API 6A SURFACE WELLHEAD AND CHRISTMAS TREE SYSTEM

 API 6A SURFACE WELLHEAD AND CHRISTMAS TREE SYSTEM

Objective, target group and warrant.......................................................................................................... 3

1.1 Objective .............................................................................................................................................3

1.2 Target group ........................................................................................................................................3

1.3 Warrant ................................................................................................................................................3

2 General................................................................................................................................................... 4

2.1 Health, Safety and Environment (HSE) ..............................................................................................4

2.2 General.................................................................................................................................................4

2.3 Design codes .......................................................................................................................................4

2.4 Interfaces .............................................................................................................................................5

3 Product requirements for wellhead and christmas tree system ............................................................. 5

3.1 General.................................................................................................................................................5

3.2 Material requirements......................................................................................................................... 6

3.3 Wellhead system..................................................................................................................................6

3.4 Tubing hanger system .........................................................................................................................8

3.5 Christmas tree system ........................................................................................................................10

3.6 Surface exploration wellhead system.................................................................................................12

3.7 Wellhead and christmas tree system in gas lift and ESP applications................................................12

3.8 Auxiliary equipment...........................................................................................................................12

4 Qualification and test requirements .....................................................................................................13

4.1 General.............................................................................................................................................. 13

4.2 Acceptance criteria ........................................................................................................................... 14

4.3 Qualification requirements.................................................................................................................15

4.4 Factory acceptance test (FAT) requirements......................................................................................16

4.5 Stack-up test (SUT) requirements......................................................................................................17

5 Inspection, maintenance and refurbishment.........................................................................................17

5.1 General.............................................................................................................................................. 17

5.2 Track records .................................................................................................................................... 17

6 Documentation.........................................................................................................................................18

6.1 Design data book............................................................................................................................... 18

6.2 Manufacturing record data book .......................................................................................................18

6.3 Weight data sheets............................................................................................................................. 19

6.4 Data sheets......................................................................................................................................... 19

6.5 PSPIR ................................................................................................................................................ 19

6.6 Technical data book............................................................................................................................19

6.7 Additional documentation...................................................................................................................20

7 Definitions, abbreviations and modifications to previous version........................................................21

7.1 Definitions and abbreviations.............................................................................................................21

7.2 Modifications to previous version......................................................................................................22

7.3 References......................................................................................................................................... 22

App A Design basis.........................................................................................................................................................25

App B Design requirements for primary load bearing components .......................................................29

B.1 Design requirements.........................................................................................................................29

Internal

Drilling and well technology, Technical and professional requirement, TR1830, Final Ver. 1.01, valid from

2009-11-01

Page 3 of 29

Validity area: Statoil/All locations/All value chains/On- and offshore

1 Objective, target group and warrant

1.1 Objective

This document specifies Statoil requirements for surface wellhead and christmas tree systems.

The objective of this document is to provide supplementary requirements to referenced industry specifications and standards.

This document was developed to exhange experience between projects. By combining Statoil

operational experience with industry regulations in force, a gratifying level of equipment quality

and reliability will be ensured through requirements to contractors of surface christmas tree

systems. However, projects may propose alternative solutions in order to achieve the overall

objectives provided that it can be documented that the same level of safety and risk exposure is

maintained.

Project specific requirements shall not delimit the main objective of this document, and are not

covered.

1.2 Target group

The target group for this document is personnel who are involved in design, modification,

procurement and maintenance of surface wellhead and christmas tree systems.

1.2.1 Scope

The requirements, as defined in the latest edition of ISO 10423 “Specification for Wellhead and

Christmas Tree Equipment” together with all referenced codes and standards, shall be the basis

for the equipment under the scope for this document.

In addition to the specific equipment listed in ISO 10423, this specification considers the

following equipment and topics:

 Surface exploration wellhead system (mudline suspension applications) *

 Wellhead and christmas tree system in gas lift applications

 Auxiliary equipment

 Instrumentation

 Documentation

Note: *Some installations may require the use of a tie-back system. The decision to use these

components will be based on the design premises of the individual field and the type of platform

used.

1.3 Warrant

This technical and professional requirement document is valid for all Statoil operated platform

2 General

2.1 Health, Safety and Environment (HSE)

The equipment described shall meet relevant governing regulations, and Statoil’s overall HSE

goals of

 Zero harm to people or the environment

 Zero accidents or losses

 No dropped objects

The surface wellhead and christmas tree system shall be designed so as to provide for prudent

production, re-entry, well intervention and well control.

Where planned testing, operations and maintenance requires working at elevations greater than

2 meter above deck level the work areas shall be secured by permanent or easily installed

protective measures.

2.2 General

A design basis shall be established for each project. Minimum requirements for the design basis

are defined in App A Design Basis.

The equipment shall meet Statoils design basis requirements with respect to design life.

The equipment shall be designed to comply with Statoils barrier philosophy for the overall

system.

2.3 Design codes

Unless otherwise is specified explicitly, design codes shall be applied for Statoil operated wells

as follows:

 For wellhead and christmas tree equipment: ISO 10423 Specification for wellhead and

christmas tree equipment

References to other applicable rules, codes and standards can be found in section 9 References.

The christmas tree design shall comply with the requirements given by the Regulations Relating

to Design and Outfitting of Facilities etc. in the Facility Regulations and the Activities

Regulations issued by the Petroleum Safety Authority Norway (PSA).

Design requirements for primary load bearing components within scope of ISO 13628-4 and ISO

13628-7, such as subsea tie-back wellhead equipment, shall be in accordance with

requirements stated in “Subsea X-mas Tree and Completion/Workover Riser Systems” (TR0034)

(Statoil/All locations/On-and offshore).

