SIST EN ISO 13354:2014

Petroleum and natural gas industries - Drilling and production equipment - Shallow gas diverter equipment (ISO 13354:2014)

ISO 13354:2014 specifies requirements for the selection of the diverter equipment for rigs used to drill shallow-gas-bearing formations. It covers both onshore and offshore drilling operations, and considers also the auxiliary equipment associated with floating rigs.
The specified requirements concern the following diverter equipment:
annular sealing devices;
vent outlets;
diverter valves;
diverter piping.
ISO 13554:2014 highlights the concerns associated with the selection of a marine floating drilling support. It covers safety issues concerning key rig equipment, and important steps of action required prior to starting the drilling operations.
It provides only general guidelines regarding the response to be given to a shallow-gas flow.

Erdöl- und Erdgasindustrie - Shallow gas Diverterausrüstung (ISO 13354:2014)

Industries du pétrole et du gaz naturel - Équipements de forage et de production - Équipement déflecteur pour gaz de surface (ISO 13354:2014)

L'ISO 13354:2014 spécifie les exigences pour le choix de l'équipement déflecteur des appareils de forage qui sont requis pour forer des formations contenant du gaz de surface. Elle couvre les opérations terrestres et en mer, ainsi que les équipements auxiliaires requis sur les engins flottants.
Les exigences spécifiées concernent les équipements suivants:
?   dispositif d'obturation annulaire;
?   sorties d'évent;
?   vannes du système déflecteur;
?   conduites du système déflecteur.
L'ISO 13354:2014 met en lumière les préoccupations associées à la sélection d'un support de forage flottant. Elle couvre les aspects sécurité liés à des équipements essentiels de l'appareil de forage, ainsi que les actions importantes devant être réalisées avant le démarrage des activités de forage.
Elle ne fournit que des recommandations d'ordre général à propos des actions à mener en cas de venue de gaz de surface.

Industrija za predelavo nafte in zemeljskega plina - Vrtalna in proizvodna oprema - Oprema "Shallow gas diverter" (ISO 13354:2014)

Standard EN ISO 13354 določa zahteve za izbor opreme za preusmeritev za ploščadi, ki se uporabljajo za vrtanje plitvih formacij plinov. Zajema postopke kopenskega vrtanja in vrtanja v morsko dno ter dodatno opremo, povezano s plavajočimi ploščadmi. Določene zahteve se nanašajo na naslednjo opremo za preusmerjanje: obročaste tesnilne naprave; - prezračevalne odprtine; - preklopne ventile; - preklopne cevovode. Ta mednarodni standard izpostavlja težave, povezane z izbiro morske plavajoče podpore za vrtanje. Zajema vprašanja o varnosti v zvezi s ključno opremo za ploščadi in pomembne korake za ukrepanje, ki so potrebni pred začetkom vrtanja. Ta mednarodni standard izpostavlja težave, povezane z izbiro morske plavajoče podpore za vrtanje. Zajema vprašanja o varnosti v zvezi s ključno opremo ploščadi in pomembne korake za ukrepanje, ki so potrebni pred začetkom vrtanja. Zagotavlja le splošne smernice glede odzivov na tok plitvih formacij plina.

General Information

• Status: Published
• Public Enquiry End Date: 19-Jan-2014
• Publication Date: 28-Sep-2014
• ICS: 75.180.10 - Exploratory, drilling and extraction equipment
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 24-Sep-2014
• Due Date: 29-Nov-2014
• Completion Date: 29-Sep-2014
• Ref Project: EN ISO 13354:2014 - Petroleum and natural gas industries - Drilling and production equipment - Shallow gas diverter equipment (ISO 13354:2014)

Overview

EN ISO 13354:2014 - Petroleum and natural gas industries - Drilling and production equipment - Shallow gas diverter equipment - specifies requirements for the selection, layout and use of diverter systems used when drilling shallow-gas-bearing formations. Adopted by CEN from ISO 13354:2014, the standard covers both onshore and offshore drilling, and addresses auxiliary equipment for floating rigs. It focuses on key diverter components such as annular sealing devices, vent outlets, diverter valves, and diverter piping, and provides guidance on preparations, inspections and maintenance.

