Guidance on DNV's DRILL notation

<strong>Guidance</strong> on DNV’s DRILL notationOffshore Technical <strong>Guidance</strong> OTG-07, September 2012

OFFSHORE TECHNICAL GUIDANCE1 Introduction ............................................................................................................................................... 21.1 Introduction ...................................................................................................................................... 21.2 Objective ........................................................................................................................................... 21.3 Scope ................................................................................................................................................. 21.4 References ......................................................................................................................................... 31.5 Definitions and abbreviations ........................................................................................................... 31.6 Structure of document ...................................................................................................................... 52 Basic principles of class .............................................................................................................................. 62.1 Role and limitations of classification ................................................................................................. 62.2 Class in operation .............................................................................................................................. 62.3 System and equipment certification ................................................................................................. 82.4 Relationship with other Regulatory Schemes ................................................................................... 93 Survey execution ...................................................................................................................................... 103.1 Introduction .................................................................................................................................... 103.2 The survey process .......................................................................................................................... 103.3 System inspection and testing ........................................................................................................ 134 Handling of certified equipment .............................................................................................................. 324.1 Equipment repairs and overhauls ................................................................................................... 324.2 Certification of temporary equipment ............................................................................................ 344.3 Documentation ............................................................................................................................... 35DET NORSKE VERITASPage 1OTG-07

OFFSHORE TECHNICAL GUIDANCE1 INTRODUCTION1.1 INTRODUCTIONThe Offshore Service Specification DNV-OSS-101 “RULES FOR CLASSIFICATION OF OFFSHORE DRILLING ANDSUPPORT UNITS” contains DNV’s technical requirements and procedures for obtaining and retainingClassification for Offshore Drilling and Support Units. It includes a listing of the applicable technical referencesto be applied for classification.The Offshore Standard DNV-OS-E101 “DRILLING PLANT” contains criteria, technical requirements and guidanceon design, construction, commissioning and testing of drilling facilities, well intervention facilities andassociated equipment. Units meeting this standard may be awarded the Additional Class Notation DRILL.The technical and procedural requirements of the DRILL notation have a clear positive effect on safety of theunit and its drilling equipment, while at the same time ensuring clarity and transparency of the documentationof the systems within its scope.1.2 OBJECTIVEThe objective of this document is to increase the understanding of the DNV notation DRILL, its scope, objective,procedures and requirements in the operational phase of a drilling unit. This increased understanding willensure an efficient and effective follow up process to maximize the benefits of the notation.In simple terms:What, How, When and By Whom for compliance with DNV’s DRILL notationFigure 1 The objective of this document in simple termsThe readers of this document are foremost those who follow the procedures and requirements as described inOSS-101 and OS-E-101, specifically as they apply to the DRILL notation, for example:• Owners/personnel onshore and onboard responsible for regulatory compliance• Owners/ personnel onboard responsible for maintenance of equipment• Suppliers of drilling equipment (new and/or refurbished)• DNV surveyors• Other stakeholders (e.g. Flag, Coastal State Authorities)1.3 SCOPEThis document describes only the follow up of the DRILL notation in the operational phase of a unit. As such itexcludes specific guidance for activities during the building phase and up to delivery of the drilling unit.The document describes both the survey on board the unit and the relevant details and procedures for the recertificationof systems. It is to be used in conjunction with the above mentioned OSS-101 and OS-E101together, as a supplementary guidance document.This document does not describes the verification/ re-certification requirements and procedures as required bynational authorities 1 , although what is given here may be used to fulfil their requirements. .1 See also closing paragraphs of section 2.3DET NORSKE VERITASPage 2OTG-07

OFFSHORE TECHNICAL GUIDANCEFrom a technical perspective the scope of this document covers the following systems:• Drilling related structures• Well control systems• Heave compensation and tensioning systems• Hoisting and rotating systems• BOP and pipe handling systems• Bulk storage, drilling fluid circulation and mixing and cementing• Well testing and associated well control system• Other systems (winches, gear transmissions, manriding equipment).1.4 REFERENCESReference is made to the following DNV standards which are available for free download on the DNV websitewww.dnv.com:Offshore Service SpecificationDNV-OSS-101 Rules for Classification of Offshore Drilling and Support UnitsOffshore StandardsDNV-OS-A101 Safety Principles and ArrangementsDNV-OS-B101 Metallic MaterialsDNV-OS-C401 Fabrication and Testing of Offshore StructuresDNV-OS-D101 Marine and Machinery Systems and EquipmentDNV-OS-D201 Electrical InstallationsDNV-OS-D202 Automation, Safety, and Telecommunication SystemsDNV-OS-D301 Fire ProtectionDNV-OS-E101 Drilling PlantRecommended PracticesDNV-RP-A201 Plan Approval Documentation Types – DefinitionsDNV-RP-E101 Recertification of Well Control EquipmentDNV-RP-E102 Recertification of Blowout Preventers and Well Control Equipment for the US Outer ContinentalShelfIn addition relevant normative references can be found in Ch. 1 Sec. 1 of both OSS-101 and OS-E1011.5 DEFINITIONS AND ABBREVIATIONSDefinitionsBody testMaintenance: Pressure test of the equipment’s press envelope: General work on the equipment typically carried out offshore and usually by the unitcrewDET NORSKE VERITASPage 3OTG-07

OFFSHORE TECHNICAL GUIDANCEPerformance testPressure testOverhaul: Testing of the intended functioning of a component. Low pressure as well as ratedworking pressure is required. Operators to be tested as well as the main function itself.: Test, usually hydrostatic but may involve other fluids or gas, to test pressures as per therelevant standards.: Process of restoring and maintaining an equipment, machine, or system in a serviceablecondition. Overhaul involves (1) partial or complete disassembly of the item, (2)inspection to detect damaged, defective, or worn parts, (3) repair or replacement ofsuch parts, and (4) reassembly, testing, and trial-run prior to returning the item to its fulloperating level. Overhaul does not involve modifications to the original design.Over-pressure test : also referred to as proof test. With the component completely assembled but notpainted, and internal mechanisms in open position as applicable, all outlets should beblanked off. The component should then be pressurized to a test pressure asdetermined by the relevant design code, or as specially agreed.RefurbishmentRe-manufacturing: See definition of overhaul: Total or partial dismantling and weld, repair and/or stress relieving heat treatment, e.g.after rewelding ring grooves, bores etc. of pressure containing components. Gates ingate valves, flaps in non-return valves, rams in ram type BOP's, annular preventer bagelements or other sealing elements that moves. Pressure energized sealing such as ringgaskets are not classed as dynamic seals.AbbreviationsCVI Close Visual InspectionDPIIIPLPIMPIMWPNDTPWHTUPSPSVROVIBOPWPDye Penetrant InspectionIn-service Inspection program. A DNV developed inspection plan containing the structural items to besurveyed to satisfy the requirements of main class, excluding any additional class notations (note forcolumn stabilized and self-elevating units only)Liquid Penetrant Inspection (also known as DPI)Magnetic Particle InspectionMaximum Work Pressure (maximum pressure for which item is designed)Non Destructive TestingPost Weld Heat TreatmentUninterrupted Power SupplyPressure Safety ValveRemote Operated VehicleInternal Blow Out PreventerWorking PressureOther definitions and abbreviations can be found in Ch. 1 Sec. 1 of both OSS-101 and OS-E101.DET NORSKE VERITASPage 4OTG-07

OFFSHORE TECHNICAL GUIDANCE1.6 STRUCTURE OF DOCUMENTTo increase a basic understanding of the role of class and as a foundation of the following chapters, thisdocument starts with an introduction to classification, highlighting the role of class and its limitations, thesurvey and the certification process.Chapter 3 thereafter, focuses on the survey execution. After a discussion on the followed process during thisexecution, paragraph 3.3 details the specific survey, test and documentation requirements for each specific(sub) system as inside the scope of DNV’s DRILL notation.Chapter 4 continues with handling of certified equipment, discussing in special equipment repairs andoverhauls, certification of temporary equipment and documentation.The document concludes with an Appendix containing a list of all equipment under a Category I equipmentscheme.DET NORSKE VERITASPage 5OTG-07