2.4 Interfaces

Standardization regarding mechanical interfaces shall be aimed for.

Equipment: Interface should be:

Tree cap Preferrably a connector which decreases makeup

time. No loose parts. Low makeup torque. To

interface with the coil tubing well intervention

assembly and wire line intervention riser.

Weco union Weco1502 female complete with blind plug

Christmas tree ring grooves Face-to-face

Wellhead connector Connector which decreases makeup time. No

loose parts. Low makeup torque. Hub profile. To

interface with riser, BOP and christmas tree

Instrumentation Via bulk head plate, Autoclave MP anti-vibration

fittings for hydraulic LP and HP-systems, and

compression fittings for process instrument

hook-up

Tubing hanger pup joint Vam Top

A Annulus valves API flanges

B Annulus valve API flanges

C Annulus valve API flanges

Test ports 9/16” autoclave

Table 2-1

3 Product requirements for wellhead and christmas tree system

3.1 General

The technical and functional requirements applicable to the wellhead and christmas tree

equipment will be covered in this section. All valves shall conform to the requirements of ISO

10423. The gate-to-seat and seat-to-body shall have positive metal-to-metal sealing. The

bonnet seal shall be metal-to-metal. All valves shall be provided with a backseat with metal-tometal

sealing. Gates and seats shall be hard faced.

The requirements in ISO 10423 Annex D “Recommended flange bolt torque” and Annex G

“Design and rating of equipment for use at elevated temperatures” shall be normative.

On manual valves, the number of turns fully opens to fully closes the valve shall be stated on the

valve data plate and stamped on the hand wheel such that it is legible to the operator.

The christmas tree assembly, surface wellhead assembly, valves, loose flanges and connectors

shall have coating in accordance with NORSOK M-501, coating system no. 1, RAL 9002. Bolts

shall be masked prior to painting.

Non-metallic primary seals such as stem seals, and all non-metallic secondary sealing

production effluent, shall be resistant to the rapid gas decompression requirements of NORSOK

M-710 and compatible to the fluid environment.

The wellhead design shall provide two sealing surfaces for the two independent seals of the

tubing hanger, one located in the multi-bowl or tubing head, and one located in the christmas

tree.

All test, injection, bleeder and grease ports shall be clearly marked.

3.2 Material requirements

The material requirements shall be in accordance with ISO 10423. The materials shall be

compatible with the materials selected for other production equipment (tubing, manifold) and be

according to the material recommendations found in TD0019.

For sour service applications, all metallic materials which are in contact with the well fluids shall

conform to the requirements of NACE MR-01-75.

The manufacturer shall ensure that the materials used are compatible with regard to galvanic

corrosion, and that the system is designed to provide an overall resistance against corrosion.

Crevices and dead ends where water or solids or deposit may be trapped shall be avoided.

All seal grooves shall be overlaid with nickel base Alloy 625. Weld overlay on seal surfaces shall

be project specific. Weld overlay is not accepted on any load bearing surfaces.

3.3 Wellhead system

The wellhead shall be preferable of a compact type with either

 A one piece multi-bowl housing comprising the casing head and the tubing hanger, or

 A split type with the casing head housing and a tubing head as the upper housing

as shown by the principles of figure 1. Both designs require starter head housing, and will be

project specific.

All hangers should be internally locked. Exterior tie-down bolts should be avoided.

The wellhead system shall have provisions for installation of intermediate and production

casing, casing-hangers, emergency hangers and required pack-offs with full BOP protection or

at least two (2) tested barriers are established at all times.

The tubing hanger and wellhead shall be prepared for eight (8) feedthroughs for downhole

signals to pass through the tubing hanger and wellhead.

The wellhead shall be equipped with test ports for integrity testing of all system seals from the

exterior of the wellhead.

The wellhead- and conductor design shall allow for mud and cement return without damaging

sealing surfaces.

Conductor analysis shall be performed to ensure overall structural strength, integrity and

operability of well systems under the scope of this document. A conductor analysis shall

consider drilling, production and workover operations, when determining appropriate load

cases. The following issues are relevant to the conductor analysis:

 Effects of landing internal casing strings on the conductor

Fig. 1

Typical split type wellhead assembly nomenclature

3.3.1 Starter head housing

In terms of casing head housing being installed on the conductor casing by mechanical lock,

thread or weld and seal considerations, will be project specific due to local operational

conditions such as shallow gas and thermal expansion.

The annulus outlets shall comprise of API flanged valves, blind flange and pressure gauge and

one recessed blind flange, equipped with valve-removal threads as per ISO 10423, Annex L.

It shall be provided with two (2) API studded outlets prepared for valve-removal plugs for access

to the conductor casing x intermediate casing (A annulus) and, if required, communication with

the LP riser. One outlet must be angled as close to a vertical position as possible (minimum 45

degrees) in order to allow use of “spaghetti tubing” for top-up grouting, if required.

Projects shall address concerns around shallow gas. In case of shallow gas, the A annulus shall

be sealed and capable of holding nitrogen charge of 500 psi above the mud column.

3.3.2 Multi-bowl housing, casing head housing and tubing head housing

The wellhead housing profile of the multi-bowl or casing head/tubing head housing is prepared

for suspending and packing off the necessary number of casing strings and one tubing string.

The upper connection of the tubing head shall meet the requirements of API 6FB. The

production annulus valves shall meet the fire resistant requirements for API 6FA (manual valves)

or API 6FC (actuated valves). All wellhead components shall be capable of handling the

compression and thermal expansion forces acting on the system. Both upper and lower

connection of the multi-bowl or tubing head housing shall be designed for quick and easy

installation. The lower connection may be installed by a mechanical lock and seal.

