Wellhead Requirements Vol 5

7/24/2019 Wellhead Requirements Vol 5

1/27

Minimum WellheadRequirements

Industry Recommended Practice(IRP)Volume 5 - 2002

Sanctioned

2002-06


2/27

This document as well as future revisions and additions are available from:

The Petroleum Industry Training Service (PITS)

1538 25 Avenue NECalgary, Alberta

T2E 8Y3

Phone: (403) 250-9606Fax: (403) 291-9408

Website: www.pits.ca


3/27

Table of Contents

5 Minimum Wellhead Requirements........................................................ 3

5.0 Acknowledgement and Disclaimer.......................................................3

5.1 Scope and Forward................................................................................4

5.2 General Requirements...........................................................................7

5.3 Salvaged Wellhead Components ..........................................................9

5.3.1 Inspection of Salvaged Wellhead Components...................95.3.2 Remanufacture of Salvaged Wellhead Components .......105.3.3 Repair of Salvaged Wellhead Components .......................11

5.4 Field Welding Installation Procedures...............................................11

5.5 Rod Pumping Wells That Have Capability to Flow to Atmosphere13

5.5.1 Sweet Wells.............................................................................135.5.2 Non-Critical Sour Wells .........................................................13

5.6 High Pressure Shut Down Systems ....................................................15

5.6.1 Testing Frequency of High Pressure Shut Down System155.6.2 Remote Shut In of Pumping Wells.......................................16

5.7 Maintenance of Wellhead Equipment................................................16

5.8 Over Stressing of Wellhead Components ..........................................16

5.9 Wellhead Protection.............................................................................17

Schematic 1.........................................................................................................19

Typical Basic Rod Pumping Wellhead .............................................19

Schematic 2.........................................................................................................20

Typical Rod Pumping Wellhead For Sweet Wells That HaveCapability To Flow To Atmosphere ..................................................20

Schematic 3.........................................................................................................21

Typical Rod Pumping Wellhead For Non-Critical Wells That HaveCapability To Flow To Atmosphere ..................................................21

Minimum Wellhead Requirements Table of Contents i


4/27

Table of Contents

Appendix A: Definitions of Terms....................................................................22

Appendix B: Additional References For Wellheads.......................................24

Minimum Wellhead Requirements Table of Contents ii


5/27

5 Minimum Wellhead Requirements

5.0 Acknowledgement and Disclaimer

This Industry Recommended Practice (IRP) is a set of bestpractices and guidelines compiled by knowledgeable and

experienced industry and government personnel, and is intended

to provide the operator with advice regarding STANDARDSFOR MINIMUM WELLHEAD REQUIREMENTS.

It was developed under the auspices of the Drilling and

Completions Committee (DACC).

DACC is a joint industry/government committee established to

develop safe, efficient and environmentally suitable operating

practices for the Canadian Oil & Gas industry in the areas ofdrilling, completions and servicing of wells. The primary effort

is the development of IRPs with priority given to:

Development of new IRPs where non-existent proceduresresult in issues because of inconsistent operating practices.

Review and revision of outdated IRPs particularly where

new technology requires new operating procedures.

Alberta Energy and Utilities Board

Alberta Human Resources and Employment

British Columbia Workers Compensation Board

Canadian Association of Oilwell Drilling Contractors

Minimum Wellhead Requirements 3


6/27

Canadian Association of Petroleum Producers

International Coil Tubing Association

Manitoba Energy and Mines

National Energy Board

Northwest Territories & Nunavut Workers Compensation

Board

Oil & Gas Commission, British Columbia

Petroleum Services Association of Canada

Saskatchewan Energy & Mines

Saskatchewan Labour

Small Explorers and Producers Association of Canada

5.1 Scope and Forward

These IRPs have been developed by the Minimum Wellhead

Requirements Subcommittee of the main Drilling and

Completions Committee (DACC). The subcommittee includedrepresentation from CAPP, CAODC, EUB, OH&S, PSAC and

SEPAC.

This document pertains only to wellheads for sweet and non-

critical sour wells. The IRPs included herein do not apply to

critical sour wells and heavy oil (conventional and thermal)wells because wellhead requirements for those well types are

specifically addressed in ARP Volumes 2 and 3 respectively.



7/27

The IRPs for minimum Wellhead Requirements which areincluded in this publication stress the importance of the wellhead

as the first line of defense to protect workers and the public and

to minimize environmental risk during the life cycle of a well.They are intended to complement existing documentation and

regulation.

