SIST EN ISO 20074:2019

SLOVENSKI STANDARD
01-december-2019
Industrija za predelavo nafte in zemeljskega plina - Cevovodni transportni sistemi -
Obvladovanje tveganja geoloških nevarnosti za kopenske cevovode (ISO
20074:2019)
Petroleum and natural gas industry - Pipeline transportation systems - Geological
hazards risk management for onshore pipeline (ISO 20074:2019)
Erdöl- und Erdgasindustrie - Rohrleitungstransportsysteme - Geologisches
Gefährdungsrisikomanagement für Öl- und Gasfernleitungen (ISO 20074:2019)
Industries du pétrole et du gaz naturel - Management des risques géologiques des
pipelines de gaz et de pétrole (ISO 20074:2019)
Ta slovenski standard je istoveten z: EN ISO 20074:2019
ICS:
75.200 Oprema za skladiščenje Petroleum products and
nafte, naftnih proizvodov in natural gas handling
zemeljskega plina equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 20074
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2019
EUROPÄISCHE NORM
ICS 75.020
English Version
Petroleum and natural gas industry - Pipeline
transportation systems - Geological hazards risk
management for onshore pipeline (ISO 20074:2019)
Industries du pétrole et du gaz naturel - Systèmes de Erdöl- und Erdgasindustrie -
transport par conduites - Gestion des risques Rohrleitungstransportsysteme - Geologisches
géologiques pour les conduites terrestres (ISO Gefährdungsrisikomanagement für Öl- und
20074:2019) Gasfernleitungen (ISO 20074:2019)
This European Standard was approved by CEN on 14 July 2019.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 20074:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 20074:2019) 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 NEN.
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 March 2020, and conflicting national standards shall
be withdrawn at the latest by March 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN 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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 20074:2019 has been approved by CEN as EN ISO 20074:2019 without any modification.

INTERNATIONAL ISO
STANDARD 20074
First edition
2019-07
Petroleum and natural gas industry —
Pipeline transportation systems —
Geological hazard risk management
for onshore pipeline
Industrie du pétrole et du gaz naturel — Systèmes de transport
par conduites — Gestion des risques géologiques pour les conduites
terrestres
Reference number
ISO 20074:2019(E)
©
ISO 2019
ISO 20074:2019(E)
© ISO 2019
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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CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

ISO 20074:2019(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 2
3 Terms, definitions and abbreviated terms . 2
3.1 Terms and definitions . 2
3.2 Abbreviated terms . 5
4 Pipeline geohazard risk management program . 5
4.1 Key principles . 5
4.2 Requirements for a PGMP . 5
4.3 Elements of a PGMP . 6
4.3.1 General. 6
4.3.2 Preliminary engineering and route selection phase . 7
4.3.3 Detailed design phase . . 9
4.3.4 Construction phase .10
4.3.5 Operation and maintenance phase .12
5 Risk identification .13
5.1 General .13
5.2 Geohazard inventory .17
5.3 Desktop data analysis .17
5.4 LiDAR and remote sensing imagery analysis .18
5.5 Field investigation .18
5.5.1 Field investigation techniques .18
5.5.2 Field investigation scope .18
5.5.3 Field investigation recommendations .18
5.6 Geotechnical investigation .19
6 Risk assessment .19
6.1 General .19
6.2 Assessment systems and methods.19
6.2.1 Assessment systems .19
6.2.2 Assessment methods . .20
6.3 Assessment for regional pipeline geohazard susceptibility .22
6.4 Assessment for individual pipeline geohazard .22
7 Risk mitigation .23
7.1 General .23
7.2 Mitigations .23
7.2.1 Physical and procedural mitigations .23
7.2.2 Short-term and long-term mitigation measures .24
8 Techniques and methods for geohazard risk management .25
9 Data management .28
Annex A (informative) Guidelines for pipeline route selection .29
Annex B (informative) Field investigation recommendations .31
Annex C (informative) Example of classification of geological environmental conditions by
complexity level .33
Annex D (informative) Example qualitative assessment method .35
Annex E (informative) Example semi-quantitative assessment method .45
Annex F (informative) Potential methods to mitigate risk .54
ISO 20074:2019(E)
Annex G (informative) Some key influencing factors of selected geohazards .61
Bibliography .66
iv © ISO 2019 – All rights reserved

ISO 20074:2019(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 2, Pipeline
transportation systems.