OFFSHORE TECHNICAL GUIDANCE2 BASIC PRINCIPLES OF CLASS2.1 ROLE AND LIMITATIONS OF CLASSIFICATIONWhat is classificationClassification is the definition of a set of requirements for vessels and systems together with an inspectionregime providing assurance that the requirements are met during the design and construction, and maintainedduring the operational life of a vessel or Mobile Offshore Unit (MOU).Relevant requirements for these are dependent on specific design and operational use. Classification isstructured accordingly and this is identified by notations. Besides identifying which set of requirements isapplied, these notations also differentiate between mandatory and voluntary requirements.For the mandatory part, DNV mandates that the requirements and our identified involvement is essential toensure a minimum safety and reliability of the asset, the lives of the personnel onboard and the environment.As such, the compliance to these is a prerequisite for operating under DNV class. This is an importantfoundation for the worldwide recognition classification has gained as representing an adequate level of safetyand quality 2 .The voluntary requirements are beyond the minimum safety and reliability of the asset; either extending thescope of DNV’s involvement or assuring higher safety, reliability level and/ or capability. Being voluntary, it isthe decision of the owner and his contract partners to follow these or not.What classification is notClassification does not relieve the owner in its responsibility for safe and reliable operations, nor hisresponsibility to maintain the vessel/MOU properly.In addition, classification is not a substitute for the client's own quality and safety control and related duties, orthe client's obligations to third parties, nor to relieve the client of any consequences of default.Even though there may be some overlap, classification does not ensure that national regulations are met. Thisapplies in particular for our mandatory notations aiming at a minimum safety and reliability worldwide. It isonly with certain additional voluntary notations and scope that 100% coverage may be achieved.Even with the application of these specific national notations, classification does not imply that the vessel isapproved by the relevant flag state or coastal shelf authorities. It is only after their acceptance andauthorization that DNV may issue the relevant certificates on their behalf.2.2 CLASS IN OPERATIONSurveysAll units in class are subject to periodical surveys in order to confirm that the hull, machinery, equipment andsystems remain in satisfactory condition and in compliance with Rules and other mandatory standards. Thesesurveys, by definition executed by a class surveyor, can be supported by the inspection results of 3 rd partycompanies or approved service suppliers.2 A second element for the recognition of class is the separation of roles between owner, responsible formaintenance and operation of the unit within its approved design limitations, and classification as independentverifier that the unit is maintained to a Class standard and operated within its approved design limitations.DET NORSKE VERITASPage 6OTG-07

OFFSHORE TECHNICAL GUIDANCEThe scope of the surveys is dependent on the vessel characteristics (i.e. vessel shape, its function, age andsystems on board), but also on the (selected) involvement of class. The last is identified by the class notationthe vessel caries. As a specific example for this guideline, we highlight that the drilling systems and equipmentare only included in the class survey scope if the vessel carries the DRILL-notation. On the other hand; if thevessel does not have the DRILL notation, the survey shall not cover the drilling systems and related equipment.The attending surveyor’s focus of attention on the drilling systems and equipment is on the “safety-related”and reliability aspects of the drilling systems and equipment. Such systems/equipment generally fall into one ofthe following two categories:• Safety related due to its functionality (e.g. well control equipment);This implies that failure to function as intended, has a direct effect on the unit’s ability to control,detect or mitigate against a hazardous situation.• Safety hazard can result as a consequence of an equipment failure (e.g. lifting appliances).For the DRILL notation, the following periodical surveys exist (including their interval between parentheses):• annual survey (interval of one year, with a window of +/- 3 months);• complete survey (interval of five years, with a window of -3/-0 months).A more detailed description of the execution of these surveys is given in Chapter 3.The above traditional surveys may be replaced by alternative survey arrangements. A common objective ofthese is to reduce down-time resulting from the normal survey schemes. In addition they may lead to improvedreliability and reductions in maintenance cost. The figure below gives a short introduction to the alternativearrangements.PMS-RCMThe Planned Maintenance System based on Reliability Centered Maintenance Methodology or PMSRCM surveyregime has been introduced in order to reduce down time and increase flexibility for owners who are using an RCMbased preventive maintenance system. The RCM approach will typically also lead to performance improvement,reductions in maintenance cost and improved reliability.PMS-RCM can be utilized for main class machinery and drilling equipment. The main scope for annual and renewalsurveys is to ensure that the maintenance program is complied with and that the owner is actively utilizing acontinuous improvement program in order to ensure that the maintenance system is continuously optimized.Offshore CMThe Offshore Continuous Monitoring (Offshore CM) survey arrangement allows the vessel owner to replacecalendar based overhauls with condition monitoring. This will reduce the need for down time due to intrusivesurveys. Generally a CM program will also have a significant contribution in ensuring higher regularity and reducedmaintenance cost. The survey arrangement is applicable to main class machinery and drilling machinery. It isnecessary to use an approved service provider for the condition monitoring.Figure 2 Introduction to alternative survey arrangementsConditions of Class and AuthorityIt is the responsibility of the Owner to ensure that the unit continues to meet the technical standards asdefined by the Rules, and it is the responsibility of DNV to verify this and in addition to communicate this statusto all relevant stakeholders. This separation of roles is an important foundation for the internationalrecognition of Class.DET NORSKE VERITASPage 7OTG-07

OFFSHORE TECHNICAL GUIDANCEThe above relationship requires good and transparent communication. In addition to the day-to-day dayoperational communications, two formal means of communication have been defined to communicate thestatus of a unit; Conditions of Class/Authority (CC, respectively CA, depending on the deviation as referred toby the Condition are part of Class or National Legislation) and Memorandum to Owner (MO).A detailed description of these can be found in DNV Offshore Service Specification-101, Ch. 1, Sec. 5. Figure 3highlights their structural differences.CC/ CA• deviation fromstandard• requires follow upMO• other suplemental info• no follow up requiredFigure 3 Differences between CC/CA and MOA CC/CA is formal documentation of a deviation from a technical standard found in the Rules or StatutoryRequirements, and requires formal follow up by the Owner. A MO, though formally issued, is used tocommunicate information to the Owner and does not require formal follow –up by the Owner.2.3 SYSTEM AND EQUIPMENT CERTIFICATIONThe purpose of system and equipment certification is to:1. defining minimum requirements for the design, material, construction, testing and commissioning;2. serve as a reference document in contractual matters between purchaser and contractor;3. serve as a guideline for designers, purchasers and contractors;4. specify procedures and requirements for drilling and well intervention facilities;5. Provide transparency of the system design and quality to involved stakeholders, e.g. charterer,authorities, public.Certification of certain drilling systems and equipment is mandatory for Class notation DRILL. Details of therequired certification process is given in OS-E101, Ch. 3, the systems involved are listed in Appendix AFigure 4 gives a schematic overview of a certification process’ basic steps. The follow up of each step in anactual component depends on a risk assessment including experience of the manufacturer on the componentunder certification, its quality control system, the complexity of the design etc.Special attention is drawing to the last box of the figure, ‘Certificate maintenance after delivery’. It is requiredthat certification is maintained after delivery of the vessel, during its life time. Note in this respect on therelation with objective number 5 on the beginning of this section. Chapter 4 discusses in detail howcertification should be handled after delivery, including implications of class transfers and new buildings with alimited class involvement.DET NORSKE VERITASPage 8OTG-07

OFFSHORE TECHNICAL GUIDANCE1. design approval, documented by a design verification report (DVR) or typeapproval certificate(for existing equipment review of certificates)2. pre-production meeting prior to the start of fabrication3. survey during fabrication, as applicable(survey scope iaw agreed Inspection and test plan)4. witness final functional, pressure and load tests, as applicable5. review of fabrication records6. Certificate maintenance after deliveryFigure 4 Overview of certification process’ basic stepsClassification has no requirement for “re-certification” of equipment. The correct functioning and maintenanceof the equipment is verified during the renewal survey and by DNV’s involvement during equipment repairsand overhauls. The resulting survey reports document that the certified equipment is maintained andfunctions according prescribed standards.However, it is recognized that national legislation may require a (5-yearly) re-certification. DNV may providethe certification services in order to comply with such legislation in addition to its class services.2.4 RELATIONSHIP WITH OTHER REGULATORY SCHEMESThis document only describes the relevant procedures as follows from classification. For more information onre-certification we refer to DNV-RP-E101, Recertification of Well Control Equipment, and DNV-RP-E102,Recertification of Blowout Preventers and Well Control Equipment for the US Outer Continental Shelf.DET NORSKE VERITASPage 9OTG-07

OFFSHORE TECHNICAL GUIDANCE3 SURVEY EXECUTION3.1 INTRODUCTIONThis chapter describes the execution of the survey to drilling systems and equipment as covered by the DRILLnotation. It consists of two parts. The first describes the survey process and scope, both for the annual andcomplete periodical surveys, and the preparations required for an efficient execution of the survey.The second part describes the inspections and tests as part of the surveys, per specific system.3.2 THE SURVEY PROCESSPlanningThe owner is encouraged to communicate with its local DNV station at least 6 months prior to the 4th annualanniversary date, to fully evaluate and understand the upcoming survey.It should be understood the owner can commence the survey 1 year in advance of its anniversary date andmuch of the survey can be conducted during operations. Also it should be understood selected equipment mayhave been recently overhauled or replaced; OEM or independent inspections could become a factor to reducesome inspection.It is underlined that the above approach supports a common evaluation of the unit and eliminates unnecessarydown time.PreparationFor a successful and efficient implementation of a DRILL survey, it is important (and DNV expects) that ownerand personnel on board prepares itself. In addition, the safety and health of environmental aspects of thesurvey are under responsibility of the owner and should be ensured as well. This section lists the relevantpoints of attentions and instructions.Relevant safety preparations are given in Figure 5. In addition should equipment and structures be cleaned asnecessary to facilitate proper inspection as listed in Figure 6.Safety is the owner's responsibility.Inform on vessel specific safety by a vessel specific safety trainingAll spaces shall be made safe for access i.e. gas freed, ventilated and illuminated. Spaces shall be prepared for the surveyorto examine the structure in a safe and practical way. One or more of the following means for access, acceptable to thesurveyor shall be provided:• permanent staging and passages through structures• temporary staging and passages through structures• lifts and moveable platforms• portable ladders• other equivalent meansEnsure safety of system inspections by:• lockout / tagout systems• decontamination (H2S potential)• blocking / bleeding of high pressuresFigure 5 Requirements for safetyDET NORSKE VERITASPage 10OTG-07

