SIEP - ABC Guide to Temporary Pipework Ver 02[1]

Drilling and Well Services ABC Guide to

Temporary Pipework Practices to Practices to impleme implement nt EP 20062006-5393 5393 2006-5 393 Shell Global Standard for Temporary Pipework

ABC Guide to Temporary Temporary Pipework Pipework

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Basics for Common Understanding

Pipework connected by Hammer Unions is used in chemical process plants, the mining industry, on dredging vessels and in the oil industry. It is an old design (early 1950’s) created COmpany by the Well Equipment CO mpany (WECO) which was aquired by FMC. Female / Male Unions

The identification of the Female and Male parts of a Hammer – type union is shown in the picture below.

Female Union Male Union

Wing Nut

The union parts are “called out” using a Nominal pipe size, a FIG “designation” and a code e.g.1502. For example: 2” FIG 1502 The “2” is close to the inside diameter. The meaning of “FIG” has been lost in the depths of time but is probably an abbreviation of figure - meaning drawing, and 1502 is a code for the working pressure rating - “15” referring to 15,000 psi. But over time the addition of larger diameter pipework and H2S pipework has led to the designation becoming corrupted - so beware.

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Drilling and Well Services

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The meaning of "Temporary"

"Temporary," "Temporary ," in the context of pipework and flowline equipe quipment, applies to any pipework and flowline equipment which can be installed or changed-out without recourse to structural and process engineering. ["Permanent" pipework and flowline equipment (e.g. spoolpieces connected between the production wing valve and the production manifold) are designed, constructed and installed subject to requirements of structural and process engineering codes and reviews. Without these formal checks being required for temporary pipework, the ABC Guide indicates the minimum precautions to be taken when working with temporary pipework used in Drilling and Well Services operations.] Temporary Pipework is commonly referred to as “Chicksan” or “Flowline Equipment”.


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Contents Introduction What is Temporary Pipework Equipment Involved

5 5 7

Background Information Pressure Stored Energy Dynamic Loading Vibration Bending Forces Shock Loading Hazardous Fluids

9 9 11 11 11 12 13 13

Operational Hazards Loss of Containment

14 14

Leaks - Erosion H2S Catastrophic Failure

Historic Incidents

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Pipework Connections and Interfaces Mismatches Mismatching the Same-Size Mismatching Pipe Pressure Ratings Mismatching Wing Nuts Mismatching Components Mismatching Non-Detachable and Detachable Components

Flexible Pipes

20 20 20 22 23 23 23

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Hazard Identif Identification and Mitigation Mitigation Methods Check lists No-Go areas Restraints

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28 28 28 30 30


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ABC Guide to Temporary Pipework

Avoiding Injury Hammering Unions Gauges

38 38 39

Completing the Connection Interface Diagram

40

Walking the Lines Example walkthrough

43 43

Awareness of Safety Initiatives FMC Technologies Ltd

45 45


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Introduction This ABC Guide to Temporary Pipework is designed as a practical guide to create an awareness of the issues faced when using temporary pipework in the field. This guide covers:      

Flowline equipment. Pressures and types of fluids involved. Operational hazards. Pipework connections and interfaces. Hazard identification and mitigation. Operational guidelines.

This guide should be read and understood by all involved in temporary pipework operations. The guide should also be re-read prior to the commencement of each temporary pipework operation and also referred to during each step of that operation. If the correct procedure is unclear at any stage of the operation : Stop and Ask.

What is Temporary Pipework Temporary pipework consists of the conduits and equipment for directing fluids (liquids or gasses):   

From a pump to a wellhead. A high pressure point to a lower pressure point. Fluids directed to outlets ending with plugs on which sensors are mounted.

Usually one source will be the well (the Wellhead or Xmas Tree). Occasionally, temporary pipework may be required for transfer of fluids between vessels. F igure 1 - Temporary P ipework / Permanent P ipework. Ver. 2.0

Temporary Pipework

To temporary pipework system


Permanent Pipework

Pipework part of original design (e.g. production facilities)


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Temporary pipework is piping and flowline equipment that is mobilised and assembled for the purpose of carrying out the following operations: General Pumping Operations (transfer of fluids, mud/brine mixing operations, (reverse) circulating well fluids, etc. Pressure Testing of Surface Lines and Equipment (including  wellhead, BOP, X-mas tree, flow lines, etc). Pressure Testing of Downhole Equipment (casing, packers,  tubing, plugs, valves, accessories). Cementing.  Well Killing.  Well Stimulation.  Nitrogen Pumping.  Well Clean-up.  Well Testing.  Under Balanced Drilling operations.  Managed Pressure Drilling Operations.  Temporary pipework can be both hard and flexible pipe. 