Key topics and technical requirements

• Scope and purpose: Selection criteria for diverter equipment to improve safety when drilling in shallow-gas formations.
• Diverter equipment covered:
  • Annular sealing devices (torus-shaped housings with annular packing elements)
  • Diverter valves and actuators (manual, hydraulic, pneumatic, electrical)
  • Vent outlets and diverter piping, including cleanouts
• Layout considerations: Recommended arrangements for land rigs, bottom‑supported marine structures and floating rigs, with attention to riser use and additional diverter functions on floating support.
• Pre-spud preparation: Requirements for call-for-tender items, important safety issues, pre-spud checks, meetings and drills to prepare crews for shallow-gas scenarios.
• Inspection, testing and maintenance: Guidance on routine inspection, maintenance and manufacturer documentation for diverter systems and piping.
• Safety emphasis: Highlights hazards of shallow-gas kicks - fast-developing flows, erosion and dynamic loads - and the need for reliable, simple diverter systems; offers general guidelines on response planning rather than detailed blowout response procedures.

Applications and who uses this standard

EN ISO 13354:2014 is intended for organizations involved in drilling operations where shallow gas is a risk:

• Drilling contractors and rig operators (onshore and offshore)
• Rig designers and manufacturers of diverter equipment and BOP-related components
• Safety and HSE engineers responsible for well control planning and pre-spud readiness
• Regulatory bodies and inspection agencies evaluating compliance and equipment selection
• Training providers preparing crews for shallow-gas response and pre-spud drills

Practical uses include equipment selection during tendering, design verification of diverter layouts for specific rig types (including floating supports), and establishing inspection and maintenance programs.

Related standards

• ISO 13533 - Drill-through equipment (referenced)
• API 16D - Control systems for diverter and well control equipment (referenced)
• Other well-control and drilling equipment standards may complement EN ISO 13354:2014 when developing comprehensive shallow-gas safety programs.

Keywords: EN ISO 13354:2014, shallow gas diverter equipment, diverter valves, annular sealing devices, vent outlets, diverter piping, drilling safety, onshore offshore, floating rigs.

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2014
Industrija za predelavo nafte in zemeljskega plina - Vrtalna in proizvodna oprema -
Oprema "Shallow gas diverter" (ISO 13354:2014)
Petroleum and natural gas industries - Drilling and production equipment - Shallow gas
diverter equipment (ISO 13354:2014)
Erdöl- und Erdgasindustrie - Shallow gas Diverterausrüstung (ISO 13354:2014)
Industries du pétrole et du gaz naturel - Équipements de forage et de production -
Équipement déflecteur pour gaz de surface (ISO 13354:2014)
Ta slovenski standard je istoveten z: EN ISO 13354:2014
ICS:
75.180.10 Oprema za raziskovanje in Exploratory and extraction
odkopavanje equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 13354
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2014
ICS 75.180.10
English Version
Petroleum and natural gas industries - Drilling and production
equipment - Shallow gas diverter equipment (ISO 13354:2014)
Industries du pétrole et du gaz naturel - Équipements de Erdöl- und Erdgasindustrie - Shallow gas
forage et de production - Équipement déflecteur pour gaz Diverterausrüstung (ISO 13354:2014)
de surface (ISO 13354:2014)
This European Standard was approved by CEN on 28 February 2014.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13354:2014 E
worldwide for CEN national Members.

Contents Page
Foreword .3
Foreword
This document (EN ISO 13354:2014) has been prepared by Technical Committee ISO/TC 67 "Materials,
equipment and offshore structures for petroleum, petrochemical and natural gas industries" in collaboration
with Technical Committee CEN/TC 12 “Materials, equipment and offshore structures for petroleum,
petrochemical and natural gas industries” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by November 2014, and conflicting national standards shall be withdrawn
at the latest by November 2014.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 13354:2014 has been approved by CEN as EN ISO 13354:2014 without any modification.