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 20074:2019(E)
Introduction
This document is used by pipeline operators and designers for the implementation and improvement of
geohazard risk management of onshore pipelines.
It is used for the orderly and effective identification, assessment and mitigation of geohazards
threatening the integrity or safety of the pipeline, and to reduce the potential for risks and accident
loss. This document is intended to address geohazards along the pipeline and right-of-way (RoW).
vi © ISO 2019 – All rights reserved

INTERNATIONAL STANDARD ISO 20074:2019(E)
Petroleum and natural gas industry — Pipeline
transportation systems — Geological hazard risk
management for onshore pipeline
1 Scope
This document specifies requirements and gives recommendations on the management of geohazard
risks during the pipeline design, construction and operational periods.
This document is applicable to all operators and pipelines (existing and proposed/under construction).
This document applies to onshore gathering and transmission pipelines used in the petroleum and
natural gas industries.
NOTE This document is not applicable to piping and pipelines within well-defined plants and facilities,
such as pump or compressor stations, processing facilities or refineries. It is assumed that the facility site as a
whole will be subject to a separate geohazard assessment to evaluate applicable natural and man-made hazards.
Nevertheless, this document can provide useful guidance for assessing the geohazard threat to facilities,
including the pipelines within the facility.
This document is applicable to all reasonable and credible natural hazards induced by natural forces
and hazards induced by human activity that manifest similarly to natural hazards collectively referred
to as “geological hazards” or “geohazards”, or through industry as attributed to “natural forces”.
Geohazards covered by this document include, but are not limited to (not given in order of significance):
— mass wasting processes, including landslides, lateral spreads, rockfalls, debris flows, avalanches,
and similar processes whether naturally occurring or anthropogenic;
— land subsidence and/or sinkhole formation, whether naturally occurring such as from dissolution
of salt or carbonate rock formations (karst formation) or human caused, such as from underground
mining or withdrawal of subsurface fluids such as groundwater and oil and gas;
— seismic hazards, such as ground shaking, fault rupture, liquefaction, flow failures and lateral
spreading or associated secondary effects, such as seismically triggered landslides;
— volcanic hazards, such as lahars, pyroclastic flows, lava flows, dam break, and volcanically induced
seismicity (excluding ashfall), where such hazards can be reasonably predicted;
— hydrologic processes, such as flooding, vertical scour of river bottoms, channel migration and bank
erosion, channel avulsion, rapid lake drainage;
— permafrost/periglacial processes and geothermal effects, such as thermal degradation, frost heave
or thaw settlement, thermal erosion, thermokarst;
— surface (overland), trench backfill, or earthwork fill erosion;
— expansion or collapsing processes caused by expansive and collapsible soils, such as glaciomarine
clays, collapsible loess, etc.
This document is not applicable to atmospheric/environmental effects, such as the following:
— high winds induced from hurricanes and tornadoes and similar storms, except where such events
are reasonably predictable and will induce geohazards such as landslides, erosion, etc.;
— lightning;
— forest or brush fires;
ISO 20074:2019(E)
— ashfall from volcanic eruptions.
Furthermore, this document is not applicable to cascading events, where one remote event leads to a
chain of events that eventually induces a geohazard near the pipeline. It is only applicable to geohazards
that directly affect the pipeline or RoW.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and abbreviated terms
3.1 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/
3.1.1
construction phase
period where the pipeline is physically constructed encompassing all activities from RoW clearing, to
commissioning and RoW clean-up/reinstatement
3.1.2
detailed design phase
period consisting of detailed design, which can include but is not limited to detailed hydraulic studies,
mechanical design of the pipeline, stress analysis, design of RoW, full characterization of all identified
geohazards, construction and logistics planning, and supply management
3.1.3
dynamic management
process that covers the pipeline’s full life cycle, which can be implemented when a new hazard is
identified or an existing hazard changed
3.1.4
geohazard inventory
list of all identified geohazards which can be maintained, enhanced or decreased throughout the life of
the pipeline project
Note 1 to entry: Ideally, the inventory would be computer based and linked to a Geographic Information
System (GIS).
