SIST-TP CEN ISO/TR 19905-2:2014
(Main)Petroleum and natural gas industries - Site-specific assessment of mobile offshore units - Part 2: Jack-ups commentary and detailed sample calculation (ISO/TR 19905-2:2012)
Petroleum and natural gas industries - Site-specific assessment of mobile offshore units - Part 2: Jack-ups commentary and detailed sample calculation (ISO/TR 19905-2:2012)
ISO/TR-2 19905 provides a commentary to some clauses of ISO 19905-1 including background information, supporting documentation, and additional or alternative calculation methods as applicable and also provides a detailed sample 'go-by' calculation. ISO 19905-1 specifies requirements and guidance for the site-specific assessment of independent leg jack-up units for use in the petroleum and natural gas industries.
Erdöl- und Erdgasindustrie - Offshore Anlagen; Beurteilung von mobilen Offshore Einheiten bezüglich ihres Einsatzgebietes - Teil 2: Hubinseln, Erläuterungen (ISO/TR 19905-2:2012)
Industries du pétrole et du gaz naturel - Évaluation liée au site des unités marines mobiles - Partie 2: Compléments sur les plates-formes auto-élévatrices (ISO/TR 19905-2:2012)
Industrija za predelavo nafte in zemeljskega plina - Ocenjevanje mobilnih naftnih ploščadi na področju postavitve - 2. del: Dvižne ploščadi, razlaga in podroben vzorčen izračun (ISO 19905-2:2012)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TP CEN ISO/TR 19905-2:2014
01-marec-2014
,QGXVWULMD]DSUHGHODYRQDIWHLQ]HPHOMVNHJDSOLQD2FHQMHYDQMHPRELOQLKQDIWQLK
SORãþDGLQDSRGURþMXSRVWDYLWYHGHO 'YLåQHSORãþDGLUD]ODJDLQSRGUREHQ
Y]RUþHQL]UDþXQ ,62
Petroleum and natural gas industries - Site-specific assessment of mobile offshore units -
Part 2: Jack-ups commentary and detailed sample calculation (ISO/TR 19905-2:2012)
Erdöl- und Erdgasindustrie - Offshore Anlagen; Beurteilung von mobilen Offshore
Einheiten bezüglich ihres Einsatzgebietes - Teil 2: Hubinseln, Erläuterungen (ISO/TR
19905-2:2012)
Industries du pétrole et du gaz naturel - Évaluation liée au site des unités marines
mobiles - Partie 2: Compléments sur les plates-formes auto-élévatrices (ISO/TR 19905-
2:2012)
Ta slovenski standard je istoveten z: CEN ISO/TR 19905-2:2013
ICS:
75.180.10 Oprema za raziskovanje in Exploratory and extraction
odkopavanje equipment
SIST-TP CEN ISO/TR 19905-2:2014 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST-TP CEN ISO/TR 19905-2:2014
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SIST-TP CEN ISO/TR 19905-2:2014
TECHNICAL REPORT
CEN ISO/TR 19905-2
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
December 2013
ICS 75.180.10
English Version
Petroleum and natural gas industries - Site-specific assessment
of mobile offshore units - Part 2: Jack-ups commentary and
detailed sample calculation (ISO/TR 19905-2:2012)
Industries du pétrole et du gaz naturel - Évaluation liée au Erdöl- und Erdgasindustrie - Offshore Anlagen; Beurteilung
site des unités marines mobiles - Partie 2: Compléments von mobilen Offshore Einheiten bezüglich ihres
sur les plates-formes auto-élévatrices (ISO/TR 19905- Einsatzgebietes - Teil 2: Hubinseln, Erläuterungen (ISO/TR
2:2012) 19905-2:2012)
This Technical Report was approved by CEN on 11 May 2013. It has been drawn up by the Technical Committee CEN/TC 12.
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
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TR 19905-2:2013 E
worldwide for CEN national Members.
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SIST-TP CEN ISO/TR 19905-2:2014
CEN ISO/TR 19905-2:2013 (E)
Contents Page
Foreword .3
2
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SIST-TP CEN ISO/TR 19905-2:2014
CEN ISO/TR 19905-2:2013 (E)
Foreword
This document (CEN ISO/TR 19905-2:2013) 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.
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.
Endorsement notice
The text of ISO/TR 19905-2:2012 has been approved by CEN as CEN ISO/TR 19905-2:2013 without any
modification.