OFFSHORE TECHNICAL GUIDANCECleaning is the owner's responsibility.Spaces should be sufficiently clean and free from water, scale, dirt, oil residues etc. to reveal any corrosion, deformation,fractures, damage, or other structural deterioration. However structural areas where renewal already has been plannedfor, need only be cleaned and de-scaled to the extent necessary to determine the limits of the renewed areas.Figure 6 Requirements for cleaningMaintenance Records for all structure and equipment covered by the DRILL notation should be made available.Any required testing (e.g. alarms, shutdowns) will be indicated in a ‘Survey Preparation Note’ and agreed priorto the survey. Such testing should be properly planned in order to minimize both disruption of the drillingoperation and delays to the survey. See the figure below for a short introduction on the ‘Survey preparationnote’.What is it:A Survey preparation note is an automatically generated, vessel specific, checklist giving guidance ontesting and documentation requirements for equipment under survey.How to obtain: The note can be obtained using DNV Exchange. Under the ‘Vessel Home’ menu for a specific vessel, a‘Download Survey Preparation Note’ button can be found on the bottom of the page. More help,including an instructional video can be found in the help menu of DNV Exchange, using the searchterm ‘Preparation’.How to use:It is recommended that the Owner generates a Survey preparation note during the planning phase ofsurveys. The note assists the Owner and crew to prepare for efficient execution of the survey. If thesurvey is prepared in accordance with the notes, unnecessary delays may be avoided.Figure 7 Explanation on Survey Preparation NotesImportant to take into account during the preparation of the survey is the difference in nature of annual vs.complete surveys. Figure 8 highlights these differences.Annual•mostly visual inspection•review of records•drilling operationcontinues•on site•ad hoc - possible severalvisitsComplete•more intrusive•drilling operatiionsuspended•typical during upgrades/maintenance periods•well planned in advanceFigure 8 Main differences between annual and complete surveyThe executionOn arrival onboard, a kick-off meeting should be held between the surveyor and the crew, in order to discussand agree the scope and schedule for the survey. At that meeting, any equipment which is out of serviceshould be identified, as well as any ongoing operations which might conflict with the survey.DET NORSKE VERITASPage 11OTG-07

OFFSHORE TECHNICAL GUIDANCEThe execution of both annual and the complete survey consists of:a) a review of the unit’s records;b) equipment inspection;c) review of certificates.The figure below illustrates main elements of a survey and the difference in actual execution between annualand complete survey.Review ofrecordsANNUALRoutineinspections/testsand themaintenance/repair/overhaul records.COMPLETE PERIODICALMore thoroughSystemVisual, witness andreview maintenancerecordsOpening, testing, NDTReview ofcertificatesSpot checkTraceability of originalcertification/documentationFigure 9 Overview of main elemens of annual vs. complete periodical surveys. For a more detailed description on thereview of certificates, see Section 4.3.The thoroughness and stringency of the survey should depend upon the condition of the equipment (i.e. asrelated to failure of age) or the records of maintenance performed. Should any doubt arise as to themaintenance or the condition, further examination and testing should be conducted as considered necessary.Parts of the inspection can be executed by other 3 rd party companies as well. The relevant requirements forthese inspections are given the figure below.A DNV surveyor shall be onboard to the extent he or she finds necessary to control the process, when inspections by other3 rd party companies (e.g. NDE or thickness measurement) are done for class. Measurements which have not been carriedout in co-operation with DNV cannot be accepted. The 3 rd party company shall inform the owner accordingly. This appliesto all units where the inspection will make the basis for the surveyor's decisions during class surveys.The 3 rd part company shall have a suitable DNV approval (e.g. in line with DNV’s Approval Program 402B).The operator shall notify the DNV surveyor of any structural deficiencies, such as cracks, indents, buckling or abnormalmeasurements detected.There shall be a kick off meeting for the planning of NDE or thickness measurements, including Owners representative, 3 rdparty company and DNV. The meeting shall clarify initial scope of close-up examination and thickness measurements.Figure 10 Requirements for inspections by approved service suppliersDET NORSKE VERITASPage 12OTG-07

OFFSHORE TECHNICAL GUIDANCE3.3 SYSTEM INSPECTION AND TESTINGOverviewThe below diagram gives a schematic overview of the different drill equipment and components which are partof the annual and complete periodical survey and as such subject to inspections and test. In the subsequentparagraphs, the relevant inspections and tests are discussed for each item of equipment/ component in detail.Requirements presented for annual survey shall also be carried out during complete periodical survey.DET NORSKE VERITASPage 13OTG-07

OFFSHORE TECHNICAL GUIDANCEDrilling relatedstructuresWell control systemHeave compensationand tensioning systemsHoisting and rotatingsystemsBOP- and pipe handlingBulk storage, drillingfluid circulation andmixing and cementingWell testing andassociated well controlsystemOther systemsDrilling structureBOP stackHeavecompensationsystemHoistingequipmentDrawworks &Deadline anchor **Horizontal pipehandlingCementingFlare boomsWinchesDrill floorBOP controlsRiser tensionersystemRotating systemsTop drives &swivels incl. dollyVertical pipehandlingHP circulationpiping and valvesWell testingpackageLoose gearSubstructure *Diverter systemTravelling blockBOP, Xmas treeand riser overheador gantry craneKellycocks/IBOP/valvein drillstringPressure vesselsSupport structurefor drilling/welltesting equipment*Choke & kill systemCrown blockBOP and Xmas treetrolleyMud pumpsManridingLiftingarrangements forequipmentMarine risersystemMud pitsBulk storage* items are part of Main class, but follow up may be done during the DRILL survey** covers both conventional and cylinder based hoisting systemsDET NORSKE VERITAS OTG-07Page 14