3.1.5
geohazard susceptibility
geological or environmental conditions that might allow a geohazard event to occur
Note 1 to entry: A geohazard event can be natural or man-made occurrence that induces an integrity or safety
threat to the pipeline or RoW.
3.1.6
geologically sensitive area
area potentially prone to geohazards
EXAMPLE Such areas include seismic fault zones or active faults, medium and large rivers, high and steep
slopes, debris flows corridors, landslide prone topography, areas prone to karst collapse, mined-out areas.
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ISO 20074:2019(E)
3.1.7
hydrologic process
process associated with flowing water, i.e. river and stream processes
3.1.8
individual pipeline geohazard
specific geohazard that can impact the pipeline
3.1.9
land subsidence
sinking or gradual downward settling of the earth’s surface with relatively little horizontal movement
Note 1 to entry: It can be caused by karst processes, collapsible or dispersive soils, piping erosion, upward
migration of underground mining works, or other processes.
3.1.10
long-term management
management activities for pipeline geohazards (3.1.15) through monitoring and periodic re-evaluation
of threat levels from geohazards
3.1.11
mass wasting process
general term for the dislodgement and gravity-driven downslope movement or transport of soil and
rock material
3.1.12
operation and maintenance phase
period in pipeline lifecycle during which hydrocarbon product fills the pipeline and is transported
through the pipeline, and the pipeline operator addresses issues related to pipeline and RoW
maintenance and integrity
3.1.13
operator
person or organization which owns or operates a pipeline system or facilities and which is responsible
for the operation and integrity of the pipeline system
3.1.14
pipeline failure consequence
impact or loss caused directly or indirectly by leakage, damage or reduced performance of a pipeline
subject to geohazards
EXAMPLE Social and environmental impact, loss of life and property, negative impact on corporate
reputation, and economic loss.
Note 1 to entry: This includes individual pipeline geohazard and regional pipeline geohazard.
3.1.15
pipeline geohazard
geological process or phenomenon that have the potential to cause damage to a pipeline or RoW
3.1.16
pipeline geohazard risk
combination of geohazard susceptibility (3.1.5), pipeline vulnerability (3.1.22) and pipeline failure
consequence (3.1.14)
3.1.17
pipeline geohazard risk assessment
process of determining whether pipeline geohazard risks (3.1.16) are acceptable or require mitigation
or an intervention
ISO 20074:2019(E)
3.1.18
pipeline geohazard risk identification
process of discovery, characterization and description of credible and probable geohazards that can
impact the pipeline or RoW
3.1.19
pipeline geohazard risk management
coordinated activity for guiding and coping with issues related to pipeline geohazard risk (3.1.16)
3.1.20
pipeline geohazard risk management program
set of processes and procedures for guiding operating companies or operators (3.1.13) to carry out
pipeline geohazard risk management (3.1.19)
3.1.21
pipeline geohazard risk mitigation
process of selecting and implementing a geohazard risk countermeasure or intervention to reduce
the probability of a negative event or reduce the consequences of a negative event that can impact the
pipeline or RoW
3.1.22
pipeline vulnerability
conditional likelihood of a pipeline being subject to damage due to a geohazard, given a geohazard
occurs and impacts the pipeline, which is an estimate of how resistant it is to damage caused by
geohazards
3.1.23
preliminary engineering and route selection phase
initial period in the pipeline lifecycle during which basic design work is completed, including but not
limited to route study and selection, preliminary design of the pipeline, early planning for logistics,
supply management and regulatory planning and submissions
3.1.24
regional pipeline geohazard
group or cluster of existing and potential geohazards located within a defined geographic area
3.1.25
right-of-way
corridor of land within which the pipeline operator has the right to conduct activities in accordance
with the agreement of the land owner
[SOURCE: ISO 13623:2017, 3.1.19]
3.1.26
seismic hazard
hazard occurring as a result of an earthquake
3.1.27
subject matter expert
SME
practitioner experienced with evaluating and managing geohazards
Note 1 to entry: The qualifications for a subject matter expert vary by location but they generally include a degree
in geology, geomorphology, hydrogeology, geotechnical engineering, geological engineering, civil engineering, or
related degree and at least five years of practical experience working with geohazards.