The number of ports through the multi-bowl or tubing head housing provided for continuous

control lines, electrical lines and fiber optical lines are project specified. The termination shall be

of a fire resistant arrangement.

All annulus shall have API studded outlets. The valve-removal preparations and plugs shall

conform to the requirements in ISO 10423, Annex L. For casing heads that are run through the

diverter riser, the outlets shall initially be fitted with flush valve-removal plugs. Annulus access

during production shall be provided via a ½” NPT port and a gauge cock located in one of the

wellhead valve removal (bull plugs) plugs. All other valve-removal plugs shall include fittings for

bleed-off.

Drill cuttings injection operation during the drilling phase, will affect casing hanger wall

thickness or hard facing of impact of the casing hanger.

The internal diameter bore of the housing shall accept all drill bit sizes with wear protector

installed.

Casing hangers shall be installed with full BOP protection. Flow by ports in the casing hangers

shall be designed such that the possibility of plugging during circulations operations is

minimized.

It shall be possible to retrieve the wellhead housing after installation.

All flanges shall have bleeder arrangement.

3.3.3 Emergency equipment

All requirements applicable for the primary equipment shall also be valid for the contingency

equipment including emergency hangers.

3.4 Tubing hanger system

3.4.1 General

The tubing hanger system consists of the following main components:

 Tubing hanger assembly (tubing hanger body with pup joint, lockdown ring, seal and seal

assemblies, pipe plugs and fittings, protector sleeve etc.)

 Tubing hanger plug

 Tubing hanger running and retrieving tool

The tubing hanger minimum capacities shall cater for all tubing string and A-annulus induced

loads during all phases of well service life. The tubing hanger shall be run with the tubing

through the BOP stack and riser. The hanger shall either land on a positive shoulder, or the

casing hanger below,

and be locked in place with an integral mechanical device. Tie-down bolts should be avoided.

The tubing hanger shall have extended neck with metal to metal seals.

Annulus seals or pack-offs shall be of metal-to metal design or certified for the life of the field

or at least 20 years.

The tubing hanger shall be designed such that correct landing, locking and retrieval of the

tubing hanger is not obstructed or prevented by debris.

The tubing hanger shall be supplied made up to a Vam Top product line pup joint with a thread

protector. Pup-joint length, type of thread and nominal weight will be project specific. The

length of the tubing hanger pup-joint shall allow for make up to the tubing string offshore by

use of a standard rig tubing tong. The make-up torque shall be as required for the actual thread

type and pressure tested. Make-up process and evaluation of process shall be according to

connection design owner’s recommendations, and be evaluated and certified by fully competent

personnel. The make-up torque and pressure test shall be documented. The tubing hanger body

shall have sufficient material for at least one tubing thread re-cut. The pup-joint material shall

be according to “Best Practice for the Selection of Materials for Downhole Equipment” (TD0021).

Pup joints shall be manufactured from Company supplied goods, and be produced and certified

according to “Downhole Tubular Accessories; Crossovers, Pup-joints and Cross-over Pup-joints”

(TR0061).

Number of vertical ports for continuous control lines, electrical lines and fiber optical lines,

sealed with bored through fittings top and bottom, will be project specific. All ports shall have a

side outlet to enable testing of the top and bottom fittings. The design of the tubing hanger and

running tool shall be such that pressure can be maintained on the control lines during all stages

of installation. All unused ports shall be plugged.

The tubing hanger shall be installed with full BOP protection.

The bore design shall allow for operations to take place through the tubing hanger.

The length of the transportation basket shall accommodate tubing hanger, tubing hanger pup

joint and tubing hanger running and retrieving tool. The transportation basket shall be equipped

with certified lifting eyes and fork lift pockets.

The tubing hanger seals shall have protection to prevent damage during transportation. The

protection shall enable inspection of seals in the transportation basket.

3.4.2 Tubing hanger plug

The internal bore of the tubing hanger shall have a profile for setting a tubing plug and BPV. The

tubing plug design shall eliminate the need for running and installing a test dart to be able to

test the christmas tree above the plug. It shall also be able to hold pressure from above and

below without installing a test dart. The possibility to equalize pressure below the tubing plug

prior to retrieving plug from tubing hanger bore shall be present. The plug shall have the

potential to be run on both hydraulic lubricator tool and manually on rod.

3.4.3 Tubing hanger running and retrieving tool

It shall be possible to pressure test the tubing hanger seals prior to releasing the tubing hanger

running and retrieving tool. The THRT shall ensure hydraulic communication with the DHSV

during installation.

3.5 Christmas tree system

The christmas tree includes lower manual master, upper hydraulic master, manual swab, manual

kill wing and a hydraulic wing valve. In addition, the christmas tree may have one extra wing

valve. The christmas tree shall be as compact as possible. The dimensions of the christmas tree

shall allow for passage through the platform hatch opening. It must allow for installation of BPV

or tubing hanger plug without interference with lower master valve. The christmas tree system

shall be protected from falling objects.

A horizontal platform christmas tree may also be used, provided that the potential number of

workover completions and wireline interventions are considered. In case of TTD&C operations,

protective sleeves shall be designed.

Lower manual master shall be of fire resistant design according to API 6FA. Upper hydraulic

master shall be of fire resistant design according to API 6FC. Entrapped cavity pressure between

upper and lower master valves shall be released upstream in case of fire.

All flanges shall be face to face. All connections associated with a 15K psi WP (and above)

christmas tree shall have double seals. This does not include the production wing valve/flowline

interface and kill wing valve.