OFFSHORE TECHNICAL GUIDANCEDrilling related structuresAnnualDrilling relatedstructuresComplete periodical• Visual inspection of primaryload path, including supports,foundations, anchorages andguides; checking for bent ordamaged members.Hammering test is acceptable.All bolts shall have asecondary securingarrangement;• NDT as deemed appropriateon weld attachments ofbottom of derrick “legs” to“feet pads”;• Review of records of theroutine checking of thetorqueing of the structuralbolting, all bolts should bechecked regularly;• The derrick should bechecked for loose items, andsecuring of items wich mayfall down, e.g. lightarmatures,snatch blocks, etc.Drilling structure• Confirm satisfactory fastening of derrick fixtures,special attention to fixation and support of heavyequipment;• Spot-check NDT on main structural components asdeemed appropriate;• Spot-check NDT on dismantled bolts and gaugethreads;• CVI, dimensional reports and NDT of padeyes,sheave blocks.• Refer to the IIP (In-serviceInspection Program) for theunit.Drill floor• Refer to the IIP for the unit.• Refer to the IIP for the unit(This area is often difficult toaccess and very dirty).Substructure• Refer to the IIP for the unit (This area is oftendifficult to access and very dirty);• Survey around moonpool structure.• Visual inspection of primaryload path for bent or damagedmembers;• Visual inspection of seafasteningarrangement.Support structurefor drilling/welltesting equipment• Spot-check NDT on main structural components asdeemed appropriate.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnualDrilling relatedstructuresComplete periodical• Visual inspection primaryload path members includinglifting eyes/pad eyes.Liftingarrangements forequipment• Spot-check NDT on main structural welds as deemedappropriate.• Load test as requiredWell control systemsAnnual Well control Complete periodical• Review of records ofmaintenance (e.g. pressuretest results, NDT reports,repair work);• Review records for functiontesting of the BOP using theaccumulators mounted on theBOP Stack;• Review records for functiontesting of the fail-safe valvesin the Choke & Kill linesmounted on the BOP.BOP stack*/General* incl. hydraulic hoses,shuttle valves, highpressure panels, etc.• Such major components will normally have the majoroverhauls carried out during the complete periodicalsurvey. Confirmation of recent major overhaul ofBOP components in presence of a DNV Surveyor tobe reviewed;• Complete function testing of the BOP-stack includingall preventers, connectors and fail-safe valves (usingthe accumulator system, not only the stack mountedaccumulators);• Leak/pressure test to demonstrate satisfactoryfunction of rams, annular elements, valve gates, C/Kconnections;• Testing should be carried out at low pressure (approx.200-300 psi) and then at max rated working pressure.(Note: For testing of the pipe rams and annularelement a suitable test tool should be used, suitablyanchored to the test stump);• MPI of all load bearing welds on the BOP guideframe;• Survey of BOP stack structural frame checkingevidence of excessive corrosion or damage.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnual Well control Complete periodicalSee “BOP stack*/ General”.BOP stack/ annularpreventer• Review initial certificate/ maintenance. History;• Visual survey:a) Disassemble for 100% visual inspectioninternally and externallyb) Verify markings to previous certificationc) Visually inspection of seals and packer/donutd) Visually inspection seal areas.• Non-destructive testing:a) MPI - all weldsb) MPI - bottom ring grooves, DPI if stainlesssteel inlayedc) MPI - all seal areas on body and other partsd) MPI – pistone) MPI - adapter ring/inner and outer cylinderheadsf) General hardness checks.• Dimensionally check:a) Bottom flange/hub thicknessb) Bottom ring groovesc) Through bored) Pistone) Adapter ring/ inner and outer cylinder heads.Note:The above dimensions to be verified to the originalmanufacturer’s dimensions and tolerances onthese. 3The maker’s dimensional information may often betried kept secret, but is often found available to therepair shops.• Pressure testing to maximum WP;• Weld repair (if required) see page 32.3 It is emphasized that DNV has no preference over OEM to non-OEM (see also section 4.1)DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnual Well control Complete periodicalSee “BOP stack*/ General”DET NORSKE VERITASBOP stack/ RAMpreventerAppendix A• Documentation:a) Review initial certificateb) Review of maintenance history• Visual survey:a) Disassemble for 100% visual inspectioninternally and externallyb) Verify markings to previous certificationc) Surface finish on connecting rods forpitting/scoresd) Ram cavities for wear/scores and localdamage in the sealing positione) Seal assembly preparations in bonnets for theconnecting rodsf) Grooves in rams for the packersg) Bonnet bolts and preparations in the body forthe boltsh) Shear ram blades• Non-Destructive testing:a) MPI - all weldsb) MPI - all ring grooves, DPI if stainless steelinlayedc) DPI - piston rods and cylinders (reject flakingplating)d) MPI of all ram sockets in the connecting rods(recommended onlye) MPI - piston rod buttonsf) MPI - ramsg) MPI - bonnet boltsh) Hardness test piston rod button (due to workhardening)• Dimensionally check:a) All flange/hub thicknessb) All ring groovesc) Thru-bored) Ram cavities (check for scoring in way ofram seals, i.e., at the top of the cavity)e) Ram back face to be checked for straight edgef) Racetrack seal facesg) Intermediate flanges seal groovesh) Ram change cylinder sealing ID on bonnetsand intermediate flangesi) Ram change cylinder seal bores on bonnetsand intermediate flanges.Note:The above dimensions to be verified to theoriginal manufacturer’s dimensions andtolerances on these.• Pressure testing see Table 1on page 33;• Weld repair (if required) see page 32.OTG-07