3
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SIST-TP CEN ISO/TR 19905-2:2014
TECHNICAL ISO/TR
REPORT 19905-2
First edition
2012-12-15
Petroleum and natural gas industries —
Site-specific assessment of mobile
offshore units —
Part 2:
Jack-ups commentary and detailed
sample calculation
Industries du pétrole et du gaz naturel — Évaluation liée au site des
unités marines mobiles —
Partie 2: Compléments sur les plates-formes auto-élévatrices
Reference number
ISO/TR 19905-2:2012(E)
©
ISO 2012
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SIST-TP CEN ISO/TR 19905-2:2014
ISO/TR 19905-2:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing 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 copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved
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SIST-TP CEN ISO/TR 19905-2:2014
ISO/TR 19905-2:2012(E)
Contents Page
Foreword .v
Introduction.vii
1 Scope.1
2 References .1
3 Terms and definitions .1
4 Symbols.1
4.1 Symbols for Clause 6.1
4.2 Symbols for Clause 7.3
4.3 Symbols for Clause 8.5
4.4 Symbols for Clause 9.6
4.5 Symbols for Clause 10.6
4.6 Symbols for Clause 12.8
5 Commentary on ISO 19905-1:2012, Clauses 5 and A.5 .8
6 Commentary on ISO 19905-1:2012, Clauses 6 and A.6 .8
TR.6.4.1 Metocean data — General.8
TR.6.4.2 Waves .8
TR.6.4.3 Current.20
TR.6.4.4 Water depths.20
TR.6.4.5 Wind .21
7 Commentary to ISO 19905-1:2012, Clauses 7 and A.7 .24
TR.7.1 Scope .24
TR.7.3.2 Hydrodynamic model .24
TR.7.3.2.1.1 Length of members .24
TR.7.3.2.1.2 Spudcan.24
TR.7.3.2.1.3 Shielding and solidification.24
TR.7.3.2.2 “Detailed” leg model .25
TR.7.3.2.3 “Equivalent” leg model .25
TR.7.3.2.3.1 Equivalent drag coefficient.25
TR.7.3.2.3.2 Equivalent inertia coefficient.26
TR.7.3.3 Wave and current actions.48
TR.7.3.4 Wind actions .57
TR.7.8 Other considerations.57
APPENDIX TR.7.A : Example of equivalent model computations.58
APPENDIX TR.7.B: Comparison cases to assess implications of the ISO 19905-1 formulation .63
APPENDIX TR.7.C: Comparison of test results for chords.67
8 Commentary to ISO 19905-1:2012, Clauses 8 and A.8 .70
TR A.8.8.6 Derivation of the alternative simplified negative stiffness correction term for P-∆
effects .70
9 Commentary to ISO 19905-1:2012, Clauses 9 and A.9 .77
TR.9.3.6.2 Derivation of the limiting horizontal reaction given in ISO 19905-1:2012, Table A.9.3.7 .77
10 Commentary to ISO 19905-1:2012, Clauses 10 and A.10 .79
TR.10.4.2.1 Natural period — General .79
TR.10.4.2.2 Derivation of K , effective stiffness used to calculate the jack-up natural period.82
e
TR.10.4.3.3 Hysteretic damping .95
TR.10.4.3.4 Vertical radiation damping in earthquake analysis .96
TR.10.5.3.4 / C.2.4 Guidance on the fourth method of ISO 19905-1:2012, Table A.10.5.1 —
Application of the drag-inertia method .96
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ISO/TR 19905-2:2012(E)
11 Commentary to ISO 19905-1:2012, Clauses 11 and A.11.96
12 Commentary to ISO 19905-1:2012, Clauses 12 and A.12.96
TR.12.6.2.2 Nominal bending strength .96
TR.12.6.2.2.1 Example .96
TR.12.6.3.2 Background for η in interaction equation approach.97
13 Commentary to ISO 19905-1:2012, Annex C .98
TR.C.2.4 Guidance on the fourth method of ISO 19905-1:2012, Table A.10.5.1 — Application of
the drag-inertia method.98
Annex A (informative) Detailed example calculation.99
Annex B (informative) SIPM “drag-inertia method” for dynamic analysis and estimation of
extreme response for jack-ups.266
Bibliography .295
iv © ISO 2012 – All rights reserved
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SIST-TP CEN ISO/TR 19905-2:2014
ISO/TR 19905-2:2012(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In exceptional circumstances, when a technical committee has collected data of a different kind from that
which is normally published as an International Standard (“state of the art”, for example), it may decide by a
simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely
informative in nature and does not have to be reviewed until the data it provides are considered to be no
longer valid or useful.
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.
ISO/TR 19905-2 was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore
structures for petroleum, petrochemical and natural gas industries, Subcommittee SC 7, Offshore structures.