F igure 2 - T y pical Temporary P ipework Set-ups


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Equipment Involved         

Pipework runs (straights), pup joints, elbows. Strainers, pots, plug valves, check valves. T-pieces. Laterals (Y-pieces). Swivel joints. Treating Loops. Crossovers. High Pressure Hoses. Flanges & Blinds. Treating loop

Pipework

Chiksan (Swivel) Joint Tee

Typical Coflexip Line

F igure 3 - Some typic al equipment inv olved

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The pipework connections referred to in the guide are known as:    

Hammer-type connections. Hub-type connections. Flange connections. Pipe body to pipe body (welded).

Hammer-type Union

Graylok Hub-type Connection

Flange Connection

Welded Connection

F igure 4 - Temporary P ipework Conne ctions

In summary, Temporary Pipework (chicksan, flowline equipment) comprises such fittings as straights or “pup joints”, T-pieces, elbows, crosses, crossovers, blinds, plugs, swivel joints and plug, loops and check valves. A combination of such equipment is often referred to as “steel hose”.


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Background Information As previously described, Temporary Pipework Operations involves the transport of fluids under pressure from one point to another. Due to the typical pressures and flow rates involved, Temporary Pipework Systems contain a lot of stored energy which can cause vibration, bending forces and shock loading on the system. The fluids being flowed can be hazardous or corrosive and can therefore also “attack” the integrity or strength of the system. It is therefore vitally important that all equipment used in a Temporary Pipework Operation set up is: Mechanically sound and has been properly inspected prior to use. Of suitable material, particularly where seals are concerned;  this applies both to working pressure rating and to the fluid type being flowed (e.g Sour Service). Made up correctly at all connections and unions as per the  recommendations of the operational design. Secured with the proper restraints attached to the proper  anchor points in the system. In order to better understand these requirements we will now look at some of the physical factors that Temporary Pipework set-ups have to cope with. 

Pressure Pressure is the term for measuring the force per unit area, the units typically used for measuring pressure are pounds per square inch, which is abbreviated p.s.i. A familiar example is the air pressure in a tyre, which is typically around 30 p.s.i. for a car. What this means is that a force of 30 pounds is exerted on each and every square inch of the inside of the tyre, There are a lot of square inches on the inside

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Units of Pressure

Pounds per square inch (or pounds-force per square inch) is still the most widely used oilfield unit for pressure. Other common units are the SI (or metric) unit which is the Pascal (Pa), the Atmosphere (atm), and the Bar (bar). The Pascal is a very small unit, 1 Pa being only about 1/7000th p.s.i. 1 Atm and 1 Bar are approximately 15 p.s.i.


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surface of a tyre, and because of this, the force exerted on that tyre is very large. Every square inch is pushed on with a force of 30 pounds. In Temporary Pipework Operations, “low pressure” is often used for values of around 300 p.s.i. (that is TEN times that of a car tyre) and the operational pressure may be above 10,000 p.s.i. That is 10,000 lbs exerted on every square inch of the inside of piping, unions, swivel joints, crossovers etc in the system.

F igure 5 - Relative Pressure Comparison

Thinking about the forces involved, it should be clear why it is vital to ensure there are no weak points in the system. Any improper use of equipment such as mismatching pressure ratings or using poorly conditioned equipment can have devastating consequences.


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Stored Energy Stored energy is the capacity of a volume of pressured fluid to do work if allowed to expand. An example of this work would be a volume of pressurised gas expanding and pushing a piston. The greater the stored energy of the fluid, the greater the force with which the piston would be pushed and the greater the amount of work that piston could perform. The danger associated with Stored Energy in Temporary Pipework is that the Stored Energy is typically very large and any weak point in the system will allow this energy to expand with potentially catastrophic results

Dynamic Loading

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Yield strength

Yield Strength is the stress a material can withstand without permanent deformation. Typical minimum yield strengths for pipework range from 75,000 to 115,000 psi It is interesting to compare Temporary pipework with the guidelines for artillery safety regarding the use of cannons in historical re-enactments. The guidelines state that: “The bore should be lined with steel tubing with a minimum wall thickness of 3/8” and yield strength of 85,000 psi or greater”. A liner equivalent to pipework is what a cannon requires to safely contain and direct the stored energy which propelled 8lb cannon balls in the American Civil War!

When pipe bursts the strain on any restraint when it snaps tight to restrain the pipe is called the dynamic loading by process engineers. The rule-of-thumb used to work out this dynamic loading is twice that due to the static force on the pipe arising from internal pressure.