OFFSHORE TECHNICAL GUIDANCEAnnual Well control Complete periodicalSee “BOP stack*/ General”See “BOP stack*/ General”BOP stack/ ClampsBOP stack/Hydraulic wellheadconnector• Visual Inspection, Verify Markings to PreviousCertification;• MPI clamps & bolts (25%);• DPI of stainless steel ring gasket grooves ifapplicable;• Confirm correct washers fitted and/or nuts fitted;• Dimensionally check clamp.Note:Improperly torque tightened bolts or damagedthreads can reduce fatigue life of clamps, andpossibly lead to product failure• Visual survey;• NDE critical areas;• Dimensions control;• Pressure test primary and secondary openingsystems to rated working pressure;• Pressure test wellbore to rated working pressure.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnual Well control Complete periodical• Visual inspection;• Review records that theroutine function testing issystematically covering allthe primary and secondarycontrol systems (redundantcontrol panels, controlpods, flexible control hoses& the acoustictransportable panel);• Visual inspection of hosereelfor flexible controlhoses;• If electrical (i.e. multiplexsystem), then specialattention to purging of theslip ring including test ofshut down on loss of purge;• Review records of functiontest of the EDS, Deadmanand Autoshear Circuits.BOP controls• Confirm satisfactory operation and independenceof the pods (re API RP53 B.13) if necessary byretrieving one of the pods and working the BOPwith the other;• Leak/pressure testing to max. WP of installedhoses and piping;• Operate all functions from main BOP hydraulicunit and all remote locations;• Check flowrates and reaction times in accordancewith API RP 53;• Check alarms (visual and audible) for lowaccumulator pressure, low rig air pressure, lowmanifold pilot pressure, low fluid level andautostart/autostop of pumps, loss of power supply,low battery level and UPS alarms;• Check function in emergency shutdown situation;• Test of acoustic panel (if fitted)• Check calibration of manometers andthermometers;• Confirm safety valves (or temperature sensitivefuse plugs) on the accumulator nitrogen chargingside;• Check regular testing of the safety valves (PSVs)in the systems. It is the norm for the PSVs to beopened up for inspection and retested at max. 30months intervals;• Check operating of the regulator for the closingpressure in case of loss of rig air;• Internal survey, alt. thickness measurements, ofaccumulators;• Confirm pre-charge pressure of the accumulators(By completely draining them and witness suddenpressure drop when empty);• Confirm emergency power supply for remotepanel operation. (Normally, remote panels arepowered by 24V DC batteries continuously tricklecharged. Loss of charging will give alarm butallow uninterrupted operation by the batteries);• Visual control of accessible parts of mainumbilical hoses for external damages and unapprovedrepairs. (often found damaged);• Functional and Operational demonstration of bothControl Pods Emergency Circuits. To includeEDS (all levels), Deadman and Autoshearsequences according to design;• Function test of ROV hot stabs;• Capacity test of pump unit.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnual Well control Complete periodical• Visual survey (as far aspossible): verify markings/previous certication;• Review records that theroutine function testing issystematically coveringoperation from the main andremote control panels;• Review records that the valvesequence interlocks(overboard valve to openbefore closure of the diverterannular and mud systemvalves) are function tested;• Follow up of any occasionswhere the Diverter Systemhas been used (ref. additionalwall thickness checks in wayof the bends/ fittings/constrictions subject topotential erosion andprecautionary inspection ofpipe supports in way of thebends);Diverter system• Close up visual survey:;• Such major components will normally have theMajor Overhauls carried out during the Completeperiodical Survey;• Confirmation of recent Major Overhaul of maincomponents in presence of a DNV Surveyor to bereviewed;• Leak/pressure test to confirm tightness of seals.• Operate all functions from main and remotepanels.• Confirm valve sequence interlock (opening ofoverboard valve prior to closure of annular andmud system valves);• check wall thickness as appropriate ofbends/fittings/constrictions subject to potentialerosion and precautionary inspection of pipesupports particularly in way of the bends;• Verify response time.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnual Well control Complete periodical• Visual inspection: verifymarkings/ previouscertication;• Review records of satisfactoryfunctioning of the chokes(manual and remote);• Review records of the routinefunction testing for valvetightness (carried out fromboth sides, for those valves inthe system where flow ispossible from eitherdirection);• Confirm manifold gauges anddriller’s gauges correctly arecalibrated annualy;• Function test of theEmergency Circulation Pump(normally the diesel drivencementing unit), includingstarting of pump & thealignment/operation ofnecessary valves under a(simulated) Black-Shipcondition;• Visual control of accessibleparts of flexible hoses forexternal damages and unapprovedrepairs. (often founddamaged).• Visual inspection ofaccessible equipment;• Review records/indications ofextreme heave, sway/surge ofvessel during previousoperations (potential fordamage from “bottoming out”of the Telescopic Joint);• Review records of regulartesting of the emergency riserdisconnection operation fromthe main and remote controlpanels, including secondaryunlocking mechanism.Choke & Kill systemMarine riser system• Leak/Pressure test at low pressure (approx. 200-300 psi) and also at max. WP. If flow possible inboth directions, valves to be tested from bothdirections if it can see pressure from both sides;• Confirm operation of manual and remote chokes;• Review maintenance/overhaul records of theEmergency Mud Pump, with particular focus onthe starting arrangements;• check wall thickness checks in way of thebends/fittings/ constrictions subject to potentialerosion or corrosion and precautionary inspectionof pipe supports particularly in way of the bendsand restrictions;• Flexible Hoses: Special attention to be paid for anymanufacturer's recommendations for regularinspections & tests (ref. high temp/high pressurewells incidents in the late 80's). Disassembly forvisual survey and Dye Penetrant of Stainless Steelring-gasket grooves, MPI of flange/hub necks;• Pressure testing to max. WP of all HP piping andflexible hoses;• Close up visual survey all valve and hard piping.Opening up of some valves, review of records forthe remaining ones. Chokes to be opened up andvisually surveyed;• Calibration of manometers and thermometers;• CVI of all flexible hoses for external and internaldamages and un-approved repairs. (often founddamaged). Also to include booster hoses, hydraulic(conduit) hoses and LMRP (jumper) hoses;• Verification of correct certification (hosesinspected are often not in• Such major components will normally have themajor overhauls carried out during the Completeperiodical Survey. Note that DNV inspection canfollow usage based inspection periods.• Confirmation of recent major overhaul of categoryI components in presence of a DNV Surveyor tobe reviewed;• Visual inspection with buoyancy elementsremoved (i.e. stripping of riser joints);• Pressure test to max. WP (of choke, kill andbooster lines);• 100% NDT of the lugs for support ring for risertensioning system;• NDT of handling tools;• Confirmation of recent major overhaul oftelescopic joint and ball joint.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEHeave compensation and tensioning systemsAnnualHeave compensationand tensioningComplete periodical• Visual inspection;• Review records of regulartesting of the Pressure SafetyValves (PSVs) in the system(typically 30 month maximuminterval);• Review of records ofmaintenance (e.g. wires andsheaves, including “slip &cut” records);• Review records of regularcalibration of accumulatorpistons.• Visual inspection;• Review records of regulartesting of the PSVs in thesystem (typically found on theair compressors, accumulatorbottles, pressure vessels,control panels). It is the normfor the PSVs to be opened upfor inspection and retested atmax 30 month intervals;• Review of records ofmaintenance (e.g. wires andsheaves, including “slip &cut” records).HeavecompensationRiser tensioner• Pressure testing to max. WP of installed piping;• Stroking of tensioners to confirm free movement;• Confirm safety valve setting and review records ofregular opening up/overhauls;• Inspection of pressure vessels/accumulators (forinternal inspection, alternative methods may beapplied);• Inspect sheaves, alignment and free movement ofsheaves. Sheaves wear to be measured. (ConsiderNDT of sheave grooves and external welds onsheaves if found worn. Often cracks can be foundin casting, wire groove or weld attachments);• Consider load testing of retractable sheaves at fullextension, if deterioration noted;• Inspection of wires and associatedsecuring/clamping arrangements;• Confirm operation and safety features of anydedicated compressors or auxiliary machinery;• Confirm operation of main valve control andindicators (weight and pressure);• Anti-recoil valves, i.e. slingshot/Olmsted valves(test for proper functioning);• Check foundation fastening.• Pressure testing to max. WP of installed piping;• Stroking of tensioners to confirm free movement;• Confirm safety valve setting & review records ofregular opening up/overhauls;• Inspection of pressure vessels/accumulators (forinternal inspection, alternative methods may beapplied);• Inspect sheaves, alignment and free movement ofsheaves (sheaves wear to be measured);• Consider load testing of retractable sheaves at fullextension, if deterioration noted;• Satisfactory operation of hydraulic and pneumaticsystems to be confirmed;• Inspection of wires and associatedsecuring/clamping arrangements;• Confirm operation and safety features of anydedicated compressors or auxiliary machinery;• Anti-recoil valves, i.e. slingshot/Olmsted valves(test for proper functioning);• Check foundation fastening.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEHoisting and rotating systemsAnnualHoisting and rotatingsystemsComplete periodical• Visual survey;• Review of records ofmaintenance (e.g. includingsafety devices and “slip &cut” records);• Review records of the routinetesting of the drawwork’sEmergency Brake System,with function testing to theextent practical at time ofsurvey;• Spot-check function testing ofthe safety devices, particularlylimit switches and interlocks;• Visual examination ofdeadline anchor;• Confirm function test ofDrawworks Braking Systems(primary, secondary andemergency);• Inspect/ check records ondrawwork foundation bolts.Hoistingequipment,drawworks &deadline anchor• Such major components will normally have themajor overhauls carried out during the Completeperiodical Survey. Confirmation of recent majoroverhaul of components in presence of a DNVSurveyor to be reviewed;• Check calibration of deadline, load cell, etc;• Confirm correct torque of deadline clamp bolts;• Inspect and confirm operation of drawworks,including main and auxiliary brakes and reviewmaintenance and overhaul records. (Check/NDTdeadline anchor foundation bolts; these are oftenfound to be cracked);• Confirm operation of crown-saver device;• Calibration and sealing of load limiting valves (airpressure regulators or hydraulics. PSV’s) to beverified (very often found not done for e.g. utilitywinches, cherrypickers, overhead cranes etc.).DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnualHoisting and rotatingsystemsComplete periodical• Visual survey;• Review records ofmaintenance (e.g. Top Drivemainshaft NDT recommendedevery 6 months for somemodels).• Visual survey;• Review of records ofmaintenance.