it was

necessary to go into drydock for this

operation. Now, flexible mobdocks

are adaptable to all kinds of seal

assemblies. The technology for seal

replacements underwater has been

developed by Hydrex and is done

in cooperation with top seal manu-

facturers.

Flexible mobock used for underwater seal repairs.

Diver within flexible mobdock.

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2.3 Seal repairs

Using mobdock technology a dryworkspace is created under-

water alongside or over the areawhere the equipment or apparatusneeds replacing. In the case ofcathodic protection systems, theentire surface around the anode anddielectric shield is sealed off with a mobdock. The dry-atmosphericworkspace thus established allowshull surface preparation, renewal of the dielectric shield and replace-ment of the anode.

Replacement of the just the anodes,

cathodic or sacrificial, can be per-

formed in wet conditions without the

use of a mobdock.

Completed work with new anode and protective coating.

Mobdock for sealing area around anodes.

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2.4 Cathodic protection

repair or replacement and subsequent

follow-up.

also reduces drag and weight on the

unit and facilitates any needed full

scale inspection.

Preventive and protective mainte-

nance services can also be provided.

These 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 pre-

ventive engineering and scheduled

maintenance, work delays can be

eliminated or reduced significantly.

All projects are engineered and car-

ried out by Hydrex in close coopera-

tion with the customer, starting from

the design and construction of equip-

ment all the way through to the actual

Drilling vessel serviced in Gulf of Mexico.

Hydrex is capable of carryingout high quality and fast

underwater inspection and cleaningoperations or any other maintenan-ce work on offshore units. A Hydrexdiver/technician team can be onlocation and ready to service offsho-re units or offshore related vesselswithin days.

By taking advantage of Hydrex’s

in-house designed range of cleaning

units, all types of fouling can be re-

moved from any type of offshore

structure.

This offers owners big savings in fuel

when moving their unit from one loca-

tion to another which also means

reduced GHG and other emissions. It

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Underwater hull cleaning of drillingvessel in Gulf of Mexico.

3.Underwater maintenance services

The primary purpose of classifi-cation societies is to ensure the

structural and mechanical integrityof ships and marine structures fortheir intended purpose.

Hydrex takes this seriously and main-

tains close links with classification

societies both for maintaining certifi-

cation and for on-the-job application.

Our diving teams carry out detailed

video, photographic and NDT inspec-

tions as needed. Ultra-sonic equip-

ment is used for thickness measure-

ments, coating inspections, weld

inspections and weld defect detection.

Systems are available for above water

as well as underwater use.

On board monitoring during inspection.

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Hydrex has certified divers at its disposal, ready to perform all types of offshore inspections.

3.1 Inspection services

easier to clean. Even thick layers of

hard marine growth of more than ten

inches can be removed by the Hydrex

underwater cleaning units.

Fully equipped and operational,all Hydrex offices are ready to

mobilize immediately to carry outhigh quality and fast underwatercleaning operations on offshoreunits 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 off-

shore 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

Dive support vessel with Hydrex equipment approaching drilling vessel.

The twin head underwater cleaning unit is designed for cleaning tubular pipes,bracings and legs of offshore platforms.

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3.2 Underwater hull cleaning of offshore units

By removing all fouling from an off-

shore unit its weight is reduced and

the available deck capacity is increa-

sed. A cleaning operation also facili-

tates any needed visual inspection or

non-destructive testing. This allows

owners to be in total control of their

unit’s hull condition.

Examples of cleaning work carried

out with the Hydrex underwater clea-

ning units include the removal of a

thick layer of barnacles and mussels

from a construction support vessel in

Houston and three drill ships in the

Gulf of Mexico owned by Transocean.

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In-house developed ship hull cleaning equipment used on drilling vessel.

Hydrex diver during underwater hull cleaning on offshore unit.

Thick layers of marine growth caneasily be removed with the Hydrex

underwater cleaning units.

welding such as the application of

electrodes, provision of qualified

divers and equipment, management of

underwater projects, technical sup-

port, as well as coordination and vali-

dation of work projects and procedu-

res with classification societies.

