norsok d-sr-005 on coiled tubing

NORSOK STANDARD

SYSTEM REQUIREMENTS

COILED TUBING EQUIPMENT

D-SR-005Rev. 1, January 1996

Please note that whilst every effort has been made to ensure the accuracy of the NORSOK standardsneither OLF nor TBL or any of their members will assume liability for any use thereof.

Coiled tubing equipment D-SR-005 Rev. 1, January 1996

NORSOK standard Page 1 of 15

CONTENTS

1 FOREWORD 2

2 SCOPE 2

3 NORMATIVE REFERENCES 2

4 DEFINITIONS AND ABBREVIATIONS 24.1 Definitions 24.2 Abbreviations 3

5 FUNCTIONAL REQUIREMENTS 35.1 General 35.2 Product/services 35.3 Equipment/schematic/borderline 35.4 Process/ambient conditions 45.5 Performance and operational requirements 45.6 Maintenance requirements 45.7 Layout requirements 45.8 Interface requirements 55.9 Commissioning requirements 5

ANNEX A COILED TUBING EQUIPMENT REQUIREMENTS 6

ANNEX B WELL CONTROL SYSTEM REQUIREMENTS 8

ANNEX C PRIMARY WELL CONTROL SYSTEM 10

ANNEX D SECONDARY WELL CONTROL EQUIPMENT 11

ANNEX E TERTIARY WELL CONTROL SYSTEM (SAFETY HEAD) 12

ANNEX F COMPUTERISED DATA ACQUISITION SYSTEM (CDA) 13

ANNEX G MINIMUM DOCUMENTATION REQUIRED 14



1 FOREWORDNORSOK (The competitive standing of the Norwegian offshore sector) is the industry initiative toadd value, reduce cost and lead time and remove unnecessary activities in offshore fielddevelopments and operations.

The NORSOK standards are developed by the Norwegian petroleum industry as a part of theNORSOK initiative and are jointly issued by OLF (The Norwegian Oil Industry Association) andTBL (The Federation of Norwegian Engineering Industries). NORSOK standards are administeredby NTS (Norwegian Technology Standards Institution).

The purpose of this industry standard is to replace the individual oil company specifications for usein existing and future petroleum industry developments, subject to the individual company's reviewand application.

The NORSOK standards make extensive references to international standards. Where relevant, thecontents of this standard will be used to provide input to the international standardisation process.Subject to implementation into international standards, this NORSOK standard will be withdrawn.

2 SCOPEThis standard describes functional, performance and operational requirements for the coiled tubingequipment.

3 NORMATIVE REFERENCESAPI RP 16E Design of control systems for drilling well control equipmentAPI RP 53 Recommended practice for blow-out prevention equipment systems for

drilling wellsASTM A 370 Test methods and definitions for mechanical testing of steel productsASTM A 450 Specification for general requirements for carbon, ferritic alloy, and

austenitic alloy steel tubesASTM E 18 Test methods for rockwell hardness and rockwell superficial hardness of

metallic materialsASTM E 94 Guide for radiographic testingASTM E 140-88 Hardness conversion tables for metalsISO 10400 Formulae and calculation for casing, tubing, drill pipe and line pipe

propertiesISO 10423 Specification for valves, wellhead and christmas tree equipmentNACE MR0175 Sulphide stress cracking resistant metallic materials for oil field

equipment

4 DEFINITIONS AND ABBREVIATIONS

4.1 DefinitionsNormative references Shall mean normative in the application of NORSOK standards.Informative references Shall mean informative in the application of NORSOK standards.Shall Shall is an absolute requirement which shall be followed strictly in order

to conform with the standard.



Should Should is a recommendation. Alternative solutions having the samefunctionality and quality are acceptable.

May May indicates a course of action that is permissible within the limits ofthe standard (a permission).

Can Requirements are conditional and indicates a possibility open to the userof the standard.