The hydrocarbon production christmas tree, as defined in TD0019 8.2, shall be fitted with a ½”

valve for MEG injection located between the production wing and master valves. The system

shall incorporate an integral check valve which shall be serviceable without shutting down

production.

All instrumentation ports shall be flanged and include a block and bleed valve with ½” NPT

outlets for both instrumentation and bleed line.

The christmas tree body shall preferably be a single piece forged block.

A flanged crossover to Weco 1502 female union with end plug and bleed fittings shall be

installed on the kill wing end connection.

The christmas tree shall be painted prior to hydrostatic testing to eliminate ingress of shot

blasting grit after testing.

All test ports, bleed ports or other valve body penetrations must be equipped with fittings or

plugs with metal-to-metal sealing. The fittings or plugs must include the possibility of pressure

check or bleed off without removal of any fitting or plug parts and without the use of a stinger.

The primary sealing seat shall be replaceable. If the christmas tree is overlaid with nickel base

Alloy 625, test ports shall also be overlaid.

Lower master and hydraulic master shall include wire cutting gates.

PWV

UMV

LMV

SV

KWV

P

Figur 3-1 Typical conventional

christmas tree layout

3.5.1 Christmas tree cap

The tree cap shall include a blind hub with bleed for wireline lubricator and coiled

tubing/snubbing hookup. The tree cap shall have a low weight connector or remote split clamp

design such that heavy lifts and loose parts are eliminated to meet Statoil’s overall HSE goals.

Disconnection of the tree cap shall be safe and efficient in order to minimize use of rig time.

3.5.2 Actuators

All actuators shall be fail-safe close.

The hydraulic operated production wing and master valve shall be capable of closing against full

flow within 30 seconds. A quick dump valve may be used to meet this requirement.

The actuator operating pressure shall be sufficient and the hydraulic master valve shall to be

capable of cutting all slick lines, braided wires and logging cable run through the actual

christmas tree. Each project shall maintain Statoils barrier philosophy.

The actuator spring housing shall have drain plugs facing downwards.

Each actuator shall be equipped with two limit switches. All limit switches shall be intrinsically

safe, zone one (1) explosion proof, Namur type and shall be suitable for EEx circuits and

terminated in a junction box. The hydraulic operated production wing and master valve

including limit swithches shall be tagged with an instrument tanumber in accordance with the

specific project numbering system.

Hydraulic actuators shall be supplied flushed to SAE AS4059E/NAS 1638 Class 6 cleanliness.

The christmas tree shall be supplied with certified lifting and suspended in a balanced mode for

installation purposes.

The actuators shall be painted prior to hydrostatic testing to eliminate ingress of shot blasting

grit after testing.

3.5.3 Christmas tree instrumentation and local instrument panel

This section defines christmas tree field instrumentation and control room operated master-,

wing, downhole safety (SCSSV) and annulus (ADV) valves. Instrumentation design is considered

project specific. The following requirements shall apply:

Instrumentation interface shall be via a bulkhead plate. The umbilical shall be mounted directly

to the bulkhead plate. The plate shall be supported to the christmas tree. The plate shall be

made in SS316 and be 8-10 mm thick.

 Hydraulic instrument tubing to SCSSV and ADV (HP-system), in addition to mater- and wing

(LP system) shall be installed with Autoclave MP anti-vibration fittings/tubing

 Instrument tubing material shall be in accordance with “Guideline for selection of instrument

tubing and clamps for offshore and onshore plants” (TD0101)

 Wellhead control panels shall have electric/hydraulic EExm certified solenoide valves

3.6 Surface exploration wellhead system

The surface exploration wellhead equipment shall be according to ISO 10423, PSL 3 and PR 2

requirements. The additional requirements of PSL 3G, will be project specific.

The “slip and seal” wellhead, which requires removal of BOP in order to install the casing slip

and seals, is not acceptable.

3.7 Wellhead and christmas tree system in gas lift and ESP applications

The relevant wellhead and christmas tree equipment associated with gas lift applications shall

meet the requirements of ISO 10423 PSL 3G. Casing hanger and tubing hanger seal assemblies

shall have metal-to-metal design equipped with test fittings.

In case of ESP wells, the system shall allow sufficient space for electrical ESP penetrators.

3.8 Auxiliary equipment

The manufacturer shall provide all necessary auxiliary equipment and accessories and services

for transportation, installation and seal surface protection during drilling, washing/cleaning,

testing or completion operations. This includes Skids, frames, racks and baskets. Complete set including back-up required for installation.

 Installation tools, test tools and wear bushings. Complete set including back-up required for

installation.

 Accessories, such as BPV including installation tool, tubing hanger plug, lubricator, all test

plugs and x-overs.

 Completion container. Complete with all required tools in conjunction with completion of

wellhead and christmas tree.

 Lifting equipment in accordance with the applicable specification and standard. This includes

lifting certificates for all lifting appliances, lifting eyes, lifting lugs, wires, chains and slings.

4 Qualification and test requirements

4.1 General

The qualification and test requirements for all equipment covered by this document, ref. Section

1.3 Scope, shall be in accordance to ISO 10423 Annex F PR2 together with the supplementary

requirements described in this section.

All equipment or components that represent a new design, new technology or use of existing

solutions for other conditions than previously used- or qualified for, shall be identified and

qualified for the intended use. Ref. “Technology Qualification” (WR1622) and “Execution of

technology qualification within drilling, well and production technology” (GL0046) .

For qualification of equipment, the requirements in ISO 10423 Annex F “Performance verification

procedures” shall be normative, and the equipment shall meet performance requirement level

two (PR2).

