oSIST prEN ISO 3421:2021

Petroleum and natural gas industries - Drilling and production equipment - Offshore conductor design, setting depth and installation (ISO/FDIS 3421:2022)

This document gives requirements for the design, setting depth and installation of conductors used by the offshore petroleum and natural gas industries. This document covers:
-   design of the conductor, i.e. determination of the diameter, wall thickness, and steel grade;
-   determination of the setting depth for three installation methods, namely, driving, drilling/cementing, and jetting;
-   installation requirements for the installation methods, i.e. selection principles, operating procedures and parameters.
This document is applicable to:
-   Platform conductors: installed through a guide hole in the platform drill floor and then through guides attached to the jacket at appropriate intervals through the water column to support the conductor withstand metocean actions and prevent excessive displacements.
-   Jack-up supported conductors: a temporary conductor used only during drilling operations, which is installed by a jack-up drilling rig. In some cases, the conductor is tensioned by tensioners attached to the drilling rig.
-   Free-standing conductors: a self-supporting caisson in cantilever mode installed in shallow water, typically depths of about 10 m to 20 m. It provides sole support for the well and sometimes supports a small access deck and boat landing.
-   Subsea wellhead conductors: a fully submerged conductor extending only a few metres above the seafloor.
This document does not apply to drilling risers.

Erdöl- und Erdgasindustrie - Bohr- und Förderausrüstung - Offshore-Leiterauslegung, Setztiefe und Einbau (ISO/FDIS 3421:2022)

Industries du pétrole et du gaz naturel - Équipements de forage et de production - Conception, profondeur de pose et installation des tube-guides en mer (ISO/FDIS 3421:2022)

Industrija za predelavo nafte in zemeljskega plina - Vrtalna in proizvodna oprema - Načrtovanje plavajočih vodnikov, nastavitev globine in vgradnja (ISO/FDIS 3421:2022)

General Information

• Status: Not Published
• Public Enquiry End Date: 18-Jul-2021
• ICS: 75.180.10 - Exploratory, drilling and extraction equipment
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 09-Mar-2022
• Due Date: 27-Apr-2022
• Ref Project: FprEN ISO 3421 - Petroleum and natural gas industries - Drilling and production equipment - Offshore conductor design, setting depth and installation (ISO/FDIS 3421:2022)

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN ISO 3421:2021
01-julij-2021

Industrija za predelavo nafte in zemeljskega plina - Vrtalna in proizvodna oprema -

Načrtovanje plavajočih vodnikov, nastavitev globine in vgradnja (ISO/DIS
3421:2021)

Petroleum and natural gas industries - Drilling and production equipment - Offshore

conductor design, setting depth, and installation (ISO/DIS 3421:2021)

Erdöl- und Erdgasindustrie - Bohr- und Förderausrüstung - Offshore-Leiterauslegung,

Setztiefe und Einbau (ISO/DIS 3421:2021)
Ta slovenski standard je istoveten z: prEN ISO 3421
ICS:
75.180.10 Oprema za raziskovanje, Exploratory, drilling and
vrtanje in odkopavanje extraction equipment
oSIST prEN ISO 3421:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 3421:2021
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oSIST prEN ISO 3421:2021
DRAFT INTERNATIONAL STANDARD
ISO/DIS 3421
ISO/TC 67/SC 4 Secretariat: ANSI
Voting begins on: Voting terminates on:
2021-04-26 2021-07-19
Petroleum and natural gas industries – Drilling and
production equipment – Offshore conductor design, setting
depth, and installation
ICS: 75.180.10
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 3421:2021(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2021
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oSIST prEN ISO 3421:2021
ISO/DIS 3421:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
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Phone: [phone]
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Published in Switzerland
ii © ISO 2021 – All rights reserved
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oSIST prEN ISO 3421:2021
ISO/DIS 3421:2021(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 2

4 Abbreviated terms and symbols .......................................................................................................................................................... 3

4.1 Abbreviated terms ............................................................................................................................................................................... 3

4.2 Symbols for conductor design ................................................................................................................................................... 3