The well control system is divided in the following three distinct logic groups, referenced frombelow the injector to the x-mas tree:• Primary well control system designed to enable efficient coiled tubing operation, this is the

strippers (stuffing boxes), the coiled tubing body and the dual flapper check valves, alternativelyplugged end of the coiled tubing.

• Secondary well control system designed to meet or exceed requirements for a secondary barrierelement as during normal drilling operations. As a minimum it consists of three independentrams; blind/shear, tubing, slip. Connections to this system shall be with metal to metal seal.

• Tertiary well control system, safety head. A separate independent shear/seal BOP fitted as closeas possible to the wellhead with metal to metal seal connections and with an entirely independentclosing unit.

4.2 AbbreviationsNone.

5 FUNCTIONAL REQUIREMENTS

5.1 GeneralThe coiled tubing unit and BOP systems shall be capable of handling the work string, wellconditions and other work parameters specified by the work program.

5.2 Product/servicesTypical service performed by a coiled tubing unit:• Pumping.• Milling/drilling (junk-, scale-, window-, hole-).• Clean-out.• Lifting.• Operate downhole tools (packers, plugs etc.).• Fishing.• Logging.• Perforating.

5.3 Equipment/schematic/borderlineThe system normally consists of the following main items:• Injector head w/control system and frame(s).• Hydraulic power system.• Coiled tubing reel assembly.• Control cabin with data acquisition system.• Rig-up equipment.• Well control system.



• Coiled tubing w/ BHA.• Fluid/nitrogen pump.

5.4 Process/ambient conditionsThe well control system with connected valves, hoses and piping shall be designed for the followingconditions:Maximum well pressure 345 Bar (5000 psi)Maximum wellhead temperature 121ºC (250ºF)Minimum operating temperature -10ºC (14ºF)Formation fluids YesH2S YesCO2 YesOil and water based drilling muds YesBrine YesDiesel YesGlycol YesAcid (inhibited) YesCement slurry YesNitrogen Yes

Well control and pilot hoses and connections shall be capable of withstanding 700ºC for minimum15 minutes.

5.5 Performance and operational requirementsCoiled tubing equipment:• Ref. annex A.

Well control system:• Ref. annex B, C, D and E.

5.6 Maintenance requirementsMaintenance program with defined frequencies and work scopes.Re-certification program.Non-conformance system.Documentation system.

5.7 Layout requirementsSecure area of CT operations.Escape ways.Locate second (back-up) control panel for secondary well control system away from CT controlhouse in safe area.Locate one control panel for tertiary well control system away from CT control house in safe area.Secure frames and injection head so that rig up can withstand 46 m/s (90 knots) wind.Secure high pressure lines.Sufficient illumination.



5.8 Interface requirementsMechanic, electric, hydraulic and pneumatic connections shall be compatible with the rig orplatform connections.

5.9 Commissioning requirementsFunction testing of all relevant coiled tubing unit components including all accessory equipmentshall be performed prior to each job.Function testing and verification of the injector head positive and negative weight indicator systemshall be performed prior to each job.Documentation/verification of acceptable rig up versus forces and bending momentums.Documentation/verification that coiled tubing downhole tools, well control systems, frames, injectorhead and pumps can handle expected work conditions inside set safety factors.

Coiled tubing equipment D-SR-005Annex A Rev. 1, January 1996


ANNEX A COILED TUBING EQUIPMENT REQUIREMENTSInjector head:• Variable gripping force designed to minimise tubing damage and prevent tubing slippage.• Hydraulic motor and control system must provide accurate fine movement control in and out of

the well.• Replaceable gripper blocks.• Fail safe system that will stop chains from moving if hydraulic power lost.• Weight cells with both positive and negative weights.• Hydraulic force control that can be pre-set and adjusted. Displayed in control cabin. Pressure

with corresponding load and available hydraulic pressure.• Pull capacity 140% of maximum expected work string weight.• Snubbing capacity 120% of maximum anticipated snubbing force.• Anchored on minimum 4 anchor points or alternative system with equal strength according to

design criteria for the system to be used.