INTERNATIONAL ISO
STANDARD 13354
First edition
2014-05-15
Petroleum and natural gas
industries — Drilling and production
equipment — Shallow gas diverter
equipment
Industries du pétrole et du gaz naturel — Équipements de forage et
de production — Équipement déflecteur pour gaz de surface
Reference number
ISO 13354:2014(E)
©
ISO 2014
ISO 13354:2014(E)
© ISO 2014
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2014 – All rights reserved

ISO 13354:2014(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Diverter system equipment . 7
4.1 General purpose . 7
4.2 Findings of blowout reports . 7
4.3 Applications of diverter systems . 8
4.4 Layout considerations — Land rigs and bottom-supported marine structures . 8
4.5 Layout considerations — Floating rigs .18
5 Floating rigs — Specific aspects .26
5.1 Use of the marine riser .26
5.2 Additional functions of the diverter system .28
5.3 Comparison of types of floating support .28
6 Preparation for shallow gas operations .31
6.1 Call for tender .31
6.2 Important issues .31
6.3 Pre-spud checks .32
6.4 Pre-spud meetings .34
6.5 Pre-spud drills .35
6.6 Preparing the response to a shallow-gas flow .36
7 Diverter system inspection and maintenance .39
7.1 General .39
7.2 Maintenance .39
7.3 Inspection and testing .39
7.4 Diverter system piping .39
7.5 Manufacturer documentation .40
Bibliography .41
ISO 13354:2014(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 67, Petroleum and Natural gas industries,
Subcommittee SC 4, Drilling and production equipment.
iv © ISO 2014 – All rights reserved

ISO 13354:2014(E)
Introduction
Drilling into shallow-gas-bearing formations is a very delicate and challenging operation. If the drilling
operations are seriously complicated by the reduced safety margin available between kick and loss, the
situation in case of a gas influx becomes extremely hazardous, due to a combination of the following
adverse factors.
— Shallow gas flows are extremely fast-developing events; there is only a short transition time
between influx detection and well unloading, resulting in a reduced time for the driller to take the
right decision, and leaving little room for error.
— Past blowout reports have disclosed the magnitude of severe dynamic loads applied to surface
diverting equipment. One of the associated effects is erosion, which adds a high potential for fire
and explosion due to flow impingement on rig facilities which gives the gas flow access to various
sources of ignition.
— Many past shallow-gas kicks turned into uncontrolled blowouts due to the failure of former diverter
systems installed several decades ago. Failure is seen as a result of the system’s complexity, its lack
of functional reliability and its inability to cope with the severe dynamic loads.
— Certain drilling supports are exposed to specific threats associated with shallow gas blowouts, e.g.
risk of cratering, risk of ship-shaped vessel capsize.
— Unprepared or inadequately trained drilling crews experience a high level of stress when facing a
violent shallow gas flow.
In the aftermath of shallow gas blowouts during the last four decades, comprehensive inquiries and
reports have been carried out, in particular by the specialists involved in combating these events, and
significant findings and conclusions have been published. In the meantime, the manufacturing industry
has developed various equipment aimed at significantly improving the safety of shallow-gas drilling
operations.
This International Standard has been prepared taking these aspects into consideration.
INTERNATIONAL STANDARD ISO 13354:2014(E)
Petroleum and natural gas industries — Drilling and
production equipment — Shallow gas diverter equipment
1 Scope
This International Standard specifies requirements for the selection of the diverter equipment for rigs
used to drill shallow-gas-bearing formations. It covers both onshore and offshore drilling operations,
and considers also the auxiliary equipment associated with floating rigs.
The specified requirements concern the following diverter equipment:
— annular sealing devices;
— vent outlets;
— diverter valves;
— diverter piping.
This International Standard highlights the concerns associated with the selection of a marine floating
drilling support. It covers safety issues concerning key rig equipment, and important steps of action
required prior to starting the drilling operations.
It provides only general guidelines regarding the response to be given to a shallow-gas flow.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 13533, Petroleum and natural gas industries — Drilling and production equipment — Drill-through
equipment
API 16D (latest revision), Specification for Control Systems for Drilling Well Control Equipment and Control
Systems for Diverter Equipment
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
actuator
device used to open or close a valve by means of applied manual, hydraulic, pneumatic or electrical
energy
3.2
annular packing element
doughnut-shaped rubber/elastomer element that creates a seal in an annular preventer or diverter
Note 1 to entry: The annular packing element is displaced toward the bore centre by the upward movement of an
annular piston.
ISO 13354:2014(E)
3.3
annular sealing device
torus-shaped steel housing containing an annular packing element which facilitates closure of the
annulus by constricting to seal on the pipe or kelly in the wellbore
Note 1 to entry: Some annular sealing devices also facilitate shutoff of the open hole.
3.4
bag preventer
device that can seal around any object in the wellbore or upon itself
Note 1 to entry: Compression of a reinforced rubber/elastomer packing element by hydraulic pressure creates
the seal.
3.5
ball valve
valve that employs a rotating ball to open or close the flow passage
3.6
blowout
uncontrolled flow of well fluids and/or formation fluids from the wellbore or into lower-pressured
subsurface zones
Note 1 to entry: When the uncontrolled flow of fluids goes into lower-pressured subsurface zones, it is termed an
underground blowout.
3.7
blowout preventer stack
BOP stack
device that allows the well to be sealed to confine the well fluids in the wellbore
3.8
bottom-supported marine structure
drilling structure supported by the soil on the seabed while in the operating mode
Note 1 to entry: Rigs of this type include fixed platforms, submersibles, swamp barges and jack-up drilling rigs.
3.9
cleanout
point in the flow-line piping where the internal area of the pipe can be accessed to remove accumulated
debris and drill cuttings
3.10
closing unit
assemblage of pumps, valves, lines, accumulators and other items necessary to open and close the BOP
equipment and diverter system
3.11
control function
control system circuit (hydraulic, pneumatic, electrical, mechanical, or a combination thereof) used to
operate the position selection of a diverter unit, BOP, valve or regulator
EXAMPLE Diverter “close” function, starboard vent valve “open” function.
3.12
control function
each position of a diverter unit, BOP or valve and each regulator assignment that is operated by the
control system
2 © ISO 2014 – All rights reserved