Vibration Vibration can be a significant risk to pipework integrity, leading to mechanical failure, fluid release, and potentially serious safety implications. Common areas of vibration in Temporary Pipework are    

Long pipe runs . Piping appenditures such as gauges. Equipment such as valves, chokes, etc. Pumps.

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F igure 6 - Vibration in Temporary Pipework

Common causes of Vibration Excessive Pulsation (from pumps for example). Mechanical Natural Frequencies.  Inadequate Supports and/or Support Structure.  Common effects of Vibration 

 



Loosening of Bolts. Compromising of Mechanical Joints (backing-off of Wing Nuts). Movement or slackening of Tie Downs and Restraints.

Bending Forces Temporary Pipework is commonly subjected to bending forces due to fluid velocity and internal pressure of the pipe. Bending force occurs at junctions or bends in the pipework where it effectively tries to “straighten out the bend”. Bending force attempts to straighten out the corner bend and forces the pipe outwards straining the connections

F igure 7 - Bend is being straightened due to bending forces


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Such bending forces are then transferred along the pipework and result in additional strain on connections. Improperly made-up connections (e.g. worn or mismatched components, wrong pressure rating etc) not able to cope with this increased load can fail catastrophically.

Shock Loading A significant change in the flowrate, or pressure, during an operation (such as the emergency closure of a valve) causes a sudden extra load or “jolt” on the system. This is temporary increase of load on the system usually imposes increased pressure, vibration, and bending forces on the system. During this period of Shock Loading, any sub-standard part of the system (inferior pipe, worn connections, mismatched connections, wrong pressure rated equipment) can fail with potentially disastrous consequences. It is important to consider that failure due to Shock Loading may occur when there is already an emergency event of some kind already taking place (e.g. an emergency shut-in).

Hazardous Fluids While there are many physical factors (such as pressure, temperature and flowrates) that must be considered when dealing with temporary pipework, chemical factors such as hazardous fluids must also be taken into account. Many fluids involved in operations (such as brines or acids) are corrosive to temporary pipework and will weaken pipework over a period of time. It is important that all pipework and connections used have been properly maintained, inspected and certified before use. Standard Service components must not be used on “Sour Service” wells (wells where Hydrogen Sulphide, H 2S, is present) as this will cause stress corrosion cracking, and pitting in the metal as well as destroying any elastomer seals in Unions etc. Both of these factors will lead to premature failure under pressure of components in the system.

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Operational Hazards Loss of Containment Leaks - Erosion

Erosion takes place in flow systems where turbulence occurs, typically in pipe bends (e.g. elbows), tube constrictions (e.g. chokes or valves), and other structures that alter flow direction such as laterals or tees. Specific erosion points within these components can vary depending on the fluid velocity and size of any suspended particles. With typically sized sand grains, the erosion point in a bend is usually past the mid-point of the bend and it is for this reason that wall thickness is measured at the 80-90 degree point.

80o

Erosion point

F igure 8 - Er osion point in a short radius bend

Erosion can lead to leakage a rapid failure and it is therefore important that the layout is designed, where possible, to minimise bends and constrictions and that such areas are inspected regularly. Intrusion into the flow path can cause vortices to be created and shed. The local fluid speed within the vortex can be much greater than the average fluid speed in the pipe. Local pipe erosion, in an area as small as 1/2 inch square, can arise where the vortex makes contact with the equipment or pipe wall. Since the pipe thickness can be otherwise within operational limits, workshop personnel should be vigilant when making visual inspections. Drilling and Well Services

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Flow

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Flow Maximum erosion Maximum erosion

Plugged tee

Standard elbow (r/D=1.5)

Flow Maximum erosion

Long-raduis elbow (r/D=5.0)

Predicted erosion rates for standard elbow, plugged tee and longradius elbow. Areas shown in red and yellow have maximum erosion

F igure 9 - Erosion of common equipment

H2S

When H2S is present, the system is known as Sour and Sour Service equipment must be used. For working pressure above 6000 psi, Sour Service equipment has a significantly lower rated cold working pressure than than the equivalent Standard Service equipment and it is therefore important to avoid mixing Standard and Sour Service equipment in the same operation. Ver. 2.0



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Catastrophic Failure

When flow lines fail; whether it is due to excess pressure, faulty connections, worn components, damage to the piping connection, or other reasons; the results can be devastating and catastrophic to both equipment and personnel. The metal components that were previously being subjected to up to 15,000 p.s.i. of internal pressure are suddenly and instantly forced to relieve their stored energy. In such a failure there could be hundreds or even thousands of pounds of iron pipe flailing around. In that scenario, there is a high likelihood of severe personal injury or death. As we will cover later, restraint systems can help reduce this risk of damage or injury but they cannot eliminate it fully. Preventing the failure from occurring in the first place is the only truly safe method.