Injector support frame:• Withstand all dynamic, static and bending forces.• For non-derrick operation.• Anchored on minimum 4 anchor points or alternative system with equal strength according to

design criteria for the system to be used.

Lifting frame for floaters and semi-submersibles:• Withstand maximum anticipated axial load.• Contain a work window in which the injector head/stripper/BOP can operate isolated from the

motion of a floater.• Integrated winch for independent handling of the injector, well control equipment and other

hook-up equipment. The winch shall be remotely operable from the lifting frames work platformand the rig floor.

• Work platform at the lift frames' lower part.• An injector guide system on the vertical frame members for supporting the injector to the lift

frame during operation.

Goose neck:• Minimum arc radius equal to drum core diameter of the tubing reel.• Shaped rollers.• Withstand backforce from reel.• Guide system to prevent the coiled tubing from sliding off the gooseneck sideways.

Hydraulic diesel driven power unit:• Capacity to continuously and simultaneously operate coiled tubing injector, reel drive and

charging system.• Manual ESD system.

Overspeed on diesel engine:• Gas detector on air inlet with audible/visible alarm.• Zone 2 certified diesel engine.

Coiled tubing equipment D-SR-005Annex A Rev. 1, January 1996


• Highest permissible noise level: 90dB at 1m distance.

Coiled tubing:• Withstand all expected downhole forces.• Drifted before each operation. Size of drift ball shall be acceptable for upcoming operation, and

be larger than balls for tool operation. For coiled tubing strings with E-line installed or otherobstructions, other ovality check shall be performed.

• Also see annex G.

Reel:• Fluid manifolds: Inlet and isolation valves, launcher with by-pass, rotary joint and isolation

valves, pressure sensing device.• String isolation valve upstream reel axle and swivel joint.• Minimum core diameter (inches) 48 times coiled tubing outer diameter.• Pressure relief valve upstream reel axle and swivel joint and with protection cap.• Top end mechanically secured.• Level wind system.• Hydraulic motor.• Drive speed higher than maximum injector speed.• Adjustable back-force for preventing excessive pull on goose neck and with fail safe brake to

prevent damage to coiled tubing and goose neck.• Top termination with qualified high pressure connection.

Control cabin:• Light for minimum 30 minutes in control cabin if power is lost.• Minimum 2 independent escape routes.

Pump with diesel/combustion engine:• Fluid end and engine designed to handle expected rate and pressure.• Manual ESD system.

Overspeed on diesel engine:• Gas detector on air inlet with audible/visible alarm.• Zone 2 certified diesel engine.• Highest permissible noise level: 90dB at 1m distance.

Depth metering:• Fail safe with independent back-up system.

Bottom hole assembly:• Withstand all expected downhole forces• It shall minimum consist of from top and down, end connector and double flapper/back-pressure

valves.• Double flapper back-pressure valves can be substituted with tested plug.

Holding/mixing tank:• Clean so as not to cause plugging in coiled tubing and bottom hole assembly.

Coiled tubing equipment D-SR-005Annex B Rev. 1, January 1996


ANNEX B WELL CONTROL SYSTEM REQUIREMENTSBOPs:• Minimum working pressure 345 bar (5000 psi).• Minimum nominal bore for secondary and tertiary well control system equal to or greater than X-

mas tree bore.• Minimum pressure rating on BOP outlet flanges 345 bar (5000 psi).• The secondary and tertiary well control system shall be equipped with a panel with alarm for low

accumulator pressure, loss of power and low level of control fluid.• There shall be separate motion selector valves for each BOP function in control panel.• The motion selector valves must be located and arranged so that accidental operation does not

occur.• All rams to be interchangeable in all ram cavities, with the exception of rams equipped with

oversized accumulator or booster for shearing.• All types of rams to be capable of centring without damaging relevant pipe/tubing/line/against

side loads.• Each ram must have an external indicator showing open or closed position.• Ram locking system required, to enable manually locking of the rams.• There shall be documentary evidence that the pressure capacity of the accumulators are capable

of operating the rams according to the design requirements.• If alternative connections, they shall be qualified and certified to withstand the required forces

and pressure integrity. Metal to metal seal, except for hydraulic quick union type connectionbetween primary and secondary well control systems. This shall have flanged interface to thesecondary well control system. Such a quick union shall on the down side have a nominal boreminimum equal to the nominal bore of the secondary well control BOP.