ISO 19905 consists of the following parts, under the general title Petroleum and natural gas industries — Site-
specific assessment of mobile offshore units:
⎯ Part 1: Jack-ups
⎯ Part 2: Jack-ups commentary and detailed sample calculation [Technical Report]
The following part is under preparation:
⎯ Part 3: Floating units
ISO/TR 19905-2:2012 was prepared in 2012 and is referenced as ISO/TR 19905-2:2012. Users are advised,
however, that it was published, and only became available, in 2013.
ISO 19905 is one of a series of International Standards for offshore structures. The full series consists of the
following International Standards:
⎯ 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 19901-2, Petroleum and natural gas industries — Specific requirements for offshore structures —
Part 2: Seismic design procedures and criteria
⎯ ISO 19901-3, Petroleum and natural gas industries — Specific requirements for offshore structures —
Part 3: Topsides structure
© ISO 2012 – All rights reserved v
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SIST-TP CEN ISO/TR 19905-2:2014
ISO/TR 19905-2:2012(E)
⎯ ISO 19901-4, Petroleum and natural gas industries — Specific requirements for offshore structures —
Part 4: Geotechnical and foundation design considerations
⎯ ISO 19901-5, Petroleum and natural gas industries — Specific requirements for offshore structures —
Part 5: Weight control during engineering and construction
⎯ ISO 19901-6, Petroleum and natural gas industries — Specific requirements for offshore structures —
Part 6: Marine operations
⎯ ISO 19901-7, Petroleum and natural gas industries — Specific requirements for offshore structures —
Part 7: Stationkeeping systems for floating offshore structures and mobile offshore units
1)
⎯ 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
⎯ ISO 19903, Petroleum and natural gas industries — Fixed concrete offshore structures
⎯ ISO 19904-1, Petroleum and natural gas industries — Floating offshore structures — Part 1: Monohulls,
semi-submersibles and spars
⎯ ISO 19905-1, Petroleum and natural gas industries — Site-specific assessment of mobile offshore
units — Part 1: Jack-ups
⎯ ISO/TR 19905-2, Petroleum and natural gas industries — Site-specific assessment of mobile offshore
units — Part 2: Jack-ups commentary and detailed sample calculation
1)
⎯ ISO/TR 19905-3 , Petroleum and natural gas industries — Site-specific assessment of mobile offshore
units — Part 3: Floating units
⎯ ISO 19906, Petroleum and natural gas industries — Arctic offshore structures
1) Under preparation.
vi © ISO 2012 – All rights reserved
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SIST-TP CEN ISO/TR 19905-2:2014
ISO/TR 19905-2:2012(E)
Introduction
The series of International Standards applicable to types of offshore structures, ISO 19900 to ISO 19906,
addresses design requirements and assessments for all offshore structures used by the petroleum and natural
gas industries worldwide. Through their application, the intention is to achieve reliability levels appropriate for
manned and unmanned offshore structures, whatever the type of structure and the nature or combination of
the materials used.
It is important to recognize that structural integrity is an overall concept comprising models for describing
actions, structural analyses, design or assessment rules, safety elements, workmanship, quality control
procedures and national requirements, all of which are mutually dependent. The modification of one aspect of
the design or assessment in isolation can disturb the balance of reliability inherent in the overall concept or
structural system. The implications involved in modifications, therefore, need to be considered in relation to
the overall reliability of offshore structural systems.
The series of International Standards applicable to the various types of offshore structure is intended to
provide a wide latitude in the choice of structural configurations, materials and techniques without hindering
innovation. Sound engineering judgement is therefore necessary in the use of these International Standards.