Energy Release The following sequence of pictures were taken from a Schlumberger demonstration video showing the failure of a 15,000 p.s.i. unrestrained line. In this catastrophic failure the energy release occurs in a very short period of time - a fraction of a second in fact, and the damage and risk to personnel would have been severe.

Line ruptures

Test manikins 15,000 psi line

Pup joint f lies off and lands 200 yards away

Test manikins destroyed

Piece of loop f lies outward

F igure 10 - Demonstration of energy involved in Catastrophic Failure


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Historic Incidents Equipment

Operation

Event

Cause

Chicksan

Pressure Testing

Chiksan elbow parted at swivel at 4800 psi

Snap Rings and Ball Plugs were missing

Hammer Union

Pressure Testing

WECO union pressure sensor connection on rig floor ripped off.

Mismatch between standard 2” 1502 WECO Union and rigs “2” 1002 WECO union

Hammer Union / Chiksan connection

Making up pipe

A 2 inch WECO union with a swivel connection made up hammer tight, became unscrewed while tubing (onto which the union was connected) was being made up. The swivel assembly fell 10 metres on to a floorman resulting in severe injury leading to death.

Hammer tight right hand connection is not reliable when rotated in this manner. Such connections must always be snubbed and attached to a safety sling.

Hammer Union Plug End

Well Test

Female hammer union plug end dislodged from a side outlet of a sand filter, with a pressure of 3,500 psi, while the injured party was operating a valve. This resulted in multiple injuries leading to death.

Mismatch in connection between 602 female and 1502 hammer wingnut.

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Equipment

Operation

Event

Cause

Hammer Union Seal

Well Cleanup Operation

Vapour release from connection

Hammer Union

Clean-up of Wellhead and BOP prior to pressure testing.

While circulating through a standpipe manifold, a section of chiksan line was blown from its connection on the drain line manifold. Mud escaped onto rig floor and over drilling equipment.

During operation, flowing temperature went below minus 20 deg C (4 deg F) of the rating of the seal. (This is the same failure that caused the Challenger disaster!) Mismatch in connection between 2” 1502 hammer lock fitting on the chicksan and a 2” 1002 male fitting on the standpipe. The pressure at the time of failure was approximately 2900 psi

Hammer Unions and Swivel Joints Flexible Hose

General

Multiple failure of Hammer unions due to poor make-up.

In Service

2” flexible hose terminated in a 1502 chicksan male/female connections failed in service.

Hammer Union

Equipment Testing Incident occurred during water flow test through a Mud Line Cellar Bit.

Shortly after pumping started, a 2” 602 hammer union on the pump stand pipe separated. An Assistant Driller was struck and fatally injured by the male half while reading a gauge. Drilling and Well Services

Hammer lugs tend to deform and thereby reduce the efficiency of hammer blows There was evidence of corrosion, splitting and cracking, (manufacturing defect - slight over swaging), no routine inspections, hose assembly over 2 years old. Mismatch of 2” 602 female and 1502 male. Higher than expected pressures due to misalignment of the rig floor manifold. Assistant driller was in “line of fire”.

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Equipment Flexible Hose

NPT Tape Threaded Fittings

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Operation

Event

Cause

Pressure Venting

During pressure venting after transfer of bulk chemicals, a 4” flexible hose was lowered over side of vessel into the sea to prevent dust clouds during venting. It was kept submerged by using an old valve and ballast chain on the outboard end and had a 4m length of rope to aid recovery. A sudden release of compressed air occurred when a vent valve in the engine room was opened and caused the vent hose to whip out of the sea onto the deck of the vessel where a crew man was struck on the head and fatally injured.

There was an uncontrolled release of pressure due to vents being opened in the wrong sequence.

On inspection a number of NPT fittings made up to several hose connections appeared to not be fully made up.

Fittings were found to be galled and only connected with effectively only two threads. Further investigation confirmed that these fittings were outside acceptable tolerance standards.

Make-up Inspection


The hose was not adequately secured to preventing whipping onto the deck and the method used was not safe or recommended practice. The crew man was in a dangerous position and had apparently ignored verbal instructions to clear the area before venting.


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Pipework Connections and Interfaces In earlier sections it has been shown how important the quality of pipework connections and interfaces is to the integrity of the system. Improperly fitted, rated or sized connections repeatedly prove to be the weak point of the system when exposed to operating conditions.