• Visual survey;• Review of records ofmaintenance.Rotating systems,top drives & swivelsincl. dollyTraveling blockCrown block• Such major components (top drive, swivel) willnormally have the major overhauls carried outduring the Complete periodical SurveyConfirmation of recent major overhaul ofcomponents in presence of a DNV Surveyor to bereviewed;• NDT testing of top drive dolly and guide tracks• Inspect and confirm satisfactory functioning ofguide dollies (especially retractable type); payattention to cracks in the welds due tomisalignment of the guide track and/or wear on thewheel• Confirm operation of rotary table safety features;• Confirm calibration of driller’s console torque andRPM indicators;• Examine pin for wear• MPI all load bearing parts• Pressure test pipework to maximum workingpressure for 15 minutes• Review manufacturers certification for new parts;Note:welding should not be done on hoisting toolswithout consulting the manufacturer. Without fullknowledge of the design criteria, the materialsused, and the proper procedures (stress relieving,normalising, tempering etc.) it is possible toreduce the capacity of a tool sufficiently to makeits continued use dangerous.• General wear and cracks;o Sheave grooves for wear and cracks.o Wear and cracks in block-to-hook adaptorfasteners.• Loose fasteners;• Dimensional checks;• Review certification for replacement parts (whereapplicable):• NDT of stripped block and shafts.• Bearing wear and sheave wobble;• General wear and cracks (check all welds);• Sheave grooves for wear and cracks;• Loose fasteners;• Dimensional checks;• NDT of striped block and shafts.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEBOP and pipe handlingAnnualBOP and pipehandlingComplete periodical• Visual inspection of cranes,winches and associatedsupporting structure/runwaybeams;• Review records ofmaintenance;• Spot check of safety features.• General visual survey;• Visual inspection of cranesand associated supportingstructure/runway beams;• Review records ofmaintenance.• General visual survey asabove;• Spot check of safety features.Horizontal pipehandlingVertical pipehandlingBOP, Xmas tree andriser overhead organtry crane• Load test as required and test overload protection;• Function testing of all safety features.• Check operation of parking bolts, limit switches,bumper stops;• Confirm hoisting and traversing functions over fulltrack length;• NDT as deemed appropriate.• Load test as required and test overload protection;• Function testing of all safety features;• Check operation of parking bolts, limit switches,bumper stops;• Confirm hoisting and traversing functions over fulloperational envelope;• NDT as deemed appropriate;• Calibration and sealing of load limiting valves (airpressure regulators or hydraulics. PSV’s) to beverified (very often found not done for e.g. utilitywinches, cherrypickers, overhead cranes etc.).• Inspection of crane and associated supportingstructure/runway beams;• Load test and test of overload protection• Confirm hoisting and traversing functions;• Check operation of parking bolts, limit switches,bumper stops and other safety features;• Calibration and sealing of load limiting valves (airpressure regulators or hydraulics. PSV’s) to beverified (very often found not done for e.g. utilitywinches, cherrypickers, overhead cranes etc.).• General visual survey asabove;• Spot check of safety features.BOP and Xmas treetrolley• Confirm travel over full track length;• Confirm operation of limit switches, bumper stops,parking bolts.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEBulk storage, drilling fluid circulation and mixing and cementingAnnualBulk storage, drillingfluid circulation andmixing and cementingComplete periodical• Visual inspection.• Confirm testing of safetyfunctions;• Review certification ofequipment (specially noteappropriate Ex protection);• Review records ofmaintenance/replacement tothe Cementing Unit (ref.Cementing Unit is normallytemporarily leased to vesselby 3rd party andoperated/maintained by the3rd party, therefore subject toexchange or modification inperiod since last survey);• If cementing unit is thedesignated EmergencyCirculation Pump, then crossconnectionto Choke & KillSystem to be confirmed;• Review of records of routinewall thickness checks on areassusceptible to erosion (ref.cement may contain someabrasives particles, thereforeerosion may be an issuewithin the normal 5 yearcycle, particularly in way ofbends & restrictions);• Pressure safety valves to besurveyed, records reviewed.Cementing• Check for clogging of discharge line from safetyvalves;• Pressure testing to max. WP of installed piping;• Confirm manifold gauges and driller’s gaugesannual calibration;• check wall thickness checks:o in way of the bends/fittings/constrictionssubject to potential erosion or corrosion andprecautionary inspection of pipe supportsparticularly in way of bends/constrictions;o proving that the pipe is strong enough;• Confirm cement pump safety valve setting andinspection of the H.P. discharge side of pump;• If the cement pump is the emergency kill pump,the starting system for the diesel engine is to bereviewed to ensure that the engines can startwithout use of the rig's air system. Specialattention to be paid on nonreturn valves, if fittedbetween start air bottles and rig air systems.• For diesel engines located in zone 2 areas, thesafety functions on the engine are to be tested.Typically these are lube oil low pressure, coolingwater high temp., high exhaust temp. andoverspeed trips. Insulation of the exhaust gasmanifold is to be surveyed.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnualBulk storage, drillingfluid circulation andmixing and cementingComplete periodical• General visual survey• Review of records ofmaintenance;• Review records of routinewall-thickness checks onareas susceptible to erosion(ref. mud may contain someabrasives particles, thereforeerosion may be an issuewithin the normal 5 yearcycle, particularly in way ofbends & restrictions).HP mud circulationpiping and valvesKelly cocks/ IBOP/valve in drillstring• Pressure test to maximum working pressure andNDE as appropriate. Open up 10% of standpipemanifold valves for inspection;• Confirm manifold gauges and driller’s gaugesannualy calibrated;• check wall thickness checks in way of thebends/fittings/constrictions subject to potentialerosion or corrosion and precautionary inspectionof pipe supports particularly in way ofbends/constrictions and top drive goose neck andcompare with minimum strength thickness;• Check of hose certification < 5 years (normallythese hoses are replaced regularly). If notinspection and pressure test to max. WP of rotaryhose and swivel.• Valve seat-sealing test at low pressure (approx.200/300 psi) and also at max. WP. If flow possiblein both directions valves to be tested from bothdirections• Functional testing;• Spot-check NDT at joints;• Visual survey;• Review of records ofmaintenance (fluid ends andsafety pop-off valves).Mud pumps• Confirm mud pump safety valve setting andinspection of the H.P. discharge side of the mudpumps;• Function test including safety features• NDT on welded pulsation dampers• Review records of regulartesting of the overboard dumpvalves in the mud pits(applicable for those floatingunits requiring to dumpvariable deck-load to achievesurvival conditions, ref.maritime/stability manualonboard vessel).Mud pits• Visual inspection of mud pits and spot-checkthickness checks;• Testing of system for monitoring mud return flowrate and level alarms.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnualBulk storage, drillingfluid circulation andmixing and cementingComplete periodical• Visual inspection ofaccessible equipment.• Review of records ofmaintenance.• Confirmation that the ventlines on the discharge side ofthe tanks safety valves/rupturediscs are kept clear fromblockages (there is tendencyfor blockages developing dueto carry over of bulk dust intothe vent line, especially indamp environments and atany low spots in the reliefline).•Bulk storage• Inspection and -check thickness checks (ref. bendsand restrictions) on installed piping systems.• Pressure testing to max. WP of installed piping.• Confirm safety valve setting and review records ofregular opening up/overhauls.• External and internal inspection of pressure vesselsand pressure test to max WP.• Confirm operation and safety features of anydedicated compressors.• Confirm bulk transfer routes operate satisfactorily(may use air as medium).• Confirm operation of remote control valves andcontrol panels.• Confirm operation of instrumentation (levelalarms).Well testing and associated well control systemAnnualWell testing andassociated wellcontrol systemComplete periodical• Visual inspection ofaccessible areas for bent ofdamaged members, includingfoundation connection,anchorage’s and securingarrangements.Flare booms• NDT on main structural components, supportconnection to hull and rotating pins as deemednecessary.• UT check/ pit testNote: Sometimes piping is part of the flarestructure, and if so often subject to loss ofthickness and pitting corrosion.• Review records of load test on flare boom (newload test may be required)DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnualWell testing andassociated wellcontrol systemComplete periodical• Review records ofinstallation/maintenance/replacements for the Well TestingPackage (ref. the Package isnormally temporarily leasedto vessel by 3rd party andoperated/ maintained by the3rd party). It is required thatthe installation of the WellTesting Package is surveyedimmediately prior to WellTesting start up by DNV. Thisshould be confirmed fromrecords onboard or followedup as per an installationsurvey;• Confirmation of satisfactoryroutine testing of the SafetySystems, ESD System and theBlow-down Systems bydocumentation review and byspot-check function tests;• Survey of any “temporary”articulated pipework (forpressure rating, routing andmechanical damage) locatedwithin the Well testingpackage and between the WellTest Package and the:o drill flooro flare boomso produced waterdischargeo storage and offloadingstations;• Arrangement to be checkedagainst approved HAZ areaplan;• Check last major survey oncomponents.Well testingpackage• Pressure testing to max. WP of installed piping;• Check wall thickness checks in way of thebends/fittings/constrictions subject to potentialerosion or corrosion and precautionary inspectionof pipe supports particularly in way of thebends/constrictions;• External and internal inspection of pressure vesselsand pressure test to max. WP;• Inspection and pressure test (manufacturers spec)of any flexible hoses;• Full functional testing of the associated SafetySystems and ESD System;• Confirm gauges and instrumentation correctlycalibrated.Other systemsAnnual Other systems Complete periodicalDET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAnnual Other systems Complete periodicalGeneral Visual Survey, spotcheck of relief valve calibrationrecords, load test records etc.Spot check safety systems.Winches for liftingpurposes• Function test including safety features, load test,NDE as appropriate;• Check wires.General Visual Survey, spotcheck of relief valve calibrationrecords, load test records etc.Loose drillngequipment/gear• Function test including safety features, load test,NDE as appropriate;• Calibration/ previous test records as appropriate.General Visual Survey, spotcheck of relief valve calibrationrecords.Pressure vesselsExternal/ internal survey and thickness checks as foundnecessary. Pressure test to max WP.