The IRPs presented here are based on engineering judgement,

accepted good practices and experience. The establishment of

these minimums standards does not preclude the need for

industry to exercise sound technical judgement in the applicationand maintenance of wellheads.

The term wellhead, when used in this publication, for the sakeof simplicity, will be used generically to include both Wellhead

components and Christmas Tree components. In essence this

includes all components and related equipment form the top ofthe outermost casing string (casing bowl connection) up to but

excluding the flowline valve.

It is not the purpose of this publication to recommend wellheadconfigurations for specific application or to address each

component of a wellhead separately. This publication addressesconcerns which were identified by the subcommittee during its

review, specifically related to the following topics:

general wellhead requirements

salvaged wellhead components

field welding practices

rod pumping wells that have the capability to flow to



8/27

atmosphere

maintenance and testing frequency of high pressure

shutdown devices

over stressing of wellhead components as a result ofabnormal loading

wellhead protection

Additional references for wellhead requirements are given inAppendix B.

Every effort has been made to ensure completeness, accuracy

and reliability of the data contained in this publication. DACC,its subcommittees and individual members make no

representations, warranty or guarantee in connection with this

publication or any IRP herein and hereby disclaim liability ofresponsibility for loss or damage resulting from the use of this

IRP, or for any violation of any statutory or regulatory

requirement with which an IRP may conflict. In cases of

inconsistency or conflict between any of these IRPs andapplicable legislative requirements, the legislative requirements

shall prevail.

The subcommittee does not endorse the use of any particular

manufacturers product. Any descriptions of product types or

any schematics of components, which may bear resemblance toa specific manufacturers product, are provided strictly in the

generic sense.



9/27

5.2 General Requirements

IRP 5.2.1 Wellheads and associated piping are to be designed and

installed in accordance with appropriate API, ASME

and/or CSA standards for components and piping

installation

IRP 5.2.2 The selection and configuration of wellhead components are

to be done by or under the direction of a technicallycompetent individual who is knowledgeable in the proper

application of wellhead components.

Note:The reader is referred to the Purchasing Guidelines for

Wellhead and Christmas Tree components from API 6A,

Seventeenth Edition which provides a reference fordetermination of minimum product specification levels (PSL)

for primary wellhead components, and also to ANCE Standard

MR-01-75.

IRP 5.2.3 The installation and the energizing/pressure testing ofwellhead seals and components is to be done by an

individual knowledgeable of the specifications of the

components and trained in their proper installation

procedure.

IRP 5.2.4 Wellhead components and related equipment are to be

manufactured of materials that are suitable for the

conditions to which they will be exposed, including both

ambient weather conditions and the type of produced or

injected fluids.



10/27

For ExampleWellhead equipment manufactured from ductile iron is not

suitable for use in western Canada when exposed to extremely

low ambient temperatures.

When H2S bearing fluids are being produced or injected,

NACE standard MR-01-75 should be referenced for materialselection.

IRP 5.2.5 A wellhead must allow full bore access to the production

casing with the well under full control at all times.

Note:Shallow gas operators should note this also pertains to shallow

gas wells that are completed without a tubing string. Thismeans a master valve which permits full bore access to the

production casing must be left on the well unless the well is

killed prior to any operation requiring full bore access to theproduction casing.

This IRP also precludes reducing the casing bowl size if a liner

has been run, unless the liner is tied back to surface.

IRP 5.2.6 Wellhead equipment not included in the scope of API

Specification 6A, current edition (such as stuffing boxes,

rod BOPs, electrical feed through equipment, coiled tubing

wellhead components and so on) is to be designed,

manufactured and tested in accordance with the same

material specifications and quality assurance procedures,

and have similar trace ability requirements, as API

monogrammed wellhead components. Schematic 1

illustrates a typical rod pumping wellhead configuration.



11/27

IRP 5.2.7 Whenever the producing character of a well changes (for

example, due to recompletion, conversion or the influence

of pressure maintenance), the wellhead will be reviewed by

a technically competent individual to confirm proper

application of each component for the new producing

characteristics.

5.3 Salvaged Wellhead Components

Note: Section 5.3 applies only to wellhead components that wereoriginally manufactured to API Specification 6A. Refer to

Section 11 and Appendix J of the API Specification 6A,

Seventeenth Edition.

Note:Concern relating to this topic grows with the volume ofsalvaged equipment entering the market due to the increasing

number of wells being abandoned in Alberta.