All analyses, calculations, tests and comparisons required to qualify the equipment/component

shall be defined and assessed. This shall include requirements from all relevant codes,

standards and Statoil requirements. All qualification work shall be documented and verified by a

third part or an independent surveyor.

The purpose of the qualification is to simulate operational conditions in order to prove the

quality and reliability of the design, and to identify design limitations. To avoid operational

failures the operational limitation shall be established and therefore some of the tests shall be

continued until failure.

Qualification shall include design calculations and full scale testing. Extrapolation of test results

is not acceptable. Interpolation of test results may be used in cases where calculation methods

provide reliable results, e.g. for failure modes such as leak tightness, preload (bolt, hub-face)

and friction.

For new systems or modification of existing systems, structural qualification testing is required

to demonstrate that the local and global failure modes are acceptable. However, if failure

capacities can be documented by other means, structural failure tests for components may be

excused.

As a minimum, PSL 3 shall be specified for surface wellhead and christmas trees. However, all

equipment or components that may be exposed to gas as part of their service (gas producer

well, gas lift well) shall be tested with gas at the specified working pressure and temperature

range during the qualification programme. Gas testing shall be performed in accordance with

ISO 10423, 7.4.9.5, PSL 3G.

A detailed qualification and test program for the overall supply shall be prepared according to

the relevant codes and standards, and shall include all additional requirements specified in this

document. The program shall include all tests being a part of the qualification program as well

as factory acceptance tests (FAT) specified in ISO 10423. The purpose of FAT and SUT (stack-up

test) and related acceptance criteria shall be clearly stated. The test program and procedures

shall be issued and available for review prior to start of the test. Test reports shall be issued as

soon as the test has been performed. All equipment shall be delivered in “as new” condition.

Complete assemblies shall be qualification tested. Individual seals as well as complete seal stack

assemblies shall be subjected to the qualification program. Qualification performed on parts of

the complete assembly will not exclude complete assembly testing.

The method of installation can influence the overall performance, thus the component shall be

installed by aid of the actual offshore installation tools and procedure as a part of the

qualification test.

The product tolerances shall be in accordance with ISO 10423 Annex F.1.4.3. The worst-case

conditions for dimensional tolerances shall be identified by means of a stack-up drawing.

If necessary, a volume reducer rod shall be installed during pressure tests.

If for any reason a test is halted and any part of the test set-up has been altered or

disassembled, the test shall be cancelled. Continuation of a cut off test requires that the test

program is repeated from start.

The design life shall not be reduced due to extensive operation of the system during fabrication

and tests. New seals shall be installed as applicable.

4.2 Acceptance criteria

The acceptance criteria in this section are applicable to qualification testing, FAT and SUT.

4.2.1 Hydrostatic leak- and pressure test

The acceptance criteria and hold period for hydrostatic leak- and pressure testing during

qualification testing shall be according to ISO 10423 Annex F.1.6 and Annex F.1.10 respectively.

The acceptance criteria and hold period for hydrostatic leak- and pressure testing during FAT

and SUT, shall be according to ISO 10423 7.4.9.5.

4.2.2 Gas leak- and pressure test

The acceptance criteria for all gas leak- and pressure testing of equipment shall be:

1. At ambient temperature:

 No visible bubbles. If necessary, a camera shall be installed to capture bubbles outside

field of view.

According to ISO 10423, 7.4.9.5 PSL 3G for qualification testing, FAT and SUT

2. Temperature testing above and below ambient temperatures:

 No sustained bubbles. If necessary, a camera shall be installed to capture bubbles outside

field of view.

 According to ISO 10423, 7.4.9.5 PSL 3G for qualification testing.

The assembly shall be placed such that any leakage can not be trapped in cavities or dead ends.

The hold period for gas leak- and pressure testing shall be 1 hour.

For all gas testing, a leak detection system shall capture all gas that passes though a seal and

collect the gas in a container for measuring the volume.

4.3 Qualification requirements

4.3.1 Fire testing

The following equipment shall be covered by the fire resistant envelope:

 Wellhead connector (end connection)

 Upper actuated master valve

 Lower manual master valve

 ESV (inner annulus valve)

 Control line exit block inlet in wellhead

The specified equipment shall meet the requirements of API 6FA, 6FB, 6FC and 6FD.

4.3.2 Seals

Metallic seals shall be qualified in accordance with ISO 10423 F.1.11.

Non-metallic materials and manufactures shall be qualified in accordance with NORSOK M-710

and qualified in accordance with ISO 10423 F.1.11 and F.1.13.

Non-metallic primary seals such as stem seals, and all non-metallic secondary sealing exposed

to production effluent or gas, shall be resistant to the rapid gas decompression requirements of

NORSOK M-710 and compatible to the fluid environment.

Installation of the seals for the test shall simulate actual installation conditions and the test

fixture shall simulate real behavior including thermal effects and axial movements.

The seals shall be qualified for intended use, e.g. leak tightness from both directions where

applicable. The individual seals as well as the complete seal arrangement (primary and

secondary seals) shall be qualified.

4.3.3 Shear test requirements

All valves with cutting requirements shall undergo shear tests to demonstrate the cutting and

sealing performance as part of the qualification program.

The shear test of each specimen shall be performed with no WP in the bore. Alternatively the

shear test can be performed without pressure, provided that it can be documented that there is

sufficient force available to shear with maximum WP in the bore.

Each shear test shall be followed by a successful leak test to minimum and maximum WP. The

test medium and duration shall be the same as the valve is being qualified for.