• Control panel which clearly indicates whether the valves are open or closed.• Shear blind capability shall be available when the coiled tubing is unloaded, in tension or in

compression.

Hook-up valves to well control system:• ID 50.8mm (2") nominal bore.• Minimum pressure rating 345 bar (5000 psi).• Check valves if used shall be of a flapper or cone design.• All BOP outlets and inlets shall be with metal to metal seal connections.• All BOP outlets and inlets shall be fitted with valves.• Valves shall be bi-directional and have metal to metal sealing on the bore.• One of the valves to BOP outlet or inlet shall be remotely operated.• Valves and connections in primary well control system may be of a threaded design.• Threaded connections are permissible only after the second valve away from the well/riser bore.

Choke manifold:• ID 50.8mm (2") nominal bore.• Minimum pressure rating 345 bar (5000 psi).

Piping:• Minimum interconnecting pipe spools 50.8mm (2").• Minimum interconnecting piping pressure 345 bar (5000 psi).• Associated valves and piping etc. to be of compatible size and ratings.

Coiled tubing equipment D-SR-005Annex B Rev. 1, January 1996


Accumulators:• All preventors in the secondary and tertiary well control systems shall be used as basis when

calculating accumulator capacity.• Sufficient capacity for three operations (close, open, close) plus 25% of the volume of one

closing operation for each of the rams.• Accumulator capacity shall be calculated according to the following minimum requirements:

Sufficient volumetric capacity for three (3) operations (close, open, close) for all rams, plus 25%of the volume of one closing operation for each of the rams. Sufficient pressure capacity toenable cutting the coiled tubing in accordance with the following requirements:Sufficient remaining accumulator pressure to enable cutting of the coiled tubing after havingused a volume corresponding to:- Closing and opening of one annular preventer.- Closing, opening and closing of one pipe ram.Alternatively a dedicated shear ram auxiliary pressure system may be installed to meet theminimum requirements for cutting the coiled tubing if the remaining accumulator pressure isinsufficient to enable cutting after having performed operations as mentioned above.

• There shall be documentary evidence that the pressure capacity of the accumulators are capableof operating the rams according to the design requirements.

• Regulators in the system shall remain unaffected in the event of loss of power.

Well control hoses and connections including pilot hoses for well control purpose:• Fire resistant, capable of withstanding 700ºC for minimum 15 minutes.

Riser:• Minimum pressure rating 345 bar (5000 psi).• Metal to metal seals.• Designed to withstand the most unfavourable combination of expected forces that can be

encountered during an operation.

Coiled tubing equipment D-SR-005Annex C Rev. 1, January 1996


ANNEX C PRIMARY WELL CONTROL SYSTEMExternal system (strippers):

Location:• Above secondary well control system.• Top stripper to be located at shortest possible distance from the traction chains to minimise

buckling potential when snubbing.

Design:• Minimum working pressure 345 bar (5000 psi).• Seal elements on the strippers to fit proper temperature range.• Seal elements replaceable with coiled tubing located inside.• Wear bushings replaceable with coiled tubing located inside.• It shall be possible to remove coiled tubing with increased and/or oval outer diameter and/or

other changes in the tubing shape through the stripper by removing the bushings and elements.• Strippers shall be a dual system that can be individually and hydraulically controlled from the

control cabin.• A relief system shall be incorporated if over-pressurisation may occur.• Injection port on the strippers for corrosion inhibitor/lubricant injection.• Port on the strippers for monitoring wellhead pressure.• Pressure in the actuator on the strippers must be maintained regardless of prime mover operation.