4.3 Symbols for setting depth .............................................................................................................................................................. 4

5 General requirements ..................................................................................................................................................................................... 6

5.1 General ........................................................................................................................................................................................................... 6

5.2 Contents ........................................................................................................................................................................................................ 6

5.2.1 Basic data ............................................................................................................................................................................... 6

5.2.2 Conductor design............................................................................................................................................................. 6

5.2.3 Setting depth ....................................................................................................................................................................... 7

5.2.4 Installation requirements ........................................................................................................................................ 7

5.3 Design situations ................................................................................................................................................................................... 7

5.3.1 General...................................................................................................................................................................................... 7

5.3.2 Operational design situations ............................................................................................................................... 7

5.3.3 Extreme design situations ....................................................................................................................................... 8

5.4 Use of this document ......................................................................................................................................................................... 8

6 Basic data ..................................................................................................................................................................................................................... 8

6.1 General ........................................................................................................................................................................................................... 8

6.2 Metocean and ice parameters .................................................................................................................................................... 8

6.3 Soil parameters ....................................................................................................................................................................................... 8

6.4 Engineering design parameters ............................................................................................................................................... 9

6.4.1 Platform parameters .................................................................................................................................................... 9

6.4.2 Drilling, completion and production design parameters .............................................................. 9

7 Conductor design ..............................................................................................................................................................................................10

7.1 General ........................................................................................................................................................................................................10

7.2 Actions .........................................................................................................................................................................................................10

7.2.1 General...................................................................................................................................................................................10

7.2.2 Permanent actions (G) .............................................................................................................................................10

7.2.3 Metocean and ice actions .......................................................................................................................................11

7.2.4 Thermal annulus pressure build-up action ...........................................................................................11

7.3 Factored actions ..................................................................................................................................................................................11

7.4 Boundary restraints .........................................................................................................................................................................12

7.4.1 General...................................................................................................................................................................................12

7.4.2 Platform conductors ..................................................................................................................................................12

7.4.3 Jack-up supported conductors ..........................................................................................................................12

7.4.4 Free-standing conductors .....................................................................................................................................12

7.4.5 Subsea wellhead conductors ..............................................................................................................................13

7.5 Strength and stability checks ...................................................................................................................................................13

7.5.1 Design method ................................................................................................................................................................13

7.5.2 Axial compression .......................................................................................................................................................13

7.5.3 Bending .................................................................................................................................................................................14

7.5.4 Shear ........................................................................................................................................................................................15

7.5.5 Combined stress ............................................................................................................................................................16

7.6 Fatigue .........................................................................................................................................................................................................16

8 Setting depth ..........................................................................................................................................................................................................17

8.1 General ........................................................................................................................................................................................................17

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oSIST prEN ISO 3421:2021
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8.2 Setting depth for drilling fluid circulation channel ..............................................................................................17

8.3 Setting depth for wellbore foundation bearing structure ..............................................................................18

8.3.1 General...................................................................................................................................................................................18

8.3.2 Installation by driving or drilling/cementing ......................................................................................18

8.3.3 Installation by jetting ................................................................................................................................................22

9 Installation ..............................................................................................................................................................................................................24

9.1 General ........................................................................................................................................................................................................24

9.2 Driving .........................................................................................................................................................................................................24

9.2.1 Applicability ......................................................................................................................................................................24

9.2.2 Driveability analysis ...................................................................................................................................................24

9.2.3 Installation procedures ...........................................................................................................................................24

9.2.4 Data documentation ..................................................................................................................................................25

9.3 Drilling/cementing ...........................................................................................................................................................................25

9.3.1 Applicability ......................................................................................................................................................................25

9.3.2 Size match of bit and conductor ......................................................................................................................25

9.3.3 Wait on cement...............................................................................................................................................................26

9.4 Jetting ...........................................................................................................................................................................................................26

9.4.1 Applicability ......................................................................................................................................................................26

9.4.2 Size match of bit and conductor ......................................................................................................................26

9.4.3 Jetting bottom hole assembly ............................................................................................................................26

9.4.4 Jetting operating parameters .............................................................................................................................27