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ISO 20074:2019(E)
3.2 Abbreviated terms
GIS Geographic Information System
ILI In-Line Inspection
LiDAR Light Detection and Ranging
PGMP Pipeline Geohazard Risk Management Program
RoW Right-of-way
4 Pipeline geohazard risk management program
4.1 Key principles
A PGMP is a set of practices and procedures used to systematically identify, evaluate, and manage
geohazards for the purposes of reducing the risk of damage to a pipeline system to an acceptable level.
A PGMP is operated for the entire lifespan of the pipeline from conception and design, to construction,
operation, and until the pipeline system is decommissioned. Thus, the PGMP should be designed and
implemented in such a way that critical information will be maintained and accessible for the lifetime
of the pipeline.
Because a variety of different groups participate in the design, construction and operation of a pipeline,
overall ownership of the PGMP rests with the operator. The operator shall designate an individual or
organization (the “PGMP team”) to administer the PGMP during and between the different phases. The
PGMP team may be the operator’s personnel or a qualified third party entrusted by the operator. In case
of replacement of one organization by another, a proper handover of geohazard risk management duties
shall be ensured. When the geohazard risk management is assigned to a third party, the operator shall
be continuously and intimately engaged with the third party to ensure that the interests and needs of
the operator and all stakeholders are being adequately addressed and protected.
It is recommended that geohazard risk management throughout the life of a pipeline be carried out by
the same organization, which can be either an operator, or a third party entrusted by them.
Dynamic management of pipeline geohazards is required and newly identified geohazards may be
included in said management. Geohazards included in dynamic management are referred to as risk
management objects.
Where a PGMP is needed, operators shall establish and maintain a PGMP for the life of the asset.
Operator shall update the PGMP during the life of the asset as and when conditions warrant.
All work associated with the geohazard risk identification, assessment and mitigation of the pipeline
shall be carried out by qualified personnel. SMEs shall be consulted as necessary throughout all stages
and phases of the pipeline lifecycle.
PGMP activities shall be documented. Geohazards might change over time, and changes in the PGMP
shall be documented over time, to ensure that the most current data and assessments are identified.
Out-of-date assessments may be archived.
4.2 Requirements for a PGMP
The PGMP informs an operator of how to design, construct and operate the pipeline in a safe,
environmentally responsible and reliable manner.
The PGMP covers the phases of preliminary engineering and route selection, detailed design, construction,
as well as operation and maintenance. It is recommended to conduct geohazard risk management as a
discrete element of the pipeline design phase, beginning in the earliest phases of design.
ISO 20074:2019(E)
Geohazard risks to a pipeline, and thus the need and scope of a PGMP, varies from pipeline to pipeline,
due to a number of natural and human-induced factors. Geohazard risk might be higher for pipelines
operated in areas of
a) steep terrain,
b) active tectonics,
c) high precipitation,
d) soluble bedrock,
e) high seismicity,
f) geologically young terrain,
g) significant natural resource exploitation/extraction,
h) landslide prone geology,
i) volcanism,
j) active shallow mining,
k) significant river crossings, and
l) geothermal variability such as permafrost.
For example, a short pipeline in a flat, tectonically stable region with minimal rainfall might have a
relatively low geohazard risk. In this case, the operator might demonstrate that a PGMP is not needed.
Conversely a long pipeline with a 50-year service life, in a remote, steep, tectonically active tropical
region would likely have a relatively high geohazard risk. In this case, the operator would very likely
establish a PGMP.
Because of the broad variation in geohazard risk between pipelines, an operator is required to assess
geohazard risk of existing and future pipelines and determine whether a PGMP is necessary.
If an operator concludes that a PGMP is not necessary for a particular pipeline or section of pipeline, the
conclusion shall be documented. The documentation shall be a report titled:
Demonstration that Geohazard Management Program is not Required for [name of pipeline].
It shall include, without limitation, a discussion of the items listed in 4.2 a) to l) with an explanation
why the geohazard risks are of such a low level that a PGMP is not needed. The report shall be prepared
in consultation with suitable SMEs with appropriate experience in the region and type of geology in
which the pipeline is, or will be installed.