The shear test qualification is accepted when the valve has performed a successful shear test of

all specimens according to the table below. In case that the shear test fails on one or more of

the test specimens, the shear test on the failed test specimen shall be successfully repeated

three times in order to be accepted.

If the design of the valve is changed, the complete shear test requirements shall be repeated.

Each shear test can be performed independently of each other and it is acceptable to re-dress

the valve between the shear tests.

The material grade and wall thickness (when applicable) of all test specimens shall be recorded.

Shear test requirements

Equipment Test specimen

Hydraulic upper master valve  1ea 0.125” slickline (neutral)

 1 ea 7/32” braided wire/electrical cable

(neutral)

 1 ea 5/16” braided wire/electrical cable

(neutral)

 1 ea 7/16” braided wire/electrical cable

(neutral)

Table 4-1

4.4 Factory acceptance test (FAT) requirements

4.4.1 General

Equipment covered by this document, ref. Section 1.3 Scope, shall be subjected to a FAT.

FAT testing shall comply with ISO 10423 PSL 3 or higher. All systems, or components thereof,

that are expected to see gas service, shall be tested with gas at working pressure during the FAT

program in accordance with ISO 10423 PSL 3G. The holding period for all gas tests shall be 1

hour.

If more than one christmas tree is manufactured with PSL 3G requirements, the first fully

assembled christmas tree shall be submerged in fresh water and tested with nitrogen gas as a

part of the FAT. The purpose of this test is to verify the quality of the product and to

demonstrate no leakage to the surroundings. The duration of the test shall be one (1) hour. The

test shall normally be performed with valves in open position. During the test the actuators shall

be cycled (close – open) at intervals of 4 hours during the test period, and hold period shall be

at least 1 hour after each cycling operation.

Each project may choose to test more than one christmas tree.

Unused hydraulic-, electric- or fiber optic ports in the TH and XT shall be plugged and tested to

design pressure in flow direction as part of the FAT.

4.5 Stack-up test (SUT) requirements

4.5.1 General

A complete stack-up test (SUT) shall be performed with the complete equipment assembly,

i.e.multi-bowl or split casing head, tubing head, hangers and pack-offs, christmas tree

assembly with instrumentation panel. During the SUT all running and retrieval tools associated

with installation, drilling and completion shall be tested, including the BPV, LP and HP riser, WL

lubricator and VR plugs. Pack-offs, valves and connections shall be tested at the appropriate

working pressure with the appropriate fluid medium.

The actual equipment intended for the field shall be used.

Any discrepancies found during the test shall be implemented in the installation procedure.

5 Inspection, maintenance and refurbishment

5.1 General

Statoil and manufacturer shall establish type and frequency of inspections. Any faulty/damaged

equipment shall be reported immediately to Statoil with a view to repairs being carried out prior

to its next usage. An inspection report shall include an assessment of the specified component

and a plan of repair and/or remanufacture, if required.

A preventive maintenance service program shall be established to minimize wear and damage to

extend the useful life of the equipment. Maintenance of equipment shall be broken down into

three types as follows:

 Routine maintenance – Performed each time equipment has been used, ie running tools.

 Storage maintenance – Performed whenever equipment is to be removed from service for any

lengthy period.

 Periodic maintenance – Performed at intervals as specified by Statoil and manufacturer.

It shall be documented that all components and systems that will be used are in satisfactory

condition, and will remain so, with sufficient margins, during the planned operation. This

implies that all components shall have track records with complete documentation of

manufacturer, date of manufacture, operation and maintenance manual, type and component

approval documents, operation track log, and inspection/maintenance track log.

Reconditioned surface wellhead and christmas tree equipment shall meet the requirements of

ISO 10423 Annex J and TR1830.

5.2 Track records

There shall be a system for recording all inspections, maintenance, repairs and other events of

relevance to structural safety, throughout the service life, until taken out of service. The

recorded data shall be available to authorized personnel whenever needed.

6 Documentation

This section specifies the document and drawing requirements for surface wellhead and

christmas tree equipment, and is supplementary to ISO 10423. The information should be

prepared in electronic format, but must also be available in hard copy format. The information

shall be submitted to Statoil, with the exception of “Manufacturing record data book”. The

requirements are specified in individual lists under the following headings:

 Design data book

 Manufacturing record data book

 Weight data sheet

 Data sheets

 PSPIR

 Technical data book

 Additional documentation

6.1 Design data book

The design data book shall be suitable for review prior to fabrication and shall comprise:

No Drawing and document description

1 A complete list of the christmas tree and wellhead equipment.

2 Complete bill of material as applicable to the individual components arranged

by major subassemblies.

3 Descriptive text to gain a full understanding of the purpose of and the design

philosophy applied to each component and major subassemblies.

4 Design specifications, including environmental data, all relevant design loads,

fluid data and information on corrosion control.

5 Design analysis/calculations or test data verifying the design of all components,

including allowable external loading with full working pressure and BOP weight,

all hanger loads and loads between load carrying members with no internal

pressure and with full working pressure.

6 Complete information and data on all interfaces/connections, such as flanges

and hubs. This includes bending moment capabilities and load carrying

capacities of all connections throughout the assembly.

7 Drawing giving dimensions and details for evaluation of the design.

8 Welding procedure specifications.

9 Fabrication specifications including test and NDT procedures (giving type and

extent, procedures for heat treatment, weld overlays, bolt pre-stressing etc.)