9.4.5 Installation quality requirements ..................................................................................................................27

Annex A (informative) Calculation methods for fracture pressure of seabed soil ............................................28

Annex B (informative) Calculation methods for ultimate bearing capacity of seabed soil ......................30

Annex C (informative) Installation sequence for platform conductors when driving ...................................33

Annex D (informative) Calculation of bit stick out when jetting ..........................................................................................35

Bibliography .............................................................................................................................................................................................................................37

iv © ISO 2021 – All rights reserved
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oSIST prEN ISO 3421:2021
ISO/DIS 3421:2021(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 of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore

structures for petroleum, petrochemical and natural gas industries, Subcommittee SC 4, Drilling and

production equipment.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2021 – All rights reserved v
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oSIST prEN ISO 3421:2021
ISO/DIS 3421:2021(E)
Introduction

This document is applicable to conductors utilized by the offshore petroleum and natural gas industries.

It provides requirements and guidance on the design, setting depth, and installation of offshore

conductors, without hindering innovation. Sound engineering judgment is necessary in the use of this

document.

Conductor design addresses actions and action combinations, strength and stability checks, and

fatigue analysis. Setting depth provides calculation methodologies for different installation methods.

Installation addresses selection of the installation method, and of procedures and operation parameters.

Annex A provides calculation methods for fracture pressure of seabed soil.

Annex B provides calculation methods for ultimate bearing capacity of seabed soil.

Annex C provides a means to optimize platform conductor installation sequence when driving

considering pile group effect.
Annex D provides a method for determining the bit stick-out when jetting.
vi © ISO 2021 – All rights reserved
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oSIST prEN ISO 3421:2021
DRAFT INTERNATIONAL STANDARD ISO/DIS 3421:2021(E)
Petroleum and natural gas industries – Drilling and
production equipment – Offshore conductor design, setting
depth, and installation
1 Scope

This document gives requirements for the design, setting depth and installation of conductors used by

the offshore petroleum and natural gas industries. This document covers:

— design of the conductor, i.e. determination of the diameter, wall thickness, and steel grade;

— determination of the setting depth for three installation methods, namely, driving, drilling/

cementing, and jetting;

— installation requirements for the installation methods, i.e. selection principles, operating procedures

and parameters.
This document is applicable to:

— Platform conductors: installed through a guide hole in the platform drill floor and then through

guides attached to the jacket at appropriate intervals through the water column to support the

conductor withstand metocean actions and prevent excessive displacements.

— Jack-up supported conductors: a temporary conductor used only during drilling operations, which

is installed by a jack-up drilling rig. In some cases, the conductor is tensioned by tensioners attached

to the drilling rig.

— Free-standing conductors: a self-supporting caisson in cantilever mode installed in shallow water,

typically depths of about 10 m to 20 m. It provides sole support for the well and sometimes supports

a small access deck and boat landing.

— Subsea wellhead conductors: a fully submerged conductor extending only a few metres above the

seafloor.
This document does not apply to drilling risers.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 19900, Petroleum and natural gas industries — General requirements for offshore structures

ISO 19901-1, Petroleum and natural gas industries — Specific requirements for offshore structures —

Part 1: Metocean design and operating considerations

ISO 19901-4, Petroleum and natural gas industries — Specific requirements for offshore structures —

Part 4: Geotechnical and foundation design considerations

ISO 19901-8, Petroleum and natural gas industries — Specific requirements for offshore structures —

Part 8: Marine soil investigations

ISO 19902, Petroleum and natural gas industries — Fixed steel offshore structures

API RP 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems

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oSIST prEN ISO 3421:2021
ISO/DIS 3421:2021(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
bearing capacity
capacity of conductor to resist vertical action effects without soil failure

Note 1 to entry: Bearing capacity can be divided into initial bearing capacity, real-time bearing capacity and

ultimate bearing capacity, based on the interaction time between the conductor and the soil. Initial bearing

capacity refers to the capacity immediately after installation; real-time bearing capacity refers to the capacity

after a period of time; and ultimate bearing capacity refers to the capacity when the soil recovers its strength

before disturbance.
3.2
conductor
outermost casing and foundation of offshore oil and gas well
3.3
design situation
set of physical conditions for which the conductor (3.2) is verified