Backup hand pump or air pump operation.• Hydraulic quick union type connection located between primary and secondary well control

system. Such a quick union shall on the down side have a nominal bore min. equal to thenominal bore of the secondary well control BOP. There shall be flanged interface to thesecondary well control system.

• If alternative connections, they shall be qualified and certified to withstand the required forcesand pressure integrity.

Internal system (dual flapper valves or plug and coiled tubing body):• Withstand maximum expected collapse and burst pressures.• Verified by surface testing.

Coiled tubing equipment D-SR-005Annex D Rev. 1, January 1996


ANNEX D SECONDARY WELL CONTROL EQUIPMENTDesign:• Secondary well control system to be operable from control house and from secondary safe

location.• The system shall be separate from all other hydraulic circuits, i.e., only the BOP stack can take

fluid from the storage accumulator.• Minimum three independent rams: blind/shear, tubing, slip.• Rams to be able to close and open against full working pressure. The maximum pressure the

rams can open or close against, with 200 bar (3000 psi) operating pressure, to be stated. Hang offcapacity compatible with coiled tubing weight.

• Equalising valves on the BOP system shall be an integral feature, providing pressure-equalisingpaths around the blind and the tubing rams.

• A side connection with metal to metal seal of at least 50.8mm (2") nominal bore is requiredbelow the shear rams. During operations, this connection will be closed with two full boreflanged isolating valves. One of the valves shall be remotely operated.

Shear/blind rams:• The shear/blind rams shall be a combined shearing and blind ram capable of shearing the coiled

tubing and any pipe and cable inside the coiled tubing, and sealing the bore with lateral and faceseals.

• The shear/blind ram will be designed to leave sufficient clearance between the top of the coiledtubing in the well/riser and the bottom of the ram to enable maximum circulation rates throughthe work string left in the well.

Tubing rams:• Tubing rams are required to close around the coiled tubing and seal off the annular space in the

BOP bore. Rams must be installed according to the size of coiled tubing.

Slip rams:• Slip rams shall be compatible with all ram type BOPs except the shear and shear/seal BOPs.• Slip rams are required to grip and hold the coiled tubing. They must be able to prevent up and

down movement.• Slip rams shall be of a design that minimises or avoids stress marking of the tubing.

Annular preventer (if used):• The annular preventer shall be able to close and seal off at 345 Bar (5000 psi) pressure on open

hole. The annular BOP shall operate (close) on both stationary and running objects.• The annular preventer shall be furnished with accumulators as a surge dampener for emergency

stripping of coiled tubing. This also requires annular BOP operation pressure to be regulatedfrom the control cabin as well as the remote location.

Coiled tubing equipment D-SR-005Annex E Rev. 1, January 1996


ANNEX E TERTIARY WELL CONTROL SYSTEM (SAFETY HEAD)Design:• Shear action must be possible with the maximum safe working pressure inside the safety head

body• The control system shall be completely independent and physically separated from the coiled

tubing unit.• The shear/blind rams shall be a combined shearing and blind ram capable of shearing the coiled

tubing and sealing the bore.• There shall be documentary evidence that the safety head will shear the intended size/wall

thickness of coiled tubing, including any wire or cable or multiple coiled tubing (stacked) inside,and provide sealing effect after shearing.

• An equalising valve shall be an integral feature, allowing pressure equalising around the sealelements.

Rams:• Ram actuation on the safety head will be effected by hydraulic pressure applied from one remote

control panel.

Coiled tubing equipment D-SR-005Annex F Rev. 1, January 1996


ANNEX F COMPUTERISED DATA ACQUISITION SYSTEM (CDA)The coiled tubing unit shall be equipped with a CDA system to monitor and record the followingparameters:• Time and date.• Injector load positive and negative weight.• Injector hydraulic system pressure.• Wellhead pressure.• Coiled tubing pressure (circulating pressure).• Depth.• Running/pulling speed.• Pump rate.• Number of cycles over gooseneck with corresponding pressure.