Table 6-1

6.2 Manufacturing record data book

The supplier shall keep the manufacturing record book. The information shall not be submitted

to Statoil. The manufacturing record book shall as a minimum contain the following information:

No Drawing and document description

1 Assembly drawings (signed as built)

2 Certificate of compliance with contract requirements, signed by

No Drawing and document description

tenderer/contractor

3 Complete FAT and SUT reports with records and results including summary

statement

4 Component qualification documentation

5 Damage report

6 Dimensional test reports including thread gauging

7 Fabrication welding and weld repair reports

List of weld specifications

List of welders and certificates

8 Functional/performance test reports

9 Heat treatment procedures

10 Heat treatment reports/calibration certificate

11 Material specifications

12 Material certificates shall comply with EN 10204 - 3.1 for all metallic materials

and containing parts

13 Material and corrosion evaluations

14 Mechanical test reports

15 NDT procedures

16 NDT reports and NDT operators qualification

17 Pressure test procedures

18 Pressure test reports/calibration certificate

19 Procedure for equipment calibration

20 Reports stating non-conformance with Statoil requirements

21 Statoil representative release note

22 Welding procedure specifications and qualifications

23 Weld repair procedures

Table 6-2

6.3 Weight data sheets

Weight data sheets should be included in the documentation.

6.4 Data sheets

The data sheets shall contain essential information on the equipment such as bore size,

pressure rating and type of lubricant.

6.5 PSPIR

PSPIR shall be provided for each project. This specification does not state any numbers for

spares, or which spare components that shall be provided in any given system.

6.6 Technical data book

The technical data book shall represent the complete documentation package of the product. It

shall contain the following three separate sections:

 Section 1: General product description

 Section 2: Installation procedures

 Section 3: Operation and maintenance procedures

A complete and detailed index to simplify retrieval of information shall be included. A search

system should also be available. The content should be organized by equipment items or groups

as follows:

 System description

 Surface wellhead

 Tubing hanger

 Christmas tree

 Christmas tree system valves (including all valves)

 Complete interface information

6.6.1 Section 1 – General product description

General product description should as a minimum include the following information:

No Drawing and document description

1 Allowable external loading with full working pressure and BOP stack weight,

and all hanger loads with no internal pressure and with full working pressure

2 Assembly and disassembly procedures

3 Assembly drawings, item drawings and/or detailed drawings with general

equipment dimensions and item numbers with cross references to the bill of

material

4 Bill of materials including material designations

5 Complete equipment description

6 Complete interface documentation and drawings

7 FAT procedures and SUT procedures

8 Hydraulic/electrical schematics and line routing diagrams

9 Procedure for preservation, storage and onshore testing (if applicable) of

equipment before offshore shipment.

10 Stack-up assembly drawing

Table 6-3

6.7 Additional documentation

During the operation phase, the manufacturer shall keep updated track-records of installed

equipment. P/N and S/N shall be linked to the actual well slot number and logged electronically.

This applies to the following equipment:

 Christmas tree assembly

 Wellhead assembly

 Tubing hanger assembly

 Casing hanger assembly

 Seals and seal assemblies

7 Definitions, abbreviations and modifications to previous version

7.1 Definitions and abbreviations

For the purpose of this document, the following abbreviated terms apply:

Abbreviation: Means:

BOP Blow Out Preventer

BPV Back Pressure Valve

CIV Cavity Isolation Valve

DCI Drill Cuttings Injection

DHSV Down Hole Safety Valve

DNV Det norske Veritas

DP Drillpipe

ESP Electrical Submersible Pump

ESV Emergency Shut Down Valve

FAT Factory Acceptance Test

HP High Pressure

HSE Health, Safety and Environment

HXT Horizontal christmas tree

KV Kill Valve

LMV Lower Master Valve

LP Low Pressure

LMV Lower Master Valve

MD Measured Depth

MEG Mono Ethylene Glycol

MIV Methanol Injection Valve

MSL Mean Sea Level

N/A Not Applicable

NACE National Association of Corrosion Engineers

NDE Non Destructive Examination

NDT Non Destructive Testing

NPD Norwegian Petroleum Directorate

OEM Original Equipment Manufacturer

OMM Operation and Maintenance Manual

OWC Oil-Water Contact

P/N Part Number

PR Performance Requirement

PSPIR Parts, spare parts and interchangeability record

PSL Product Specification Level

PWV Production Wing Valve

RT Running Tool

SCSSV Surface Controlled Subsea Safety Valve

SIV Scale Inhibitor Valve

S/N Serial Number

SWAB Swab Valve

SUT Stack Up Test

TC Tree Cap

TTD&C Through Tubing Drilling and Completion

TH Tubing Hanger

Abbreviation: Means:

THRT Tubing Hanger Running Tool

TR Technical Requirement

TVD True Vertical Depth

UMV Upper Master Valve

WL Wireline

WP Working Pressure

Table 7-1

7.2 Modifications to previous version

This document replaces “Procurement of Surface Christmas Tree System”, located on the BOB

Extranet.

7.3 References

7.3.1 Levels of regulations and norms

In case of conflict between any of the Statoil governing documents, the conflict shall be clarified

with the process owners. In case of Statoil requirements being more stringent than authority

regulations, Statoil requirements shall prevail. A contract shall embrace the following:

Acts

Authority regulations

Guidelines

Standards

Statoil internal requirements

Contract

7.3.2 Act, authority regulations and guidelines

Doc.no Title

Doc.no Title

Act 29 November 1996

No. 72

Petroleum activities act

Framework HSE Regulations relating to health, environment and safety

in the petroleum activities (including guidelines)

Management Regulations relating to management in the petroleum

activities (including guidelines)

Information duty Regulations relating to material and information in the

petroleum activities (including guidelines)

Facilities Regulations relating to design and outfitting of

facilities etc. in the petroleum activities (including

guidelines)

Activities Regulations relating to conduct of activities in the

petroleum activities (including guidelines)

