surveying ju on location 649

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Surveying Jack-upson Location

Presented by: Svein FlogelandProduct Manager, Offshore Class

DNV Technical seminar on Mobile Offshore UnitsMumbai, February 15th 2008



Version Slide 214 February 2008

Why Renewals on Location

Owners wish to commence survey and complete in

shipyard- This allows the owner to know in advance if repairs are required

and cuts down on shipyard time

Owner has experienced delays in well programme andwants to carry out renewal on location

Owner wants flexibility to secure long term contract




Rule References

Intermediate and renewal surveys should be carried out inSheltered Waters. OSS-101 Ch3. Sec.2 C100

OSS-101 Ch.3 Sec. 2 D215 states that unit shall be dry docked at3rd renewal survey and subsequent renewal surveys, UNLESSacceptable equivalent alternatives are agreed.

Ch. 3 Sec.2 D300 states:

D 300 Alternative survey

301 Renewal surveys may be carried out on location without

interrupting the function of the unit, provided that they are

based on approved procedures outlined in a maintenance system

and survey arrangement.




Rule References Cont’d

See also Ch.2 Sec.2 G for matters that will be taken into consideration or

acceptance of surveys on location.

302 Provisions regarding fatigue safety factors and corrosion protection

shall be in accordance with the following requirements:

- DNV-OS-C104 Appendix A for self-elevating units.





G. Preparation for Surveys and Inspections on Location

G 100 General

101 It is advised that operational survey and inspection

aspects are taken into consideration at the design andconstruction stages.

The following matters will be taken into consideration foracceptance of surveys to be carried out on location:





arrangement for underwater inspection of Legs andspudcans

propellers, thrusters, rudders and openings affectingseaworthiness (for self propelled units)

accessibility of all tanks and spaces for inspection

corrosion protection of Legs and spudcans

testing facilities of all important machinery.




General Requirements for Surveys

E. Special Provisions for Hull Surveys

E 100 General

101 The owner shall provide the necessary facilities for a safe executionof the survey.

102 Tanks and spaces shall be safe for access, i.e. gas freed, ventilated,

etc.

103 Tanks and spaces shall be sufficiently illuminated, clean and free

from water, scale, dirt, oil residues, etc. to reveal significant corrosion,

deformation, fractures, damage or other structural deterioration.

Cleanliness is particularly important for areas which are subject tothickness measurement.




General Requirements for Surveys

E 200 Access to structures

201 For overall examination, means shall be provided to enable the

surveyor to examine the structure in a safe and practical way.

202 For close-up examination, one or more of the following means for

access, acceptable to the surveyor, shall be provided:

- permanent staging and passages through structures

- temporary staging and passages through structures

- lifts and moveable platforms- other equivalent means.




Flag States

MODU Code 1.6.2.5 …An Administration may allowunderwater inspections in lieu of a drydock survey providedthat they are satisfied that such an inspection is equivalent toa drydock survey

Load Line Convention…Sea valves to be opened up forinspection

SOLAS…..Safety Contruction renewal includes sea valvesand attachment to shell

IMO Res 948…4.6.6.2..renewal survey (bottom) should becarried out in dock. . When vessels reaches 15 years of agespecial consideration should be given before carrying outIntermediate surveys afloat. For Tankers Dry Docking is

mandatory.




Bottom survey for a Jack Up includes:

- External surfaces of the upper hull or platform,

spudcans, mat, underwater areas of legs,together with their connections.

- After Special Survey No. 2, the condition of theinternal structure of the mat or spudcans. Legconnections to mat and spudcans are to be

examined




Requirements for units intended to stay onlocation for prolonged periods

For units intended to stay on location for prolonged periods,(greater than 5 years), there is an appendixwhich must befollowed:

- DNV-OS-C104 Appendix A for self-elevating units.