Note 1 to entry: The design situations typically addressed are operational design situations that occur during

installation and normal use of the conductor, and extreme design situations that occur rarely during the use of

the conductor. Extreme design situations include survival conditions, e.g. the emergency capping condition for a

subsea wellhead conductor.
3.4
effective weight
weight in sea water or drilling fluid
3.5
metocean action
effect of wind, wave and current on a conductor

Note 1 to entry: The determination of these effects includes the influence of marine growth, tide, surge, and

related processes, as appropriate.
3.6
seabed

materials below the seafloor, whether of soil such as sand, silt or clay, cemented materials or of rock

[SOURCE: ISO 19901-4:2016, 3.15]
3.7
seafloor
interface between the sea and the seabed
[SOURCE: ISO 19901-4:2016, 3.16]
3.8
setting depth
depth-into-seabedvertical depth from the seafloor to the conductor shoe

Note 1 to entry: A minimum setting depth is set to provide sufficient bearing capacity to ensure formation

integrity at the conductor shoe during the surface drilling phase.
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oSIST prEN ISO 3421:2021
ISO/DIS 3421:2021(E)
3.9
undrained shear strength
maximum shear strength in the undrained condition
4 Abbreviated terms and symbols
4.1 Abbreviated terms
APB annulus pressure build-up
BHA bottom hole assembly
BOP blowout preventer
WOB weight on bit
WOC wait on cement
4.2 Symbols for conductor design
cross-sectional area of the conductor
C moment reduction factor
outer diameter of the conductor
D a non-dimensional number
Young’s modulus of elasticity
E extreme quasi-static metocean action due to wind, waves and current

E metocean action due to owner defined operating wind, wave and current parameters

F factored design actions
f representative bending strength
f representative axial compressive strength
f Euler buckling strength
f representative shear strength
f representative yield strength
permanent action
moment of inertia of the conductor’s cross-section
effective length factor
K local experience factor
unbraced length of the conductor
L calculated fatigue life
maximum bending moment on the cross-section due to factored actions
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oSIST prEN ISO 3421:2021
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N number of cycles to failure under constant amplitude stress range
number of cycles of stress range
Q thermal annulus pressure build-up (APB) action
conductor’s radius of gyration
time period over which Palmgren-Miner’s sum was determined
wall thickness of the conductor
U utilization of the conductor
shear due to factored actions
Z elastic section modulus
Z plastic section modulus
σ bending stress due to forces from factored actions
σ axial compressive stress due to forces from factored actions
τ shear stress due to forces from factored actions
γ partial action factor for permanent actions

partial action factor of which the value reflects the uncertainty or randomness of the action

(in accordance with ISO 19900)
γ a fatigue damage design factor
γ partial resistance factor for bending strength
Rb,
partial resistance factor for axial compressive strength
Rc,
γ partial resistance factor for shear strength
Rv,
4.3 Symbols for setting depth
A the side surface area of the conductor in soil
outer diameter of the conductor
d surface section drilling fluid (mud) density
mud
FF, partial safety factors
ss12
F axial force in the conductor
xial

F axial force applied to the conductor during the surface casing installation stage

xsur
axial force applied to the conductor after the surface casing cementing
xsur
F axial force applied to the conductor during the BOP installation stage
xBOP

F axial force applied to the conductor during the subsequent casings and tubing installation stage

xst

F axial force applied to the conductor in the wellhead and christmas tree installation stage

xwt
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oSIST prEN ISO 3421:2021
ISO/DIS 3421:2021(E)
F axial force applied to the conductor in the extreme design situation
xcap
() unit skin friction
G conductor effective self-weight
con
acceleration of gravity
setting depth for a jetted conductor

h minimum setting depth of the conductor meeting the circulation channel function

min
K axial stiffness of the conductor
con

K axial stiffness of the coupled foundation composed of the surface casing and the conductor

K stif
...