If an operator concludes that a PGMP is necessary, the operator shall establish a PGMP team to design
and implement the appropriate PGMP, beginning at the earliest phases of project development.
4.3 Elements of a PGMP
4.3.1 General
To prevent and reduce risks caused by geohazards, the PGMP shall be carried out throughout the life of
a pipeline under the guidance of the PGMP team. The PGMP covers four interlinked processes:
— identification of potential geohazards;
— evaluation of the severity of the geohazards;
— mitigation of the threat from the geohazards;
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ISO 20074:2019(E)
— long-term management of geohazards through monitoring and periodic re-evaluation of threat
levels from geohazards.
The four processes are needed to varying degrees throughout the life of the pipeline.
To illustrate the application of the four processes, this document considers four phases of pipeline life:
— preliminary engineering and route selection;
— detailed design;
— construction;
— operation and maintenance.
Each phase is discussed below, with an illustration of the four processes within each phase.
A typical PGMP follows the flowchart in Figure 1. The PGMP process shall occur in parallel with
consideration of other constraints, such as economics and societal.
4.3.2 Preliminary engineering and route selection phase
In this phase, the effects of geohazards shall be fully considered to meet the requirements of route
selection. Because the most effective mitigation of geohazards is avoidance, this phase represents an
important opportunity for the operator to reduce the overall geohazard risk of the project.
Annex A provides guidelines for route selection in consideration of geohazards.
During this phase, the PGMP shall follow the principles of identification, evaluation, mitigation and
long-term management:
— Identification: Establish regional understanding of geohazards and determine whether regional
geohazard threat level requires further development of a PGMP. For the initial corridor alternatives,
severe geohazards and geologically sensitive areas, such as seismic fault zones or active faults,
medium and large rivers, high and steep slopes, debris flows corridors, landslide prone topography,
areas prone to karst collapse, mined-out areas should be identified. Acquire regional and local
remote sensing data sets, supplement with ground investigation if warranted. Light Detection and
Ranging (LiDAR) data combined with expert interpretation have proven to be an extremely valuable
tool in identifying geohazards during this phase.
— Evaluation: Classify geohazards along the proposed corridors according to severity of their threat
to the proposed pipeline. Some geohazards might be found to be sufficiently severe that they create
critical conditions and could cause a candidate corridor to be removed from consideration. Other
geohazards pose less severe risk. The locations, footprints and severity of the geohazards shall be
assembled in a GIS database, and shall form the geohazard inventory (5.2) that will exist for the life
of the project.
— Mitigation: The primary mitigation of geohazards at this phase is avoidance. An important
responsibility of the PGMP team at this phase is the unambiguous assessment and presentation of
geohazards and risks to the broader project team. Quantification of geohazard impacts on design,
construction and operations is helpful to fully define the risks. The selection of the final corridor shall
consider the impacts of geohazards, balanced against other design, construction and operational
considerations. At this stage, the operator may also consider other mitigations, e.g. strain-based
design of the pipe.
— Long-term management: Because no asset yet exists, long-term management of geohazards at this
stage consists of developing the geohazard inventory and associated GIS database, and passing it to
the detailed design phase.
The recommended implementation procedures in this phase are:
a) Establish regional understanding of geohazards and determine corridor alternatives.
ISO 20074:2019(E)
b) Select a primary corridor.
c) For the primary corridor, perform regional geohazard susceptibility assessment (6.3). If warranted,
individual geohazard risk assessments (6.4) might be necessary for specific locations.
d) Following selection of the primary corridor, the detailed design phases may begin.
NOTE Considerable pipeline design work, such as pipeline hydraulic studies, construction method studies,
logistics and supply assessments and other activities are also being performed in this phase.
Key
1 preliminary engineering and route selection phase
2 detailed design phase
3 construction phase
4 operation and maintenance phase
Figure 1 — A PGMP flowchart
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ISO 20074:2019(E)
4.3.3 Detailed design phase
Detailed design may be conducted by an entity other than the operator. Compared to the previous phase,
this phase typically involves a larger project team, more resources, increased ability and complexity of
field works, and increased definition of project objectives. All of these activities can benefit the PGMP.