7.3.4 Standards and specifications

Doc.no Title

API RP 2R Recommended Practice for Design, Rating, and Testing of Marine

Drilling Riser Couplings

Doc.no Title

Riser Systems

API 6FA Specification for Fire Test for Valves

API 6FB API Specification for Fire Test for End Connections

API 6FC Specification for Fire Test for Valves with Automatic Backseats

API 6F1 Technical Report on Performance of API and ANSI End Connections

in a Fire Test According to API Specification 6FA

API 14D Specification for Wellhead Surface Safety Valves and Underwater

Safety Valves for Offshore Service

API 16A Specification for Drill Through Equipment

API 17D Specification for Subsea Wellhead and Christmas Tree Equipment

ASME VIII Rules for Constructions of Pressure Vessels

ISO 10423 Drilling and production equipment – Wellhead and Christmas tree

equipment

ISO 13533 API 16A

ISO 15156 Materials for use in H2S-containing environments in oil and gas

production

ISO 9001 Quality management systems - Requirements

NORSOK

M-501

Surface preparation and protective coating

NORSOK

M-710

Qualification of non-metallic sealing materials and manufacturers

Table 7-4

7.3.5 Other

Doc.no Title

IP-The

institute

of

petroleum

Guidelines for the analysis of Jackup and Fixed Platform and Well Guidelines for the analysis of Jackup and Fixed Platform and Well

Conductor Systems

API RP 2Q Recommended Practice for Design and Operation of Marine Drilling

App A Design basis

A design basis shall be established for each project. The purchasing guidelines as specified in

ISO 10423 annex A shall be normative and shall form the foundation when defining the design

basis. In addition, functional requirements shall as a minimum be considered/defined in the

design basis.

This section contains general information and field data which constitutes the design basis

relevant to the manufacturer, such as

 Field and reservoir

 Auxiliary equipment

 Interfaces with other equipment

 Information on drilling equipment

 Operational data

This information should be submitted along with the technical specification to the tenderer

and/or contractor.

Field data:

Description: Data:

Field location

Number of wells planned

Operator

Field and reservoir

background

Weather deck hatch

dimensions

Operational modes

overview

Well slot spacing

Drilling equipment

interface

Flowline layout

Table 7-6

Platform and equipment key data:

Description: Data:

Type of platform

Number of wells planned

Number of wellheads / christmas trees incl.

back-up

Type of christmas tree

Production bore diameter

Handling arrangement, overhead cranes

Weather deck hatch dimensions

Downhole equipment / Diacs requirements

Description: Data:

Flowline layout

Table 7-7

Reservoir data:

Description: Data:

Reservoir type

Water depth [m]

H2S content [ppm or mole %]

CO2 content [ppm or mole %]

HCO3 content [ppm]

Chlorides [mg]

Sulfur

Water or bring pH

Inhibitor type

Oil/condensate production rate [Sm3/d]

Gas production rate [Sm3/d]

Sand and water production rate [Sm3/d]

Water production rate [Sm3/d]

Max./Min. operating temperature [oF or oC]

Shut-in pressure [psi or MPa]

Equipment rated working pressure [psi or

MPa]

Anticipated years of service

Table 7-8

Drilling rig:

Description: Data:

Type

Capacity

Rotary info

Table 7-9

Depths and elevations:

Description: Data:

Drill floor elevation (MSL) [m]

Water depth (MSL) [m]

Max. target depth [m]

Max. target displacement [m]

Max. hole angle [o]

Drill floor elevation [mm]

BOP deck elevation [mm]

Weather deck elevation [mm]

Cellar deck elevation [mm]

Diverter and BOP stack elevations:

Description: Elevation and/or location:

Diverter stack, bottom connection elevation

[mm]

Diverter riser [mm]

Diverter outlet spool [mm]

BOP stack, bottom connection elevation

[mm]

BOP HP riser length [mm]

Snubbing stack location

Coiled tubing units locations

Weather deck elevation [mm]

Wireline units elevation and location [mm]

Table 7-11

Diverter key data:

Description: Data:

Diverter brand

Diverter nominal size [in]

Diverter pressure rating [psi]

Diverter system weight [ton]

Diverter riser bottom connector

Table 7-12

BOP stack key data:

Description: Data:

BOP stack brand

BOP stack nominal size [in], one or two

stack system

BOP stack pressure rating [psi]

BOP system weight [ton]

BOP bottom connector

BOP adaptor bottom connection

BOP riser assembly

Connector to wellhead

Table 7-13

Conductor, casing and tubing program:

Outer

diameter

[in]

Weight

[lb/ft]

Grade Connections Interval

TVD

[m]

Drift

diameter

[in]

Table 7-14

Maximum setting depth and dry weight of tubulars:

Description Depth MD [m] Dry string weights in

air [tons]

Table 7-15

Drill bit sizes:

Description Drill bit size [in]

Table 7-16

Drill pipe:

Size [in] Weight

[lb/ft]

API Grade Thread OD tool

joint [in]

Table 7-17

App B Design requirements for primary load bearing components

B.1 Design requirements

This section is intended to be used as a means to ensure that applicable design principles, loads

and load effect have been utilized to make certain that the entire anticipated life of service for

the equipment is taken into consideration.

Finite element analysis shall be used extensively to assure that the equipment under the scope

of this document meets ISO 10423 and ASME Section VIII allowable stresses at the load cases for

makeup, working and test pressures during installation and production phase. All internal and

external load cases shall be identified.

Conductor analysis shall be performed.

Accommodations for thermal expansion and contraction of the tubing and casing shall be

provided at the surface in the wellhead assembly.