• Function testing of main andsecondary braking systems byemergency stop, power failureor other related energyfailures;• Function testing of limitswitches , load limiting deviceand slack-wire autostops;• Function testing of controlledemergency lowering/hoistingdevice upon power failure;• Function testing of controlhandles at operating panels(confirming handles autoreturnto the stop positionwhen not being manuallyoperated);• Operating procedures foremergency operations to beposted and other marking ingeneral.ManridingequipmentFunction test including safety features, load test, NDEas appropriateDET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCE4 HANDLING OF CERTIFIED EQUIPMENT4.1 EQUIPMENT REPAIRS AND OVERHAULSRepairs introductionDNV should be involved in any repairs pertaining to category I equipment, and as such should be notified ofthese. It is directly underlined that, assuming the required quality control and technical standards aremaintained and procedures are followed, DNV does not have a requirement for repairs by OEMs.Category I equipment shipped onshore for repair, refurbishment or re-manufacture, shall be accompanied bysigned certification or existing Certificate. In order for DNV to recertify an item of equipment, it must beestablished that the equipment was certified in the first place. Items shall be marked & traceable to the signed/existing certification.The general process of DNV’s involvement is shown in Figure 11.Start•It is recommended to require DNV services in the PO. The Cert of Conformity and any otherpertaining document should be made available to the repair shop or overahuling or on boardrepairs. A kick off meeting is to be held.Survey•at start and during repair surveyTesting•after repair survey. For additionial information on test requirements see Table 1•Review of final documentation. For detailed information on documentation requirements seepar 4.3. Issue final overhaul documentation.DocumentationFigure 11Depending on the character of the repairs, DNV’s knowledge of the relevant repair shops (and subcontractorsas applicable), the survey and testing may be reduced. Minimum reporting level from DNV is that minutes ofmeeting or survey report should be issued after the first step and a final survey report should be issued afterthe review of final documentation.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCETable 1 overview on test requirements. See par. 1.5 for definitions of overhaul and re-manufacturing.Performance testOver-pressure testingRequired if sealing elements have been Not requiredMaintenancebroken and reassembled. Review of graphson a spot check basis only.Overhaul 1 Required – DNV to witness Not requiredRe-manufacturing 2 Required – DNV to witness required12Equipment that is subject to “an overlay procedure which has no impact on the base material properties and does not violate anydesign parameters for structural integrity” is not classified as welding: i.e. local ring groove overlay repair needs pressure testing tomaximum working pressure onlyFor Ring groove welding see “overhaul”Additional DNV involvementIn addition to the general process as described above, some elements of repair and overhaul require additioninvolvement from DNV as shown in Table 2.Table 2 Listing of repair and overhaul requiring additional DNV involvement.ElementWelding aspectsDNV InvolvementWeld Procedures proposal for use should be reviewed and accepted before any welding takesplace.Sour serviceSour service (H2S) is almost always specified. Typical maximum hardness for carbon steel is22HRC, 248HV Vickers or 24SHV or 237HB maximum. This also goes for the hardnessexamination of the macro of the weld procedure qualifications. (Ref. ISO 15156, NACE MR0175).Weld Repairs • Welding activities to be monitored by DNV;• Suitability of the weld procedure qualification record (WPQR) is to be verified to thematerial of the item to be repaired (prior to commencement of work);• Welder qualifications review (prior to commencement of work);• Electrode certificates (Note that max. Nickel content allowed acc. to NACE = 1%);• Pre-weld NDE:o Hardness checks,o MPI/DPI of machined surfaces,o Copper sulphate etching test required to confirm any existing stainless steeloverlay weld removal before weld overlay repairs.• Post weld NDE:o Hardness checks,o MPI/DPI of machined surfaces,o Ultrasonic tests of welded/machined overlay surfaces,o Radiography or ultrasonic tests of full penetration welds,o MPI of fillet welds,o NDE operators’ qualifications to be reviewed.• Post weld heat treatment (PWHT):o Calibration certificates for equipment used.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCE4.2 CERTIFICATION OF TEMPORARY EQUIPMENTTemporary Equipment ModuleIn general, temporary equipment should meet the same safety and reliability standards as permanentlyinstalled equipment. In addition, it is important to consider the impact and interfaces on the platform as listedin Figure 12 and be sure that no additional safety risks are created.System footprint•Deck loading•Fire protection – structural and active•Hazardous areas created•Escape routes that will be affected•EnvironmentSupply aspects•Electrical – main and emergency•Hydraulic•Pneumatic•Water – pottable and coolingImpact on platformReturn aspects•Routing of pressure relief systems•Drainage•Thermal load•Contamination of systems•EarthingSafety issues•ESD aspects•Hot surfaces•Comms in / Communication•Escape routes•Fire & Gas•Fire dampers•Emergency LightingFigure 12 Overview of impact on safety of platformTo cover the above, DNV has adapted a certification process as is discussed in detail in the Offshore TechnicalGuide No. 5 and is displayed in the figure below. The process is centered on so called ‘modules’ covering thewhole equipment skid necessary for a project/job. The process results in a ‘Certificate for TemporaryEquipment Modules’ documenting the successful completion of the process.After the completion of the certification process, the temporary equipment is subject to the same surveyrequirements as permanent installed equipment.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEFigure 13 process covering temporary equipmentComponentsAs explained above focuses the OTG-5 on modules or system sets. A part of the process is however theverification of certification requirements on component level as shown in Figure 13, 2 nd block from below. Ingeneral, certification requirements for essential systems inside the scope of the DRILL notation is the samefor temporary equipment as for permanently installed equipment (see also Appendix A for a description ofwhat is within the scope of DRILL Class).The above implies that the same certification process is required as given during the introduction in class inchapter 2 and displayed on Figure 4 of this chapter. At the same time it is underlined thata) The actual process to be followed depends on an assessment of the component specific risks, takinginto account experience of the manufacturer on the component under certification, its quality controlsystem, the complexity of the design etc.b) DNV rules allow consideration of ‘equivalent solutions’ having the same safety level as the DNV rules.To summarize, the component certification of temporary equipment follows a case by case approach based ona documented risk assessment to decide on the required process.4.3 DOCUMENTATIONDuring a complete periodical survey a DNV Surveyor shall review:a) the original certification documentation for any new equipment since the last Complete periodicalsurvey,b) the documentation of modifications of/ refurbishment to existing (previously certified equipment andc) check the traceability of the remaining certified equipment on a spot check basis.This paragraph gives an overview of the documentation as is expected for all category I equipment. In addition,it includes guidelines how to proceed when parts of the required documentation is missing. It concludes with adescription of specific cases resulting from a vessel not build under DNV’s DRILL class or after class transfer.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEExpected documentationUnits with a DNV DRILL class are expected to have an equipment list covering all equipment in category I.See Appendix A for a complete overview of this equipment. The table below informs on most importantdocuments issued during the certification process.Table 3 Overview of the documentation used in the certification processDesign verificationreport, (DVR)• The DVR shall be issued by the design approval responsible for all equipment ofcategory I, unless covered by a valid type approval certificate.• In addition to each individual equipment, DVRs shall be issued for each system(including control systems) not covered by plan approval. The DVR shall contain allinformation needed to be followed up by the surveyor attending fabrication survey andinstallation of the equipment, and as a minimum include:o design codes and standards used for design verification,o design specification (e.g. temperature, pressure, SWL, service design loadetc.),o follow-up comments related to e.g. testing, fabrication and installation of theequipment or system. An approval letter may be issued instead of a DVR,however such a letter shall as a minimum contain the same information aslisted above.REPORTFOR INCOMPLETECERTIFICATIONA Report For Incomplete Certification (or Inspection Release Note) shall only be issued if thecomponent is delivered prior to issuance of product certificate (PC) or Survey report. A final PCshall not be issued if there are non-conformances to the equipment or system. The Report ForIncomplete Certification shall be used with detailed description of the non-conformances, andshall always be replaced by a product certificate or survey report when all non-conformances areclosed.Product certificate,(PC)A PC, sometimes known as DNV-Certificate of Compliance (CoC) is issued for all category Iequipment and systems (including control systems).The certificate is issued upon successful completion of design verification, fabrication surveyand review of final documentation. As stated above, the PC shall not be issued if designverification or non-conformances are outstanding.Missing documentation; how to proceedExperience has shown that the operator/owner may be faced with the problem that drilling equipment ofmajor significance to safety is lacking documentation. This is not only a deviation from specific documentationrequirements, it makes it also impossible to verify compliance with the requirements of DNV’s DRILL notationand as such have confidence in the safety and reliability of the system.It is therefore important to have a process to regain confidence of the system. As part of system maintenanceand quality system, it is under the owner’s responsibility to initiate such a process leading to the requirementdocumentation as can be used as a foundation for DNV’s DRILL notation. Such a process normally includes thesteps detailed in Figure 14. Of course DNV shall support both before, during and after the process to:a) ensure expectations and needs are alignedb) the process is started with correct outcome (i.e. as basis for contracts)DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEc) verify the correct proceedings andd) documents completion of the process and its results.Confirmation•Confirmation from manufacturer that the equipment was originally manufactured in accordance with recognizedmethods, codes and standards. Alternatively, this step may confirm DNV has certified a similar design (with referenceto DVR number)Analysis•Chemical analysis of elements/ chemical composition analysis (spectrography);•hardness mesurements(check also conformance with ISO 15156/ NACE as applicable).History•Equipment history (year of manufacture, service history, repair history). For plastic replicas, it is not required that DNVshould take the photographs, but can do if requested. However, the original picture, preferably 1:100 magnification(preferably black/white), are to be evaluated by metallurgist within DNV with respect to brittle fracture. Since it is notpossible to determine any toughness properties without doing a destructive test, a minimum design temperature forthe equipment will be established based on experience.Inspection•Critical