The PGMP shall again follow the four primary principles:
— Identification: Identification will begin with the geohazard inventory developed during the
previous phase, and enhance the inventory with additional investigation, both remote sensing and
ground-based. Consideration should be given to both the proposed primary pipeline corridor, as
well as potential re-routes, ancillary and temporary facilities such as quarries, camps and access
roads that might be required for pipeline construction.
— Evaluation: Existing items in the geohazard inventory shall be re-classified as new data become
available, and all additional geohazard items shall be classified. Field and remote data gathering
programs shall be designed in part to enable this evaluation. Remote and on-ground monitoring
of geohazards may also commence during this phase. Inclinometers may be installed at ground
movement locations, and monitoring plans developed. Rainfall and riverflow gauges may also be
installed as access to the site improves. Evaluation of geohazard risks specifically to construction,
including off-RoW impacts, shall be evaluated by the PGMP team in collaboration with the project’s
execution specialists.
— Mitigation: The primary mitigation of geohazard risk remains avoidance. In this phase, re-routing
shall be used to avoid geohazards, balanced with other project objectives such as constructability,
cost, environmental and stakeholder considerations. During this phase, other on-RoW mitigations,
such as reduced footprint (narrow RoW), ground reinforcement and soil drains, may also be
developed. Consideration shall also be given to incorporating mitigations such as strain-based
design and geotechnical and integrity monitoring into the design. Adequate seismic design shall be
considered for pipelines crossing seismic fault zones or active faults. References [6], [9], [10], [18],
[19], [20] and [21] provide guidance for the seismic design of pipeline.
— Long-term management: Long-term management of geohazards at this stage consists of further
developing the geohazard inventory and associated GIS database, and passing it to the construction
phase. Locations and data from monitoring locations, as well plans for RoW and pipe mitigations,
shall also be passed to the construction phase.
Note that
— pipeline geohazard risk management requirements shall be regarded as one of the bases for
optimizing pipeline design scheme and making decisions, along with other pipeline design factors
determined in the preliminary engineering and route selection phase,
— each identified geohazard shall be assessed to determine its impact on pipeline and environmental
integrity, and
— mitigation shall be proposed for geohazards that have an unacceptable or unmitigated impact.
The recommended implementation procedures in this phase are:
a) Start risk identification for the primary corridor selected in the preliminary engineering and route
selection phase or alternative corridors proposed by design department or as a result of public/
stakeholder consultations.
b) Perform risk assessment on regional and individual geohazards.
c) Repeat steps a), and b) above until all identified geohazards have an acceptable level of risk,
achieved through re-routing or application of appropriate mitigations.
d) Prepare PGMP interface with constructor. If detailed design and construction are performed by the
same entity, this will be an internal interface.
ISO 20074:2019(E)
e) This phase should be repeated if during or after the evaluation of the potential for geohazard
occurrence significantly changes, such as from human activity (e.g. mining or road construction),
strong storms (e.g. a tropical cyclone), or large earthquake.
4.3.4 Construction phase
NOTE Subclause 4.3.4 is written as though the pipeline designer and constructor were different entities.
If they were the same entity, some of the guidance on interfaces could still apply, although these interfaces are
internal to the entity rather than external between entities. In either case, it is ultimately the responsibility
of operator through the PGMP team to ensure that the PGMP is properly transitioned from detailed design to
construction phases.
Pipeline construction in geohazard-susceptible areas carries increased risk to personnel. The pipeline
constructor should be made aware of geohazard risk level during the tender phase. In particular, the
tender package prepared should describe the duties expected of the constructor under the PGMP.
Construction of a pipeline in a geohazard environment is a unique phase in the life of the asset, and
therefore a unique phase of the PGMP. Some important considerations include the following:
— The relatively large number of personnel on the RoW during the construction phase will result in
increased risk of personal injury due to geohazards.
— The RoW will be fully cleared of most vegetation, enabling a better examination of ground and
geohazard conditions, and allowing for on-ground examination of some features that were
previously only identified by remote sensing. Care should be taken as ground clearing might
promote erosion and slope instability.
— The availability of personnel, machinery and logistical support such as transportation and camps,
is relatively high. In addition, the presence of personnel and machinery at the construction site
presents the ideal time to identify new undetected geohazards and implement geohazards
mitigations.
— RoW preparation
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