CDA system to be connected to back-up power supply.

There shall as a minimum be backup data acquisition system registering injector load, positive andnegative, wellhead pressure and coiled tubing pressure (circulating pressure).

Coiled tubing equipment D-SR-005Annex G Rev. 1, January 1996


ANNEX G MINIMUM DOCUMENTATION REQUIREDTubing injector head, well control system, valve arrangements, riser, lubricator, spools, highpressure piping and hoses, high pressure vessels:• Name of equipment.• Production number.• Name of manufacturer and supplier.• Description of design and manufacture, indicating safety factor used.• Verification of design/strength control.• Material certificates and confirmation as to where materials have been used.• Welding procedure specifications.• Statement of manufacture and inspection signed by manufacturer and surveyor/surveying

firm/body.• Report from testing including testing conditions, and information on how testing has been carried

out• Verification of design assumptions with regard to strength, carried out by an independent survey

institution. Depending on organisational independence, this function may be taken care of by themanufacturer

• Supplier’s operation and maintenance specifications, with indication of operationalcriteria/limitations.

• Marking of equipment.• Updating of items in the case of modification of equipment.• Weight and dimensions.

Coiled tubing string:

Manufactures quality control certificate and documentation:• Name of equipment.• Production number.• Name of manufacturer and supplier.• Description of design and manufacture, including safety factors used. Verification of design

assumptions with regard to strength, carried out by an independent survey institution. Dependingon organisational independence, this function may be taken care of by the manufacturer.

• Supplier’s operation and maintenance specifications, with indication of operationalcriteria/limitations.

• Material certificates, including chemical analysis, mechanical strengths (hardness, tensile andyield) and physical dimensions.

• Inspection report, including non-destructive inspection of coiled tubing body and welds,locations of all imperfections and details of drift ball test.

• Report from testing including testing conditions, and information on how testing has beencarried out. Minimum required is hydrostatic test report.

• Repair record.• Statement of manufacture and inspection signed by manufacturer and surveyor/surveying

firm/body.• Weld procedure qualifications for welds, including x-rays.• Weld log, including bias weld and butt weld locations.• (Butt-) welding procedure specifications and inspection/verification specifications.• Drying procedure used.

Coiled tubing equipment D-SR-005Annex G Rev. 1, January 1996


Additional documentation:• Log of tubing repairs, including: location of manufacturer's welds, location of section

welds/tubing cut off/added/re-used. Reason for repair.• Log of OD, ovality and wall thickness testing.• Estimated cumulative damage and remaining life time, including evaluation and location of

butt/field welds.• Operational limits for outside diameter and wall thickness.• History log of all previous jobs, including parameters influencing life time.• Documentation on receiving-QC of the coiled tubing.• Marking of equipment.• Updating of items in the case of modification of equipment.• Quality audit of the manufacturing process.• Pre-job inspection and testing documentation.

Downhole tools:

Manufactures quality control certificate and documentation:• Name of equipment.• Production number.• Name of manufacturer and supplier.• Description of design and manufacture, indicating safety factor used.• Verification of design assumptions with regard to strength, carried out by an independent survey

institution. Depending on organisational independence, this function may be taken care of by themanufacturer.

• Material certificates and confirmation as to where materials have been used.• Statement of manufacture and inspection signed by manufacturer and surveyor/surveying

firm/body.

Additional documentation:• Receiving-QC of the tool.• Marking of equipment.• Updating of items in the case of modification of equipment.• Quality audit of the maker's manufacturing process.• Inspection report.• Drawings showing internal parts/functions, overall length, maximum OD, minimum ID and

weight.• Tool description, function, maximum/minimum parameters.• Strength calculations indicating safety margins.• Operational manual/operating procedures.• Function/operational testing. This does not replace acceptance test offshore before a job.• Complete BHA drawings showing; total length, maximum OD, minimum ID, weight, position of

tools and threads.• Fishing data.

norsok d-sr-005 on coiled tubing

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