ISO 13354:2014(E)
3.13
diverter
device attached to the wellhead or marine riser to close the vertical access and to direct any flow into a
set of vent lines and away from the drilling unit
3.14
diverter control system
assemblage of pumps, accumulators, manifolds, control panels, valves, lines, etc., used to operate the
diverter system
3.15
diverter housing
permanent installation under the rotary table which houses the insert-type diverter assembly
3.16
diverter packer
annular sealing device of the diverter
3.17
diverter piping
vent lines of the diverter
3.18
diverter system
assemblage, comprising an annular sealing device, flow control means, vent system components and
control system, which facilitates closure of the upward flow path of the well fluid and opening of the
vent to the atmosphere
3.19
diverter unit
device that embodies the annular sealing device and its actuating means
3.20
drill floor substructure
foundation structure on which the derrick, rotary table, draw-works and other drilling equipment are
supported
3.21
drilling spool
flanged joint placed between the BOP and casing-head that serves as a spacer or crossover
3.22
drill ship
self-propelled, floating, ship-shaped vessel equipped with drilling equipment
3.23
dump valve
device used to control bottom-riser annulus pressure by establishing direct communication with the
sea
3.24
dynamically positioned drilling vessel
DP drilling vessel
drill-ship or semi-submersible drilling rig equipped with computer-controlled thrusters which enable it
to maintain a constant position relative to a fixed point on the sea floor without the use of anchors and
mooring lines while conducting floating drilling operations
3.25
elastomer
any of various elastic compounds or substances resembling rubber
ISO 13354:2014(E)
3.26
fill-up line
line, usually connected into the bell nipple above the BOP, to allow addition of drilling fluid to the hole
while simultaneously pulling out of the hole to compensate for the metal volume displacement of the
drill string being pulled
3.27
flex/ball joint
device installed directly above the subsea BOP stack and at the top of the telescopic riser joint to permit
relative angular movement of the riser, thus reducing stresses due to vessel motions and environmental
forces
3.28
flow-line
shaker line
piping that exits the bell nipple and conducts drilling fluid and cuttings to the shale shaker and drilling
fluid pits
3.29
formation fracture pessure
value of pressure required to initiate a fracture in a subsurface formation (geologic strata)
3.30
function test
closing and opening (cycling) equipment to verify operability
3.31
gate valve
valve that employs a sliding gate to open or close the flow passage
3.32
hydrostatic head
true vertical length of fluid column
3.33
hydrostatic pressure
pressure that exists at any point in the wellbore due to the weight of the vertical column of fluid above
that point
3.34
inner barrel
part of the telescopic slip joint on a marine riser that is attached to the flex joint beneath the diverter
3.35
insert-type packer
diverter element that uses inserts designed to close and seal on specific ranges of pipe diameter
3.36
integral valve
valve embodied in the diverter unit that operates integrally with the annular sealing device
3.37
interlock
arrangement of control system functions designed to require the actuation of one function as a
prerequisite to actuate another
4 © ISO 2014 – All rights reserved