3 main elements to consider for units ‘permanently’ onlocation

- Fatigue

- Corrosion Protection

- Inspection and Maintenance





FATIGUE

Design Fatigue Factors (DFF) are introduced inOSS-C101 as Safety Factors

The DFF applied to the structural details depend on

accessibility for Inspection and Repair

After application of DFF unit should demonstratesufficient fatigue life for area of operation for

duration of project





CORROSION PROTECTION

Maintenance programme required taking into account no DryDocking is planned





Inspection and Maintenance

Should be able to carry out Inspections without interruptionto the function of the unit

The following needs to be considered for Jack-up:

Arrangements and methods for survey of Hull, Legs and spudcans

Corrosion Protection Underwater Cleaning Facilities (inspection and drag)



Practical Planningand Execution




HSE

Special considerations offshore

- Enclosed spaces

- Overhead work

- Inspection and operation simultaneously

- Work permits

- Safe job analysis

Transport in sheltered waters

- Taxi boat




Planning

Establish a project team and involve DNV on anearly stage

4th Annual Survey may be a commencement for

Renewal Survey.

- Identify due items

- Identify what can be done offshore

- Identify surveys and tests that are due also after

renewal survey. Items that are better to do inadvance and as part of a plan:

- over load tests of davits and other lifting

equipment




Planning

equipment that requires large resources fordismantling

Inspection plan/program should be established alsofor items NOT covered by IIP and Machinery PMS

Planning = Predictability!

KICK-OFF MEETING




Project Organisation - DNV

Project group:

- Project Responsible

- Project Manager

- Project Team Members (general + specialists)- Co-operation with local units (if applicable)

Project Plan established (copy to owner)

Detailed Daily log and punch lists




Project Organization - Owner

We see large variations….

- Dedicated inspection teams carry out overhaul and

inspections – not part of offshore crew- Overhaul and inspections as part of “normal operation” –

carried out by offshore crew

Our Recommendations:

- Owner should establish project team early

- PROJECT MANAGER and DICIPLINE LEADERS- Utilize personnel with experience from previous projects

- Continuity!




Communication

Kick off meeting

- Class

- Yard- Sub-suppliers

Establish and clarify:

- Scope of work – Requirements

- How to do?

- Acceptance criteria

- Timing




Communication

- Communication lines

- DNV presence

- Qualification of personnel

- Reporting (lines & formats)

- Approval of sub-suppliers (e.g. CVI/NDT, UTM,Bottom, Radio, Lifesaving & fire ext. eq)

GOAL: ENSURE THAT EVERYBODY HAVE ACOMMON UNDERSTANDING PRIOR TO THE

PROJECT START




Documentation

PM Systems – Approved/not approved by DNV

It is our experience that owners very often want us to accept PMjobs signed out/crediting by owner/crew (all disciplines)

Priority should be given to update PM systems during planning andafter renewal surveys. During reviews we often find errors such as;

- Job descriptions and requirements are incorrect, not matching class

requirements- Intervals incorrect

- Corrective jobs handling

- Lack of certification requirements when generating Purchase Orders

Above may not be a requirement but will form a very good basis forfuture annual and renewal surveys

- Goal: Continuous improvement




Documentation

Availablility of original equipment documentation:

Product Certificates/COC

Databook

User Manuals

Areas of special concern:

DRILLING EQUIPMENT CRANES

Initial problem:

In-house tidiness – New building documentation

Incorrect purchase orders when ordering new equipment – Lack of certification

Incorrect purchase orders for overhaul of equipment at sub-suppliers




Items ”tricky” to carry out offshore?

Underwater survey (IS + RS)

Tailshaft survey (if fitted)

spudcans

Light Weight Inspection (draft readings)

Not possible if unit on location, How Long before we do next one? How to control

Overload test of cranes, winches & davits

Launching and release of life boats

Drill Equipment – overhaul and down time (BOP?) DRILL Class only

NDT&CVI in areas requiring climbers




Underwater Survey

Bottom shell plating

Jack-up legs – on location or at rig move

Spudcans, Spudcan to leg connection

Marine growth and extent of cleaning for both CVIand NDT

Use of divers and ROV – weather conditions




How do we survey this?




Continuous Class

The complete scope for a 5-yearly survey carriedout during a 5 year period

Resulting in a reduced scope during renewalsurvey.

PM system and documentation important

- Continuous Machinery Planned Maintenance – Well known

- BOP

- Cranes

- HP Manifolds and piping systems

surveying ju on location 649

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