• Application and design advice

• Project management of wet welding

projects

• Coordination and validation of

welding procedures with classifica-

tion societies

• Qualified wet welding procedure

specifications (WPS)

• Provision of qualified wet welder

divers and supervisors

The wet welding services provid-ed by Hydrex are amongst the

most advanced and of the highestquality. Specialist teams are givenboth in-house and external trainingand have extensive underwaterexperience. Our procedures arecompleted according to the AWSD3.6 Specification for UnderwaterWelding, the most widely usedunderwater welding specificationand our work is always approved byindependent classification societies.

We have fast response centers at all

our offices from where teams can be

mobilized at short notice for work

anywhere in the world.

Our services cover all aspects of wet

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4.Underwater welding and construction

Hydrex diver/technicians are qualified to perform a full range of repair procedures.

addition, the application of Ecospeed

has a very low environmental impact,

not only because Ecospeed has a low

contents of Volatile Organic Com-

pounds but especially because only

one application is required throughout

the lifetime on the vessel or structure.

d. Maintenance benefits

Every existing coating will eventually

suffer from marine fouling. Ecospeed

has been especially designed for

underwater treatment. Cleanings on

Ecospeed continuously improve the

surface characteristics without dama-

ging the protective qualities nor

affecting the coating thickness.

Specially designed tools have been

developed for fast, efficient and opti-

mal underwater treatment. Experience

has shown that prolonged static expo-

sure on any coating will result in

heavy fouling but a single underwater

treatment on Ecospeed suffices to

remove all fouling effectively and

return the surface to its pristine condi-

tion.

Acoating that claims to be suita-ble for offshore structures

should satisfy several conditions.This coating has to offer long-termprotection from corrosion and bio-fouling. An environmentally safesolution is also preferred. In addi-tion, the hull should always keep itsoptimum condition by on site main-tenance only.

In this respect, Hydrex has introduced

a coating concept named Ecospeed:

a durable hull paint which requires

only a single application and which is

specially designed for underwater

maintenance without damaging the

protective coating.

a. Durable protection against corrosion

Ecospeed demonstrates excellent anti-

corrosive properties. Diffusion of

watery solutions, including very ag-

gressive chloride ions in acidic solu-

tions, has no effect on Ecospeed

immersed in seawater. Based on expe-

rience with similar coating concepts

used in the offshore industry, Eco-

speed comes with a guaranteed corro-

sion protection of ten years. The ex-

pectations are that Ecospeed will last

25 years or the typical lifetime of a

vessel or offshore structure. Ecospeed

is a pre-qualified coating system in

accordance with NORSOK standard

M-501, Rev.5, June 2004.

b. Durable protection against bio-fouling

Ecospeed discerns of other coatings

by its impermeability for fouling

organisms. Regular underwater clean-

ings will effectively remove all foul-

ing organisms and improve the sur-

face characteristics.

c. Environmental benefits

Ecospeed demonstrates remarkable

environmental benefits that have little

or no negative or damaging effects to

its surroundings. Ecospeed is totally

free of biocides and experiments in

collaboration with the Dutch Ministry

of Infrastructure and the Environment

have shown that there is no release of

toxins during the curing process and

during on site treatment such as an

underwater polishing or cleaning. In

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5. Ecospeed for offshore units

www.hydrex.be

Headquarters Hydrex N.V. - AntwerpPhone: + 32 3 213 5300 (24/7)E-mail: h y d r e x @ h y d r e x . b e

Hydrex Spain - AlgecirasPhone: + 34 (956) 675 049 (24/7)E-mail: i n f o @ h y d r e x . e s

Hydrex LLC - Tampa, U.S.A.Phone: + 1 727 443 3900 (24/7)E-mail: info@hydrex.us

Hydrex West Africa – Port Gentil, GabonPhone: + 241 04 16 49 48 (24/7)E-mail: w e s t a f r i c a @ h y d r e x . b e

Hydrex India - MumbaiPhone: + 91 222 2046 988 (24/7)E-mail: m u m b a i @ h y d r e x . b e

Hydrex India -VishakhaptnamPhone: + 91 891 2711 863 (24/7)E-mail: vishakhapatnam@hydrex.be

Oil and gasTurnkey underwater repair and

maintenance solutions