5.3.1 Inspection of Salvaged Wellhead Components

IRP 5.3.1 Salvaged wellhead components that are to be installed on

licensed wells must be inspected prior to installation, and if

required, repaired or remanufactured as described below in

subsections 5.3.2 and 5.3.3. Such inspection must be done

either in a facility that has an API license for the repair and

remanufacture of wellhead equipment or in a facility that

follows written quality assurance procedures and uses the

appropriate gauges and tools to do the work. If the facility

doing the inspection does not have an API license for the

repair and remanufacture of wellhead equipment,

responsibility rests with the licensee of the well for ensuring

that the inspection is done following written quality



12/27

assurance procedures and using the appropriate gauges andtools to do the work.

Note:The number of times a casing bowl is recycled generated twoconcerns for the subcommittee. The first concern relates to the

internal wear to which a casing bowl may be subjected. The

second concern relates to the integrity of the connection ofweld-on bowls that have been recycled multiple times. The

impact that repeated welding operations has on the metallurgy

of the bowl has not been documented, although it is known

from experience that proper heat treating procedures are not

always followed when bowls are welded. Operators areencouraged to establish guidelines in conjunction with their

wellhead suppliers to address these concerns.

5.3.2 Remanufacture of Salvaged WellheadComponents

IRP 5.3.2.1 If a component requires remanufacture (which means

welding and / or machining, as defined in API Specification

6A, Seventeenth Edition), the work must be done in a

facility that has an API license for the repair andremanufacture of wellhead equipment, preferably in the

original equipment manufacturers facility.

Monogramming of remanufactured components is optional.

Note: The removal of a casing stub from a weld-on casing bowl is,for the purpose of this publication, deemed to be a repair and

falls within the context of subsection 5.3.3 following.



13/27

5.3.3 Repair of Salvaged Wellhead Components

IRP 5.3.3.1 If a component requires remanufacture (which means

welding and / or machining, as defined in API Specification

6A, Seventeenth Edition), the work must be done in a

facility that has an API license for the repair and

remanufacture of wellhead equipment, preferably in the

original equipment manufacturers facility.

Monogramming of remanufactured components is optional.

5.4 Field Welding Installation Procedures

IRP 5.4.1 Field welding installations of casing bowls, casing

extensions and bell nipples must be done by a welder

qualified to undertake pressure welding.

ALERT The failure of a weld connection on a casing bowl or bellnipple has potential serious consequences.

Correct field welding procedures, particularly the application ofadequate pre-heat and cool-down requirements, are often not

followed. This occurs for two reasons.

Firstly, in most cases the steel composition of the materials

being welded is not known by the welder. This is due in part to

the large variation in steel composition that exists in oil fieldcasing products, even within a particular grade, and in various

manufactured wellhead components such as casing bowls and

bell nipples.

Secondly, many of the welders being used do not have a

documented Quality Assurance Program to follow. ASME



14/27

Section IX should be referenced for information on weldingprocedure specifications and welder performance qualification.

Operators are encouraged to address the concerns related to

field welding practices by developing their own standards. The

following options are provided for consideration:

Use threaded components where appropriate and eliminate the

need for a weld.

Establish a controlled inventory of casing of known materialcomposition for use as landing joints and develop a weldingprocedure specification (WPS) for each size of casing.

Use a qualified welder from a contractor that follows adocumented Quality Assurance Program.

Establish a welding procedure specification (WPS) for thespecific materials being welded in each instance.

Note: Welder qualification or registration is done by the AlbertaBoiler Safety Association, the Saskatchewan Boiler and

Pressure Vessel Safety Unit, the Manitoba Boilers Branch, andthe British Columbia Ministry of Education, Skills, and

Training, Apprenticeship Branch.



15/27

5.5 Rod Pumping Wells That HaveCapability to Flow to Atmosphere

5.5.1 Sweet Wells

IRP 5.5.1.1 It is recommended that an environmental BOP be installed

on all rod pumping wells that have the capability to flow to

atmosphere.

Note: Environmental BOPs are manufactured either as an integral

model that is a combination environmental BOP and stuffingbox, or as a separate piece of equipment that can be installed

above or below an existing stuffing box. The environmental

BOP has the primary function of providing a seal across the

bore to prevent the release of hydrocarbons to atmosphere if apolished rod breaks and pulls out of the stuffing box. The

function is often accomplished with a spring loaded flapper.

Schematic 2 illustrates a typical rod pumping wellhead

configuration with an environmental BOP.

5.5.2 Non-Critical Sour Wells

(Refer to Appendix A for definition of sour well)

IRP 5.5.2.1 A master valve, in conjunction with a rod BOP, is

recommended for all rod pumping non-critical sour wells

that have the capability to flow to atmosphere (see

Appendix A for definition of capability to flow to

atmosphere).