Mismatches Mismatches in Hammer Unions are severe mechanical hazards to the integrity of the Temporary Pipework System. They are weak points that may fail under pressure and can result in serious personal injury, death and/or property damage. Such Mismatches occur in 5 main categories: Mismatching the Same Size. Mismatching the Pressure Ratings.  Mismatching of Wing Nuts.  Mismatching of Components.  Mismatching of Non-Detachable and Detachable Components.  Avoiding these Mismatches is of prime importance in all aspects of Temporary Pipework Operations. To further illustrate this each Mismatch is covered more fully in the sections below. 

Mismatching the Same-Size

These mismatches refer to connecting Hammer Union products having the same size, but different figure numbers. Improper matching of this equipment can lead to two very dangerous situations: 1

Two parts of a hammer union with different pressure ratings, and

2

Union threading appearing to be fully made up when in fact only a portion of the threads are made up.

This will lead to a failure under pressure. For Example: 

The Wing Half of the 602 can mate up with the female 1002 but the common belief that it will hold the lower pressure rating of the two models is incorrect. This is a potentially dangerous mismatch and must be avoided.


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The Wing Half of the 1002 can mate up with the female 602, but again, the common belief that it will hold the lower pressure rating of the two models is incorrect. This is a potentially dangerous mismatch and must be avoided. And most seriously The Wing Half of the 1502 can accept a female 602 or 1002.  This connection can appear to make-up and maintain a significant pressure (up to 3,500 p.s.i). However, once this pressure is exceeded, either section can become a projectile and can cause death, serious injury or equipment damage. This will also release high pressure fluids which are a clear hazard to health and the environment. The integrity of the Union is compromised by the depth of thread engagement of the nut thread with the female union, the threads have the same pitch so the connection can appear to be secure, but it is not; such connections will fail. 

MIS-MATCH! Never connect products with hammer union end connections that are not positively identified as to the manufacturer and that are not identified to have identical union figure number, size and pressure rating. Mismatched connections may fail under pressure, which can result in serious personal injury, death and/or property damage.

1502 Male Sub and Wing Nut

602 Female Sub

The following Hammer union mismatches are possible and must be avoided Size

Union Figure Nos

1 1/2”

600, 602, 1002

2”

402, 602, 1002, 1502

5”

400, 1002

THE 2” 602 AND 2” 1002 UNIONS A RE BANNED IN SHELL . THEY MUST BE IDENTIFIED BY CONTR ACTORS A ND INSTA LL ATIONS AND SYSTEMATICALLY REMOVED AND REPLACED WITH 2” 1502 UNIONS. Ver. 2.0



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Use of the Go No-Go Gauge

The Go No-Go Gauge should be used to be sure you have a 1502 Female Sub. The gauge wil be “No-Go” on a 1502 sub but will be a “Go” on a 602 sub. 2” 1502 Female - NO-GO

2” 602 Female -GO

Mismatching Pipe Pressure Ratings

This Type of mismatch refers to connecting Hammerlug Union products having different pressure ratings but with end connections of the same size and Figure number. This occurs when mixing Sour Gas pipe with Standard Service pipe or when mixing Unions attached by pipe threads to pipe of service different to that specified by the Union. Wing union components that cannot be positively identified with regard to manufacturer, size, figure number, pressure rating and type of service must never be used. Incorrectly identified components will lead to hazardous assemblies, which can fail under pressure and result in serious personal injury, death and/or property damage. 15,000psi WP

2” 1502 Standard Female Sub

10,000psi WP

2” 1502 Sour Service Male Sub and Wing Nut

MIS-MATCH! Wing union components that cannot be positively identified with regard to manufacturer, size, figure number, pressure rating and type of service must never be used. Incorrectly identified components will lead to hazardous assemblies, which can fail under pressure and result in serious personal injury, death and/or property damage.


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Mismatching Wing Nuts

This mismatch occurs when the Wing nut of one Size and Figure number is mounted on the male sub of another Size and Figure number. There is only a small amount of engagement of the male sub in the wing nut and therefore the connection will not safely hold typical working pressures.

MIS-MATCH!

2” 1502 Wing Nut

2” 602 Standard Male Sub

Never assemble any combination of male sub, wing nut or segments that are not positively identified to assure that union figure number, size, pressure rating and manufacturer are identical. Mismatched components will result in hazardous connections, which may fail under pressure, which can result in serious personal injury, death and/or property damage.

Mismatching Components

Mismatching of Components occur when segments and nut of one Figure number are made up to a detachable male sub with a different Figure number. This results in a small amount of engagement of the male sub with the segment engaging the wing nut. This will not hold pressure safely during typical operations.

MIS-MATCH!

2” 1502 Wing Nut

2” 602 Detachable Male Sub

Never assemble any combination of male sub, wing nut or segments that are not positively identified to assure that union figure number, size, pressure rating and manufacturer are identical. Mismatched components will result in hazardous connections, which may fail under pressure, which can result in serious personal injury, death and/or property damage.