ISO 13354:2014(E)
3.38
kelly
joint of pipe with flat or fluted sides that is free to move vertically through a bushing in the rotary table
Note 1 to entry: The bushing is termed a “kelly bushing”, and it imparts torque to the kelly thereby rotating the
drill string.
3.39
kick
influx of gas, oil or other well fluids which, if not controlled, can result in a blowout
3.40
kill mud
drilling fluid with sufficient mud weight used to overcome the borehole pressure in case of well influx
3.41
knife valve
valve using a portal plate or blade to facilitate open and close operations
Note 1 to entry: A knife valve differs from a gate valve in that the bonnet area is open, i.e. not sealed.
3.42
lost circulation
loss of drilling fluid to the wellbore
3.43
marine riser
extension of the well-bore from the subsea conductor pipe housing or wellhead to the floating drilling
vessel which provides for fluid returns to the drilling vessel and guides tools into the well
3.44
moored vessel
offshore floating drilling vessel which relies on anchors, chain and mooring lines extended to the ocean
floor to maintain a constant location relative to the ocean floor
3.45
mud line
floor of an ocean, lake, bay or swamp
3.46
outer barrel
part of the telescopic slip joint on a marine riser that is attached to tensioner lines
Note 1 to entry: Tension is transferred through the outer barrel into the riser.
3.47
pre-spud
period of time which precedes the start of drilling activities
3.48
poor-boy separator
pressure vessel designed to provide effective separation of gas from drilling fluid at atmospheric
pressure while circulating out a wellbore kick through the choke manifold
3.49
primary well control
prevention of formation fluid flow by maintaining a hydrostatic pressure equal to or greater than the
formation pressure
ISO 13354:2014(E)
3.50
production platform
permanently installed bottom-supported/connected offshore structure, fitted with drilling and/or
production equipment for drilling and/or development of offshore oil and gas reservoirs
3.51
riser hydraulic connector
hydraulic latch which connects the 762 mm (30 in) conductor pipe housing and the bottom of the marine
riser
Note 1 to entry: O-ring seals prevent leaks between the latch and the housing.
3.52
rotary table
device through which the bit and drill string pass and which transmits rotational action to the kelly
3.53
subsea diverter
seabed diverter
set-up of equipment attached to the bottom of the marine riser and connected to the 762 mm (30 in)
subsea wellhead housing, designed to close the well in case of shallow-gas influx and to direct it through
two subsea lateral vent outlets
3.54
semi-submersible
floating offshore drilling vessel which is ballasted at the drilling location and conducts drilling operations
in a stable, partly submerged position
3.55
target
bull plug or blind flange at the end of a tee to reduce erosion at a point where change in flow direction
occurs
3.56
targeted
having a type of fluid piping system in which flow impinges upon a lead (or other material)-filled end
(target) or a piping tee when the fluid flow changes direction
3.57
telescopic joint packer
torus-shaped, hydraulically, pneumatically or mechanically actuated, resilient element between the
inner and outer barrels of the telescopic joint which serves to retain drilling fluid inside the marine riser
3.58
vent line
conduit that directs the flow of diverted wellbore fluids away from the drill floor and to the atmosphere
3.59
vent line valve
full-opening valve which allows passage of diverted wellbore fluids through the vent line
3.60
vent outlet
point at which fluids exit the wellbore below the annular sealing device via the vent line
3.61
wellhead
apparatus or structure, placed on the top of the casings, that supports the internal tubular, seals the well
and permits access to the casing annulus
6 © ISO 2014 – All rights reserved