16/27

Note: The master valve handle should be either removed or chainedand locked during normal production operations to prevent

accidental closure.

IRP 5.5.2.2 A hydraulic rod BOP is recommended for rod pumping

non-critical sour wells that have the capability to flow to

atmosphere. The manufacturers recommendations with

respect to operation during cold weather and frequency of

element replacement are to be followed.

Note: The primary purpose of the hydraulic rod BOP is to protect

workers safety while changing stuffing box packing elements.

It will also add an important measure of safety while servicing

the well.

The hydraulic rod BOP typically has a flexible element that

collapses inwards on itself under hydraulic pressure. It providesa positive seal either with equipment such as a sucker rod,

polished rod or wireline to seal on or without equipment in the

well, in which case it will provide a positive seal on itself. Shut

in is effected by applying hydraulic pressure either manually(hand pump) or automatically (rig hydraulics).

The element in a hydraulic rod BOP will deteriorate with time

dependent upon operating conditions. Manufacturers

recommendations and good operating practice should dictate

when the element has to be replaced. Failure to followmanufacturers guidelines when function testing, particularly

during cold weather operations, can result in damage to the

element.

IRP 5.5.2.3 It is recommended that an environmental BOP be installedon all rod pumping non-critical sour wells that have the



17/27

capability to flow to atmosphere.

Note: Environmental BOPs are manufactured either as an integral

model that is a combination environmental BOP and stuffingbox, or as a separate piece of equipment that can be installed

above or below an existing stuffing box. The environmental

BOP has the primary function of providing a seal across thebore to prevent the release of hydrocarbons to atmosphere if a

polished rod breaks and pulls out of the stuffing box. The

function is often accomplished with a spring loaded flapper.

Schematic 3 illustrates a typical rod pumping wellhead

configuration for a non-critical sour well that has capability to

flow to atmosphere.

5.6 High Pressure Shut Down Systems

5.6.1 Testing Frequency of High Pressure ShutDown System

IRP 5.6.1.1 Monthly function testing of high pressure shut downdevices on wells with sour production is recommended as a

minimum frequency.

IRP 5.6.1.2 Bi-monthly function testing of high pressure shut down

systems on wells with sweet production is recommended as

a minimum frequency.

IRP 5.6.1.3 It is recommended that operators maintain records

documenting frequency of testing and maintenance

practices.

Note: A large percentage of high pressure shutdown systems fail to



18/27

function as required if not regularly maintained and tested,particularly when in use in a sour environment.

5.6.2 Remote Shut In of Pumping Wells

IRP 5.6.2.1 A pumping well must not be shut in from a remote flowline

location without first shutting down the prime mover at the

well site, except in an emergency.

Note: The practice of shutting in pumping wells from a remote

flowline location, such as at a battery or satellite facility, relieson the proper functioning of a high pressure shut down deviceat the well to stop the prime mover. This practice presents a

risk to human safety and to the environment because of the

potential for the high pressure shut down device to fail.

5.7 Maintenance of Wellhead Equipment

IRP 5.7.1 All wellhead equipment should be installed, operated and

maintained as per the manufacturers recommendations.

Note: If a maintenance recommendation is not supplied by the

supplier or the manufacturer of a particular piece of wellhead

equipment, the onus will be on the licensee of the well toeestablish a maintenance recommendation in conjunction with

the manufacturer or supplier.

5.8 Over Stressing of WellheadComponents

IRP 5.8.1 The flowline riser at the wellhead is to be supported in thebottom of the ditch in a manner that prevents settling of the



19/27

riser after backfilling.

IRP 5.8.2 All equipment that can generate abnormal loading on

wellhead components (e.g. snubbing equipment, hydraulic

fracture piping systems with or without tree savers, coiled

tubing injectors, surface driver systems for artificial lift

equipment, etc.) must be supported and secured in such a

manner that abnormal stress is not applied to any wellhead

component.

Note: Settling of flow line risers after tie in can generate abnormal

loading on a wellhead resulting in stress points being created.This is of particular concern if the wellhead contains a tubing

head adapter (bonnet) with a threaded connection to which a

rod BOP or master valve is attached. The pin connection is

necessarily thin to achieve full bore access to the tubing string.This pin connection becomes a stress point if an abnormal load

on the wellhead occurs due to settling of the flow line riser.

This condition is accentuated if corrosion is a factor.