dimensions should be confirmed to be within manufacturer tolerances. Look for evidence that enhances thelevel of confidence in the similarity in the material data. This is to reduce the number of material tests that werequire. Where possible examine any parts that have to come off for repair, i.e. parts removed because of damage. Ifyou have 10 similar pieces 3/10 may be appropriate as a test scope. However, for items like riser joints all piecesshould be considered due to likelihood of them having been replaced.Testing•NDT (MPI, replica etc.);•Pressure testIf no records of witnessed proof tests are availalbe, a test is required to rate design pressure (including low-pressureseal tests).For equipment after major repairs see par. 4.1;•Function test.Figure 14 Process flow regaining conifidence in case of missing documentationNot build under DNV’s DRILL classA specific case may be when the documentation is missing since the vessel was not build under DNV’s DRILLnotation (or a comparable notation with identical scope and certification requirements from other classsocieties). This implies that Class had a limited scope during the newbuilding fase, therefore has not enforcedcertification of these systems and subsequently, has no ground for confidence to the drilling equipment.A follow up can follow two alternatives:DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEa. Compliance to the DRILL standard is desirable; a follow up process as described for missingdocumentation earlier in this paragraph for all equipment is followed to regain confidenceand build up relevant documentation. If completed the vessel can get DRILLb. Compliance to DRILL standard is not required but inspection of drill equipment by 3rd partyis. Such a service can be provided following the same scope of a normal DRILL-inspection. Theresult shall be documented by a survey report but shall not lead to a DRILLnotation.Conclusively, it is again underlined that a class transfer itself does not imply automatically cases of missingdocumentation. If the classification society as involved during newbuilding followed scope and certificationrequirements are comparable with the scope of DNV’s DRILL, all the relevant certification documents should beavailable and are accepted by DNV for a follow up under operation. DocumentationDET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEAPPENDIX AOVERVIEW OF CERTIFIED EQUIPMENTThe tables below list the certification categories of the specific systems inside the scope of the DRILL notation.The table below is reproduced from DNV-OS-E101, 2009 edition, Ch. 3. For the latest edition seehttp://www.dnv.com/resources/rules_standards/index.asp. Approval category I requires a Product Certificateas issued by DNV, approval category II requires a Work Certificate as issued by the manufacturer. Note that thecategorisation and associated certification requirements can be updated in new revisions of the DRILL standardto reflect evolvements of system design and manufacturing standards.Table A1 Drilling structuresMaterial or equipmentDNV approval categoriesIIIDrilling structures Derrick and other drilling tower designs XOther designXMiscellaneous Skids and lifting brackets intended for installation lifts XSkids and lifting brackets intended for regular liftsXTable A2 Well control systemsMaterial or equipmentDNV approval categoriesBlowout preventionequipmentHydraulic connectors for wellhead and riserRam preventersAnnular preventersAccumulators for subsea stackSubsea fail-safe valves in choke and kill linesClampTest stumpBOP test pumpValves in drillstringIXXXXXXXXIIXBlowout prevention, controlequipmentDiverter unit, equipmentand control equipmentChoke and kill, equipmentand control equipmentAccumulators in control systemXWelded pipes and manifolds 1)XUnwelded hydraulic pipingFlexible control hosesHydraulic hose reelControl podsXAcoustic BOP control equipmentXDiverter house with annular valveXDiverter piping 1)XValves in diverter pipingXDiverter handling toolXChoke manifold 1)XAll piping to and from choke manifold including choke, kill, and booster lines X 1)Flexible hoses for choke, kill, and booster linesXUnions and swivel jointsXEmergency circulation pump – pressure sideXXXXDET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCETable A2 Well control systemsMaterial or equipmentDNV approval categoriesMarine riser, equipmentand control equipmentBall joint and flexible jointRiser sections including jointsSupport ring for riser tensioningRiser Spider & GimbalRiser Handling and Running ToolsTelescopic jointAccumulatorsIXXXXXXXII1) Certification shall cover system design, manufacture and testing. Requirements to individual piping components; see Table A9.Table A3 Heave compensation and tensioning systemsMaterial or equipmentDNV approval categoriesIGeneral Hydraulic cylinders and other pressure vessels 1) XPiping including flexible hoses 2)XHydro-pneumatic accumulatorsXAir compressors and air dryersWire ropesSheavesHeave compensation Heave compensator system assembly XLoad carrying parts in compensator systemXDeadline compensatorXTensioning systems Riser tensioner system assembly XLoad carrying parts in tension systemXGuidelines and podline tensioners/tension winchesXTelescopic arms for tension linesXTripsaver skid/trolleyXAir control skid with manifoldAnti-recoil valveXSwivels and goosenecks on tension cylinders 1)XIIXXXX1) See Table A102) Certification shall cover system design, manufacture and testing. Requirements to individual piping components; see Table A9.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCETable A4 Hoisting and rotating systemsMaterial or equipmentDNV approval categoriesConventional hoisting system Sheaves for crown block and travelling blockHydraulic cylinder basedhoisting system(ramrig/cylinder hoisting rig)Hoisting equipment inderrickCrown block including support beamsGuide track and dollyTravelling blockDraw works including foundationDeadline anchorLifting cylinders (rams)YokeYoke sheavesSheave clusters including support beamsGuide track and dollyEqualizersDeadline anchorDrilling hook 1)Swivel 1)LinksSpidersElevatorsElevator bushing/insertDrilling line and sand lineCranes in derrickRotating equipment Rotary table including skid adaptor and driving unit XKelly with kelly cock arrangement 1)Master bushingKelly bushing 1)Topdrive 1)IXXXXXXXXXXXXXXXXXXXXIIXXXXX1) Other types of equipment having similar function as the ones listed above are to be equally categorised.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCETable A5 BOP and pipe handlingMaterial or equipmentDNV approval categoriesIIIPipe handling Racking arms including possible lifting head XManipulator armsXGuide track and dollyXCatwalkXHorizontal to vertical (HTV) equipmentXPipe handling Crane incl. Gripper yokesXFinger board incl. belly boardXMousehole (If powered, cat I will apply) X XBOP & Xmas tree handling Blowout preventer crane or carrier, skid, guide frame, sea fastening, etc. XMiscellaneous Power tongs for pipe handling or iron roughneck XKelly spinnerXPower slipsXTable A6 Bulk storage, drilling fluid circulation and mixing and cementingMaterial or equipmentDNV approval categoriesBulk storage Pressurised storage tanks 1) XDrilling fluid circulationand mixingPiping for pressurised bulk transport 2)Safety valves 3)Pumps for bulk transportDrilling fluid pump – pressure sideStandpipe manifoldPulsation dampersCirculation head piping including drilling fluid pump discharge 2)Mud hosesSafety valves 3)Piping for mixing of drilling fluid, and suction line to drilling fluid pump 2)Centrifugal pumps for mixing / transfer of drilling fluidRotary hose assemblyKelly cocksDrill stringMud return pipe 2)Shale shakerDrilling fluid tanksDegasser including piping to burners or to vents 1)and 2) X XChemical mixersAgitators for drilling fluidCementing Cement pump – pressure side XCementing headCement manifoldPulsation dampersIXXXXXXXXXXXXIIXXXXXXXXXXDET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCETable A6 Bulk storage, drilling fluid circulation and mixing and cementingMaterial or equipmentDNV approval categoriesCirculation head piping including cement pump discharge 2)Cement hosesSafety valves 3)Centrifugal pumps for cement mixing / transfer of cement slurryPiping for mixing of cement, and suction line to cement pump 2)IXXXIIXX1) See Table A10.2) Certification shall cover system design, manufacture and testing. Requirements to individual piping components; see Table A9.3) Design review of valve and bursting disc is not required. The extent of witnessing of leak-, calibration-, capacity- and qualification- testing to beagreed with DNV based on manufacturer’s QA/QC system. DNV shall normally witness batch qualification tests of bursting discs.Table A7 Well test systemsMaterial or equipmentDNV approval categoriesIWell test systems Piping including flexible hoses 1) XPressure vessels and separators 2)XHigh pressure pumps – pressure sideXOther pumpsBurnersXFlare boomsXSafety valves 3)XIIX1) Certification shall cover system design, manufacture and testing. Requirements to individual piping components; see Table A9.2) See Table A10.3) Design review of valve and bursting disc is not required. The extent of witnessing of leak-, calibration-, capacity- and qualification- testing to beagreed with DNV based on manufacturer’s QA/QC system. DNV shall normally witness batch qualification tests of bursting discs.DET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCETable A8 Other systemsMaterial or equipmentDNV approval categoriesIIIWinches Winches for lifting purposes XWinches for non-lifting purposesXMan riding equipment Man riding winches, access boards or baskets, etc. XMiscellaneous Hydraulic power units including pumps and manifolds XSkids or carriers for handling of equipment at height or over moon poolXRails for cranes, skids and other equipmentXNon-redundant gear transmission and brakes for critical applicationsXTable A9 Categories for pipes, fitting and valves in drilling systemsMaterial or equipmentDNV approval categoriesPiping systems(including spools)Piping listed in DNV-RP-D101 Sec.3.15.6, Pipe Stress Priority PipingAll other piping NOT listed in DNV-RP-D101, section 3.15.6Flanges and couplings Standard flanges and pipe couplings XFlexible hosesNon-standard flanges and pipe couplings used in category I piping systemsFlanges and pipe couplings other than those mentioned above, and flanges andcouplings for category II piping systemFlexible hoses for systems requiring continuous operation and for whichfailure of flexible hose is considered critical.Valves Valve body of welded construction with ANSI rating > 600 lbs XValves designed and manufactured in accordance with recognised standardsComponents of high strength Specified yield strength > 345 Mpa (50 000 psi), or tensile strength > 515materials 1) Mpa (75 000 psi)1) Components made according to recognised standard where the material requirements allow use of high strength steel may be accepted as category II.IXXXXIIXXXTable A10 Categories for pressure vesselsMaterial or equipmentDNV approval categoriesPressure vessels for Poisonous liquids XLiquids with flash point below 100°CLiquids with temperature above 220°CCompressed gases, where pressure ×volume (P × V) is above 1.5, wherepressure (P) is in bar and volume (V) is in m 3Other Pressure vessels that are not included in category I XCylinders Cylinders for lifting purposes XCylinders for non-lifting purposesIXXXIIXTable A11 Categories for control systemsMaterial or equipmentDNV approval categoriesIIIDET NORSKE VERITASAppendix AOTG-07

OFFSHORE TECHNICAL GUIDANCEControl systems Blowout prevention (BOP) XDiverterXChoke & KillXMarine riser equipmentXHeave compensatingXActive heave draw workXRiser tensionXOther systems 1) X X1) Categorization will depend on criticality of the system, i.e. whether any potential failures are considered to be critical or not.DET NORSKE VERITASAppendix AOTG-07