Mismatching Non-Detachable and Detachable Components

This mismatch is caused by the assembly of non -detachable nuts on detachable male subs. The detachable wing nuts require a longer thread length to compensate for the segments between the wing nut and the sub shoulder. Use of a non-detachable wing nut in a Ver. 2.0


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detachable Union results in a lack of thread engagement and an insufficient engagement between of the male sub shoulder with the wing nut ID.

MIS-MATCH!

2" 1002 non-detachable nut inappropriately used in a detachable union assembly. Notice the resulting lack of thread engagement with the female sub.

The misapplication of standard, non-detachable style wing nuts on 2", 3" and 4" Figure 602 and 1002 detachable nut connections will result in an unsafe connection leading to separation when under pressure. Failure to avoid this condition may result in death, serious personal injury and severe property damage.

MIS-MATCH!

4" 1002 non-detachable nut inappropriately assembled to a detached male sub end. Notice the excessive play between the ID of the nut and male sub OD behind the shoulder.

The misapplication of standard, non-detachable style wing nuts on 2", 3" and 4" Figure 602 and 1002 detachable nut connections will result in an unsafe connection leading to separation when under pressure. Failure to avoid this condition may result in death, serious personal injury and severe property damage.

Mismatching Swivel Joint Components The TripleStep (TSi) swivel joint, manufactured by FMC, employs a stepped ball race design. Differences in the swivel load capacity over traditional nonstepped race designs mean that potentially serious occurrences that could result from mismatching swivel joint components of different designs and/or manufacturers. Like the FMC 3” TSi swivel joint, the recently introduced SPM 3” HD-LR swivel joint employs a stepped ball race feature. FMC’s 3” TSi swivel joints employ a one ball step in raceway diameter between each of the three raceways. SPM’s HD-LR swivel has a


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step between only two of the raceways. In addition to the stepped race similarities, the axial spacing between the raceways of the two models is very similar. Because of these similarities, it is physically possible to erroneously assemble a male race end of a SPM 3” HD-LR component into the female race end of an FMC 3” TSi component. This mismatch of components may falsely give the impression of a proper assembly, since the swivel assembly may feel tight and hold pressure. While the resulting assembly may give the false sense of a correct assembly and would likely contain pressure, the assembly would not be structurally sound. This condition would result in a swivel connection that is unsafe and could potentially lead to catastrophic failure of the connection. Gap in 3” ball race

SPM 3” HD-LR male ball race end

No step between second and third race

FMC 3” TripleStep female ball race end

Male race interferes with female end

FMC 3” TripleStep male ball race end

Dangerous Mismatch to be Avoided

SPM 3” HD-LR female ball race end

Mismatch Avoided

F igure 11 - Dangers of mismat ching Swivel Joint Component s

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Flexible Pipes Flexible pipes or hoses are resistant to bending, including frequentcontinuous flexure, however it is impreative that they are handled, stored and maintained correctly. In general: 







The preferred installation for a flexible line is with the pipe positioned in a J or U configuration, with the end fittings pointing up in a vertical position. Do not leave medium to longer lengths of horizontal pipe unsupported. Ensure flexible pipe is not bent over or resting on sharp edges any vibration will cause damage at such points. Do not exceed the minimum bending radius of flexible pipe. [As a rule of thumb, the minimum bending radius (MBR) is roughly 12 x the I.D. of the pipe].

MBR d = (2 x MBR - OD) “d” is the minimum inside distance between two surfaces F igure 12 - Minimum bending radius of Flexible Pipe.


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Soft strops with shackles

Cable SWL 5.7t

5

4

2 3 SF4

PN 15m

Chain block

Steel sling or soft strop SWL 5t

Cable Deck beam

One shackle connection SWL 6t as cable is not long enough

Similar configuration for coflex on both ends

2 4 3

F igure 13 - Hose Installing Concept for long spans

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Hazard Identification and Mitigation Mitigation Methods Check lists Pre-Pressure Test Temporary Pipework “Walk-the-Lines” Check List

The purpose of the checklist is to ensure that the Temporary Pipework and equipment: 

 

Is hooked-up in compliance with the approved drawings and equipment lists. Can be operated as required by the Programme. To ensure the adequacy of the ratings of the interfaces and blanked-off outlets.