5.9 Wellhead Protection

IRP 5.9.1 All wellheads are to be conspicuously marked or fenced

such that they are visible in all seasons. (Wellheads with a

beam pumping unit meet this criteria).

IRP 5.9.2 The licensee and/or operator of the well shall ensure that no

farm or other vehicles operate within a 3 metre radius of

the wellhead, except for vehicles specifically required to do

so as part of an operation being performed on the well such

as a completion, workover or well servicing operation. An

exception also exists for wellheads that are below groundlevel and/or protected to accommodate certain unique

operations such as irrigation or military manoeuvres.



20/27

Note: Industry records indicate that a significant number of wellheadfailures occur as a result of impact with vehicles. Farm

equipment and contractors equipment operated too closely to

wellheads are the major sources of these impacts.



21/27

Schematic 1

Typical Basic RodPumping Wellhead

Minimum Wellhead Requirements Schematic 1 19


22/27

Schematic 2

Typical RodPumping WellheadFor Sweet WellsThat HaveCapability To FlowTo Atmosphere



23/27

Schematic 3

Typical RodPumping WellheadFor Non-CriticalWells That HaveCapability To FlowTo Atmosphere



24/27

Appendix A: Definitions of Terms

Capability to flow to atmosphere

The well has the potential to flow to atmosphere at sustained

rates of at least 0.33 m3 per hour (8 m3 per day) of liquids.

Drilling and Completions Committee (DACC)

A joint industry/government committee established to addressvarious drilling and completion related safety issues.

Primary wellhead components

The tubing head, tubing head adapter, tubing hanger and master

valve. (See Schematic 1)

Product Specification Level (PSL)

A specification that defines different levels of technicalrequirements for wellhead components depending upon the

service conditions. (Refer to API Specification 6A.)

Repair

Repair is work performed on a piece of wellhead equipment

that does not require any welding or machining to return it to areusable condition. (See Appendix J of the 17th edition of API

Specification 6a)

Remanufacture

Minimum Wellhead Requirements Appendix A 22


25/27

Remanufacturing occurs when a piece of wellhead equipmentrequires machining or welding to return it to reusable condition.

(See Appendix J of the 17th edition of API Specification 6a)

Salvaged Wellhead Component

Any component that has been installed on a well and exposedto internal pressure or fluids of any kind during any phase of

the well's life, and has been removed and is to be installed on

another well.

Sour Well

Any well that produces fluid containing 10 moles per kilomole

(1%) or greater of H2S in the gas phase.

For purposes of this publication, critical sour wells are

excluded as they are addressed in ARP/IRP Volume 2.

Wellhead

Any All components of a wellhead and related equipment from

the top of the outermost casing string (the casing bowlconnection) up to but excluding the flowline valve. For

purposes of this publication, this includes both Wellhead

Components and Christmas Tree equipment as defined by APISpecification 6A (current edition).

Minimum Wellhead Requirements Appendix A 23


26/27

Appendix B: Additional References ForWellheads

1. ALBERTA OIL AND GAS CONSERVATION REGULATIONS

Section 6.100 Surface Casing Vent requirement

Section 6.130 Capability to measure surface pressures and

to collect samples

Section 7.050 Requirements for wells with production

exceeding 5% H2S

Section 8.060 Shut down devices for wells close to bodiesof water or streams

2. ALBERTA RECOMMENDED PRACTICES (ARP'S)

Volume 2, ARP 2.1

Completing and Servicing Critical Sour Wells - Wellheads

3. INDUSTRY RECOMMENDED PRACTICES (IRPS)

Volume 3, IRP 3.3.9

Heavy Oil - Wellhead Design

4. EUBInterim Directives(ID'S)

ID 90-1, Completion and Servicing of Sour Wells

Minimum Wellhead Requirements Appendix B 24


27/27

ID 90-4, Suspension Guidelines for Inactive Wells

5. OCCUPATIONAL HEALTH &SAFETY

Bulletin ASB-24

Over-Pressuring Wellhead Components

6. APISPECIFICATIONS

Specification 6A

Specification for Wellhead and Christmas Tree Equipment

7. ASMESTANDARDS

Section IX, ASME Boiler and Pressure Vessel Code

Welding and Brazing Qualifications

8. NACESTANDARDS

Standard MR-01-75

Sulfide Stress Cracking Resistant Metallic Materials forOilfield Equipment

Date post:	23-Feb-2018
Category:	Documents
Upload:	pedro-dutra
View:	230 times
Download:	0 times

Wellhead Requirements Vol 5

Documents