ISO 13354:2014(E)
3.62
working pressure rating
WP rating
maximum internal pressure that the equipment is designed to contain or control
4 Diverter system equipment
4.1 General purpose
The diverter system is designed to permit the drilling crew to blow down shallow-gas accumulations
downwind of the rig. Until a sufficient casing length has been set to allow a well to be shut-in during a kick,
the diverter system is the only line of defence, and is only expected to contain the hazard temporarily,
although as long as possible.
The diverter system is not intended to be a well-control device. It simply allows the flow to be diverted
in a safe manner in order to allow enough time to attempt regaining primary control of the well and,
should the latter fail, enough time for proper evacuation of the drilling crew or for proper move-off of
the drilling unit from the location (floating rigs), until the flow stops due to gas accumulation blow-
down, hole bridging, hole collapse, etc.
Traditional diverter system components comprise:
— the annular sealing device;
— vent outlet(s) and vent line(s);
— valves;
— the control system.
4.2 Findings of blowout reports
Blowout inquiries have concluded that the original designs underestimated the fact that shallow-gas
blowouts produce huge amounts of gas, together with abrasive solids, flowing at very high speed,
producing severe dynamic loads, and eroding and destroying many parts of the existing diverter
systems.
The failure of these diverter systems led unfortunately to the loss of many lives.
It is therefore of paramount importance to select suitable equipment able to function in a reliable and safe
manner, i.e. able to operate whenever required under the worst possible conditions. Diverter equipment
shall also be able to cope with the prevailing dynamic loads and associated effects.
The most frequent findings from blowout reports are as follows.
— Insert-type diverters have too many components.
— The locking mechanism of insert-type diverters is not really designed to contend with severe
dynamic loads.
— Insert-type diverter packers cannot close on open-hole and on some drilling assemblies.
— Piston-actuated bag preventers are stronger and less complex, but close too slowly.
— Diverter outlets often promote erosion.
— Diverter vent lines are usually thin-walled, too small in diameter, have a tortuous path, and are
inadequately supported, fastened and secured.
— Some valve systems are inadequate and unreliable.
ISO 13354:2014(E)
— Layouts for control systems are too complex.
— Power sources of some control systems are not reliable.
— The maintenance of diverter systems is not given the same importance compared to BOPs.
4.3 Applications of diverter systems
Diverters are primarily used to divert flow from the rig in three situations:
— shallow fluid and gas flows;
— drilling with a rotating head;
— drilling with a marine riser.
This International Standard will not discuss the specific aspects associated with rotating-head drilling.
4.4 Layout considerations — Land rigs and bottom-supported marine structures
4.4.1 General
Drilling operations into shallow-gas-bearing formations include drilling from a land rig, or from a marine
structure supported by a mat-type base, by legs, or drilling from a barge that rests on the bottom, e.g.
jack-up drilling rigs, production platforms rigs and swamp-barge rigs.
Land rigs and bottom-supported marine structures have at their disposal a wide range of equipment to
build diverter arrangements.
4.4.2 Types of annular sealing devices in use
4.4.2.1 Insert-type diverter assembly
In the insert-type diverter assembly, the insert packing is latched in place into a diverter assembly, which
in turn is locked inside the support housing. This housing provides two outlets, one for the mud returns
to flow towards the shakers, one for the diverted fluids to flow out through the vent line(s). The insert is
removed prior to pulling or running the bottom-hole assembly (see Figure 1).
The rig substructure and the diverter assembly locking dogs shall be able to withstand the upward
forces of the diverted fluid.
4.4.2.2 Annular packing element
This set-up requires a conventional bag-type preventer and a drilling spool (or diverter spool) which are
directly located on top of the first casing (conductor pipe, drive pipe). This set-up is therefore below the
rotary table and below the flow-line, unlike the insert-type diverter assembly (see Figure 2).
The connections shall be in accordance with the applicable provisions of ISO 13533. The annular
packing element should be of sufficient internal diameter to pass the various bottom-hole assemblies
and casing/liner strings required for subsequent drilling operations.
NOTE For the purposes of this provision, ANSI/API 16A is equivalent to ISO 13533.
8 © ISO 2014 – All rights reserved

ISO 13354:2014(E)
Key
1 insert packing
2 piston
3 support housing
4 flow line outlet
5 vent line outlet
Figure 1 — Example of insert-type diverter assembly
ISO 13354:2014(E)
Key
1 bell nipple 6 vent line
2 flow line 7 diverter spool
3 fill-up line 8 hydraulically operated full opening valve
4 annular packing element 9 drive/conductor pipe
5 standard bag-type preventer
Figure 2 — Example of diverter assembly with annular packing element
4.4.2.3 Comparison of systems
The two systems can be compared as follows.
a) Insert-type diverter assembly
10 © ISO 2014 – All rights reserved