Checklists are an orderly and sequential collection of “best practices” for confirming the configuration of temporary pipework for safe operations. Checking a temporary layout must often be undertaken amid a host of competing job priorities. Routine supervisory duties can interfere with “walking-the lines” resulting in failure to complete the checklist and confirm the correct configuration of the temporary pipework. The consequences of disrupted or interrupted checklists are varied and potentially serious and must be avoided. The key points are: 1. The Wells Services Supervisor (WSS) and the Contractor Services Supervisor (CSS) are jointly responsible for ensuring that the Temporary Pipework is hooked-up as required by the approved P&ID or Process Flow Diagram. 2. Any deviation in the Temporary Pipework hook-up from the requirements of the Standard for Temporary Pipework (EP 2006-5393) needs a “Dispensation”. 3. A confirmation that all temporary pipework has been certified (maintained and tested) according to Contractors’ procedures (endorsed via contract awarded by Shell). Specifically that no equipment is “derated” or below the minimum wall thickness allowed. 4. The checks may be carried out Line Section by Line Section determined by specification (pressure) breaks progressing from high pressure to low pressure. Drilling and Well Services

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5. Refer to EP 2006-5393 Appendices for specific hammer union mismatches and restraint dynamic loads. (Note specifically: both male and female 2” Fig 602 and 2” Fig 1002 unions are banned in all configurations e.g. vessel outlets, burner boom piping). 6. Where appropriate, record the number of connections inspected (Count) or equipment identification number (Eq. no.) in the “tick” column and if “NO” is ticked, the Reason. Location/Well:

Job No.

Programme:

Supervisors: Reference Drawing No.

Date: Reference Equipment List(s):

Line Section: Dispensations Requested for this line section: Item/ Description of Check Procedure

YES

NO

Count/Eq No.

Reason

1. Check pressure rating of upstream interface connection and subsequent connections in the line by reference to banding. 2. Check pipework material for suitability for service. 3. Check that the number of swivels has been minimised. 3. Check/confirm that correct bolts and gaskets are installed at all mechanical joints and bolt engagement. (Bolts shall extend completely through the nut with at least one thread exposed at each end. Confirm that bolting has been made up to the correct torque with calibrated torque wrenches.) 4. Check sealant on screwed connections is as per specification. 5. Check/confirm elastomers in hammer unions are compatible with fluids/service. 6a. Confirm that vessel/equipment outlets, not in the flow path and potentially subject to being pressured are appropriately blanked. Where the blanking comprises a male or female hammer union confirm the FIG no. and service is compatible with the vessel/equipment specification. 6. Check for correct flow through filters and strainers, traps, check valves, globe valves and control valves. 7. Check that the valve positions are tagged (open/closed) and are correctly lined up for the pressure testing. Where a valve is required to be locked open or closed, ensure that the locking system is sufficiently robust, preventing it from being simply overridden. Note those valves the position of which needs to be altered for the first operation. 8. Check that all chain wheels and extended spindles required for specified valves have been installed 9. Check that orifice flanges have required upstream and downstream ‘clearances’. 10. Check that all vents and drains are installed. The drains should be at the lowest points and vents at the highest points. Check for proper slope (e.g. flare lines). 11. Check all instrument thermowells installed. Check that welded nipples are properly installed. Threaded nipples shall be checked for engagement, Check that they have not been seal-welded. 12. Confirm the setting of pressure pilots, and sizing of pressure reliefs. 13. Confirm the safety of electrical instruments. 14. Check that all pipe supports, anchor point, clamps and restraints are adequate. (Confirm that expansion allowance has been provided. Confirm that there is no excessive bending moment resulting from lack of support or overloading from tugger lines on the pipework.) 15. For items marked ‘No’, raise outstanding works list and ensure that it is completed prior to pressure testing.

F igure 14 - P re-Pressure Test Temporary Pipework Che ck List Ver. 2.0


N/A


30

No-Go areas 



During pressure testing keep at least 2 pipe run lengths away from the line under pressure. Keep out of line-of-sight of pressured plugged outlets, instrument connections on vessels and flowline equipment.

Restraints

The system of restraints demonstrated in this Section is provided by WeirSPM. The WeirSPM system of restraint has sufficient strength to restrain pipework for the loading tabulated in the Temporary Pipework Standard, Appendix 3 (reproduced below), and has been tested at the instigation of Shell for restraining pipework rigged up for high temperature (250oF) operations. EP 2006-5393

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APPENDIX 3.