ISO 13354:2014(E)
— Advantages:
— quick assembly;
— flow-line, fill-up line and vent line permanently hooked up;
— faster shut-in time;
— light equipment, not cumbersome.
— Drawbacks:
— the insert-type diverter system cannot withstand more than 3 447 kPa (500 psi) beneath the
packer; this can be a problem when coping with severe gas flows;
— insert-type packer never providing complete pack-off on open hole;
— requires a significant number of valves, adding potential failure points;
— requires complex sequencing operations and interlocks to activate the vent and flow-line valves;
— requires complex control system and several power sources (pneumatic and hydraulic) to
perform the closing sequence, adding potential failure points;
— location likely to create potential erosion points in the flow-line if the latter is not properly
designed;
— overshot packer located below the diverter system, hence exposed to shallow gas flow;
— ease of hook-up is largely outweighed by the potential for failure and leaks.
b) Classical annular packing assembly
— Advantages:
— dynamic loads absorbed by the conductor pipe and the diverter system connection (clamp or
flange);
— reduced number of remotely controlled valves, due to the system position directly on top of the
first casing and below the flow-line;
— full-bore closing capacity often available;
— no more overshot packer exposed to gas flow pressure below the diverter system.
— Drawbacks:
— cumbersome equipment;
— longer nippling-up and nipple-down operations, hence including more initial expense;
— vent lines require handling and adjustment,
— excessive closing time of packing element.
4.4.2.4 Requirements for safe operation
4.4.2.4.1 General
Safe operation requires a standard hook-up including a bag-type preventer, together with a two-outlet
drilling spool, made-up straight on top of the first casing string (drive pipe, conductor pipe).
ISO 13354:2014(E)
The bag preventer shall be full-bore closing, with adequate internal diameter, and the response time
kept equal to or even below the value given in API 16D. This can be achieved by means of e.g. bigger
control lines, twin control lines, boosters.
Different sizes of bag-type preventers exist, e.g. from 508 mm to 749,3 mm (20 in to 291/2 in) with
different pressure ratings. Although it is easy to find 508 mm (20 in) bag preventers rated 13 789 kPa
(2 000 psi) working pressure (WP), the WP of most large-bore bag preventers ranges from 3 447 kPa
(500 psi) to 6 895 kPa (1 000 psi). Nevertheless, in areas where shallow-gas risk is significant, a 13 789 kPa
(2 000 psi) WP shall be considered, whatever the size of the bag-type preventer. Some manufacturers
provide 711,2 mm (28 in) equipment rated up to 13 789 kPa (2 000 psi).
The standard hook-up option eliminates the need for a flow-line valve, as the flow-line is located at the
level of the bell nipple, well above the diverter set-up.
The use of an overshot packer, required for length adjustment below the diverter system, is also
eliminated, hence removing a potential leak point at pack-off level. Conversely, this adjustment joint
and its packer can be used without risk above the bag preventer, as it will not experience any gas flow
pressure.
4.4.2.4.2 The integral diverter system
Another safe alternative is to use an integral diverter assembly, which integrates the diverter spool and
the annular packing into a single piece of equipment.
In this system the motion of the annular piston is used, in one stroke, to first open the vent lines and
then stop the upward flow. The flow-line is located at the level of the bell-nipple, well above the integral
diverter assembly, hence eliminating the need for a specific flow-line valve (see Figures 3 and 4).
An integral diverter system
— eliminates the need for a diverter spool and for the associated valves;
— reduces the number of components and functions;
— eliminates sequencing or interconnected control lines;
— eliminates the hazard associated with stagnant space;
— by design, prevents the vent lines from remaining closed while the well is already shut in;
— provides a faster shut-in time on 127 mm (5 in) drill pipes (20 s), compared to standard bag
preventers;
— provides a large wellbore of size up to 711,2 mm (28 in);
— provides one or two large-bore vent outlets of size up to 406,4 mm (16 in);
— provides high structural strength to withstand the extreme dynamic loads of shallow-gas flows.
4.4.3 Vent outlets
The vent outlets for the diverter system are located below the annular packing element.
Vent outlets may be
— incorporated in the diverter support housing, as for the insert-type diverter assembly;
— part of a drilling spool used below a conventional bag preventer;
— part of an integral diverter assembly (see Figures 3 and 4).
12 © ISO 2014 – All rights reserved

ISO 13354:2014(E)
The internal cross-sectional areas of the vent outlets shall be greater than or equal to that of the diverter
vent lines.
Design considerations for the connection between the vent outlets and vent lines should include ease of
installation, leak-free construction and freedom from solids accumulation.
3 3
a) Normal drilling operations
b) Diverting with pipe in hole
Key
1 packing unit (open position)
2 piston down
3 vent line shut in
4 packing unit (close position)
5 piston up
6 vent line open
Figure 3 — Principle of the integral diverter assembly (land and marine bottom-supported
rigs)
ISO 13354:2014(E)
Key
1 bell nipple
2 flow line
3 vent line
Figure 4 — Basic hook-up with an integral diverter assembly
4.4.4 Diverter valves
4.4.4.1 Review of equipment in use
Several types of valve are commonly associated with diverter systems: gate valves, ball valves, switchable
three-way target valves, knife valves, valves integral to the diverter unit and sometimes burst disks.
Past experience has disclosed a high potential for failure of a large number of these valves:
— failure to open/close as required when subject to gas-flow pressure and dynamic loads;
— erosion of internal surfaces;
— failure of the sequencing and interlock systems;
— clogging and blocking with trapped sediments, ice, etc.
14 © ISO 2014 – All rights reserved

ISO 13354:2014(E)
4.4.4.2 Selection criteria
Valves to be used in the diverter system shall:
— be reliable under severe shallow-gas flow conditions, i.e. be likely to work whenever required
without any likelihood of failure;
— be full-opening;
— be of equal size as the diverter vent line;
— be remotely controlled;
— be capable of opening with maximum anticipated pressure across the valve;
— be installed in such a way as to limit the space for solids to accumulate;
— be easily maintained.
4.4.4.3 Requirements for safe operation
Safe operation requires the use of hydraulically operated full-opening ball valves, driven by an
independent power source.
Valves shall be installed as close as possible to the annular sealing device, in order to minimize the space
where debris could accumulate and plug the vent lines.
For insert-type diverter systems requiring actuation of valves on both shaker and vent lines, an interlock
system shall prevent the diverter from closing before the valves are in the correct position (i.e. shaker
valve closed, vent line valve open). This is of paramount importance with these systems, where the
response time of the insert packer is much lower than that of the shaker and vent line valves [usually less
than 10 s to close on a 127 mm (5 in) drill pipe].
Actuators fitted to a diverter valve shall be sized to open the valve with the rated working pressure
(WP) of the diverter system applied across the valve.
4.4.5 Diverter piping
4.4.5.1 Pipe sizing and number
Erosion and pressure drop are major considerations in the design of diverter system piping.
Undersized and tortuous vent piping is subject to the hazardous effects of erosion due to cavitation,
impingement of fluid and solid particles, etc., as revealed from blowouts during past decades.
It also
— is subject to elevated back-pressures and consequently to leaking/failure hazards in the diverter
equipment;
— contributes significantly to an increase in the overall pressure of the well, adding the risk of
formation fracturing and possible seabed cratering.
Many rigs have undersized vent lines ranging from 152,4 mm (6 in) to 254 mm (10 in). This is often due
to the fact that models used for back-pressure calculations have widely underestimated the actual flow
conditions. In particular, critical flow effects and multiphase conditions have not been accounted for,
and shallow-gas blowout flow rates have been widely underestimated.
The consequences due to an undersized piping network are likely to be catastrophic.
The sizing requirements are mentioned in 4.4.5.7.
ISO 13354:2014(E)
4.4.5.2 Pipe material
Diverter vent lines shall be made of steel piping.
4.4.5.3 Pipe routing
At the rig design stage, routing of the vent lines shall be planned to be as straight as possible, with
no bends and branches, in order to minimize erosion, flow resistance, fluid-solid settling points and
associated back-pressures. If routing changes are unavoidable, these should be as gradual as practicable,
with a bend radius at least 20 times the inside diameter of the pipe (long-radius curvature).
For old generation rigs still having 90° bends, they shall include tees equipped with a targeted blind
flange or a targeted plug. To prevent their failure, the tees shall be purpose-manufactured to withstand
the significant loads and erosion potential from impinging well fluids. No branch is best, but use of
Y-type branches is preferable to use of tee-branch connections.
Tees and other short-radius bends (if any) shall not be located at critical places, e.g. near power rooms,
workshops or electrical rooms (see bibliography on the West Vanguard blowout report [6]).
The vent line(s) shall be sloped along its length (down, never up) to avoid low spots that can accumulate
drilling fluid and debris.
4.4.5.4 Pipe heading
At the rig site location, the diverter vent lines shall extend a sufficient distance in the most appropriate
direction from the rig to permit safe venting of diverted well fluids.
The following criteria shall be met:
— the flow
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