DYNAMIC LOADING ON RESTRAINTS – PIPEWORK CONNECTION BURST CASE

Dynamic Forces created by Se awater for system pressures (Kilo Pounds-Force / Metric Tonnes) Nominal Pipe OD (ins) 2 3 4

Restricted

Dynamic Forces created by Gas (N2) for system pressures (Kilo Pounds-Force / Metric Tonnes)

5,000 psi

10,000 psi

15,000 psi

5,000 psi

10,000 psi

15,000 psi

21 / 9.55 41 / 18.6 68 / 30.9

42 / 19.1 82 / 37.3 135 / 61.4

64 / 29.1 124 / 56.4 204 / 92.7

17 / 7.7 33 / 15.0 55 / 22.0

31 / 14.1 56 / 26.8 99 / 45.0

42 / 19.1 82 / 37.3 138 / 62.7

Note: Information extracted from Reference [5]

F igure 15 - Extracted table showing Dy namic Loading on Restraints

Note that liquids produce higher dynamic loading than gas at the same pressure. The reason for this is that loading is proportional to the density of the fluid being discharged. With gas the discharge to low pressure takes longer, but the intitial shock is less than that from liquid at the same pressure.

Fibre Rope Restraints (FRRs) are intended to help contain highpressure piping and components in case of rupture or excessive impulse during the pumping process. When flow lines fail, whether it is due to excess pressure, faulty connections, worn components, damage to the piping connection, or otherwise, the results can be devastating and catastrophic to both equipment and people. The metal components that were previously being subjected to up to 15,000 p.s.i. of internal pressure are suddenly and instantly forced to release that stored energy. In a failure there could be hundreds Drilling and Well Services

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or even thousands of pounds of iron pipe flailing about in an unrestrained condition. In that scenario, there is a high likelihood of severe personal injury or death. FRRs reduce, but do not eliminate, that risk. Installation of individual FRR components as well as the system itself should be done by trained personnel. Installation Steps 







Install FRR system after entire flow line is setup. Hammering wing nuts can be clumsy with FRR equipment installed. When possible, fill the flow line system with water (no pressure) and look for leaks before installing FRR system components. After the safety restraint system is installed, check every connection, every link, and every FRR component to ensure that there is a continuous connection from anchor point to anchor point. After FRR system is installed, make sure: a) All FRR ribs are installed as tight as possible around flow line components. b) All main line and anchor line spine FRRs are as tight as possible from anchor point to anchor point.

Always keep ALL personnel not essential to the operation away from flow line system while under pressure. This applies even when a safety restraint system is installed. The following pictures illustrate the jacketed fibre rope flowline restraint system supplied by WeirSPM.

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Step by Step Installation 1

End “A”

2

“A”

End “B”

“B”

Position the rib beneath the flowline and straddling the union assembly. It may be necessary to raise the flowline slightly with a pipe jack to achieve this.

Keeping end “B” stationery, bring end “A” up over the union assembly towards end “B”

3

4

“A”

“A”

“B”

“B” Next, bring end “A” down through the end “B” opening.

Continue to pull end “A” through the end “B” opening and under the union assembly back towards the end “A” starting point.

5

6

“A”

“A” “B”

“B” Again, loop end “A” over the union assembly towards end “B”

Draw end “A” even with “B” end, ensuring that the rib fits snugly around the union assembly.


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7

8

“B”

“A” “A”

“B” Both loop ends are now gathered ready for installing the spine.

To take up any slack and ensure a more secure connection, both loops are rotated together from flat.

9

10

“A”

“B”

“B”

“A” Ideally, this rotation should be continue through 270 degrees.

If there is not enough slack to allow a rotation of 270 degrees, then the rotation cand be stopped at 90 degrees from flat.

11

Once this “twist” loop has been formed, the end of the spine can be fed through it.

12

The spine can then continue to be pulled through other installed ribs. Note, it is recommended that all ribs are installed before installing the spines.

Figure 16 - Recommended f ibre r ope installation method

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Rib Locations Union connections

FRR Ribs should be installed on EVERY union connection on the flow line (one rib per union). The rib envelope must always straddle both sides of the union in order to help contain each end of the adjoining pipes/components.

F igure 17 - Fibre rope rib installation at a Union Connection

Swivel Assemblies

Swivel assemblies should have FRR ribs installed at the two wing union connections at each end, and also around unsecured swivel joint connections.

Figure 18 - F ibre rope rib installation at a Sw ivel Assembly Drilling and Well Services

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Flow Line Components

Virtually all flow line components utilise two wing union connections – usually male x female. Therefore, most flow line components (check valves, plug valves, etc.) require FRR ribs installed at each end as shown.

F igure 19 - F ibre rope rib installation at a F low Line Component

Long Piping Assemblies

Most piping assemblies can be treated like other flow line components - with one FRR Rib installed on each union connection at each end. However, on piping assemblies 10 feet or longer, it is required that a third FRR rib also be installed midway between the two union connections. This centre rib will not have the union connection to help prevent it from moving, however, field testing has shown that this rib will help provide extra support should a failure occur.

F igure 20 - F ibre rope rib installation on a L ong P iping A ssembly

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SIEP - ABC Guide to Temporary Pipework Ver 02[1]

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