[5]
ISO 19905-1 was developed from SNAME T&R Bulletin 5-5A , but has been considerably altered from that
original document. Some of the alterations have involved a restructuring and modification of terminology, but
there have been additional changes of greater technical consequence. New material has been added based
on studies undertaken since the original development of SNAME T&R 5-5A; new calculation techniques have
been addressed because of improved computational capabilities allowing more complex assessments; gaps
that existed in the original SNAME T&R 5-5A have been filled, thereby ensuring a more thorough assessment;
and changes have been made to align ISO 19905-1 with other standards within the 19900 series. A
description of the more important changes, along with the reasoning for the changes, can be found in a series
of papers published in 2012 by Offshore Technology Conference. These papers can be of considerable value
in helping the analyst, particularly those who are familiar with SNAME T&R 5-5A, in understanding
ISO 19905-1. The papers, part of the Technical Session ISO 19905-1: A Site-Specific Assessment of Mobile
Jack-Up Units are listed in the Bibliography:
⎯ Reference [6], Background to the ISO 19905-Series and an Overview of the New ISO 19905-1 for the
Site-Specific Assessment of Mobile Jack-Up Units
⎯ Reference [7], Environmental Actions in the New ISO for the Site-Specific Assessment of Mobile Jack-Up Units
⎯ Reference [8], Structural Modeling and Response Analysis in the New ISO Standard for the Site-Specific
Assessment of Mobile Jack-Up Units
⎯ Reference [9], Foundation Modeling and Assessment in the New ISO Standard 19905-1
⎯ Reference [10], Long-Term Applications in the ISO Standard for Site Specific Assessment of Mobile
Jack-Up Units and the Use of Skirted Spudcans
⎯ Reference [11], Structural Acceptance Criteria in the New ISO for the Site-Specific Assessment of Mobile
Jack-Up Units
⎯ Reference [12], The Benchmarking of the New ISO for the Site-Specific Assessment of Mobile Jack-Up Units
This part of ISO 19905, which has been developed from SNAME T&R Bulletin 5-5A, provides a commentary
to some clauses of ISO 19905-1 including background information, supporting documentation, and additional
or alternative calculation methods as applicable and also provides a detailed sample “go-by” calculation in
Annex A. The reader is advised that the information presented herein is intended for use in conjunction with
ISO 19905-1 and that the cautions and limitations discussed in ISO 19905-1 apply.
© ISO 2012 – All rights reserved vii
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SIST-TP CEN ISO/TR 19905-2:2014
TECHNICAL REPORT ISO/TR 19905-2:2012(E)
Petroleum and natural gas industries — Site-specific
assessment of mobile offshore units —
Part 2:
Jack-ups commentary and detailed sample calculation
1 Scope
This part of ISO 19905 provides a commentary to some clauses of ISO 19905-1 including background
information, supporting documentation, and additional or alternative calculation methods as applicable and
also provides a detailed sample 'go-by' calculation. ISO 19905-1 specifies requirements and guidance for the
site-specific assessment of independent leg jack-up units for use in the petroleum and natural gas industries.
2 References
The following referenced documents are indispensable for the application 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 19905-1:2012, Petroleum and natural gas industries — Site-specific assessment of mobile offshore
units — Part 1: Jack-ups
3 Terms and definitions
For the purposes of this document the terms and definitions given in ISO 19905-1 apply.
4 Symbols
4.1 Symbols for Clause 6
C drag coefficient
D
C D equivalent drag coefficient times effective diameter
De e
d water depth
D depth attenuation
2
D(θ ) directional spreading function from ISO 19901-1
F(α) directional spreading function from SNAME
f frequency (Hz)
g acceleration due to gravity
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SIST-TP CEN ISO/TR 19905-2:2014
ISO/TR 19905-2:2012(E)
H wave height
H reduced wave height which may be used in deterministic/regular wave force calculations
det
H maximum wave height for a given return period; used for airgap calculations
max
H wave height associated with H , equivalent to the height between the extreme crest and the
mpm srp
following trough
H estimate of H significant wave height (metres)
mo s
H scaled significant wave height to be used in irregular seas simulation (metres)
s
H significant wave height for assessment return period
srp
k wave number
2m
m power constant in the ⎡⎤cos α spreading function
()
⎣⎦
S (f) power density of wave surface elevation as a function of wave frequency
nn
T wave period (seconds)
T wind averaging time (seconds)
T standard reference time averaging interval for wind speed of 1 h = 3 600 s
0
T peak period in wave spectrum (seconds)
p
T zero-upcrossing period of wave spectrum (seconds)
z
U wind speed
U (10) is the sustained wind speed at 10 m height above mean sea level
w,T
U is the 1 h sustained wind speed at the reference elevation 10 m above mean sea level
w0
u the computed velocity for long crested waves
u the reduced horizontal velocity
red
V current velocity
α equilibrium range parameter
α skewness
3
α kurtosis
4
γ peak enhancement factor
γ scaling of drag forces
d
κ kinematics reduction factor
η crest elevation by Airy theory
2 © ISO 2012 – All rights reserved
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SIST-TP CEN ISO/TR 19905-2:2014
ISO/TR 19905-2:2012(E)
η crest elevation by Stokes
s
φ directional spreading factor defined in ISO 19901-1
σ spectral peakwidth parameter
4.2 Symbols for Clause 7
A cross-sectional area of member
A equivalent area of leg per unit height
e
A equivalent area of element
i
A sum of projected areas for all members in the considered plane
s
A total projected envelope area of the considered plane
t
C added mass coefficient
A
C drag coefficient
D
C drag coefficient for chord at direction θ = 0°
Do
C drag coefficient for flow normal to the rack, θ = 90°
D1
C equivalent drag coefficient
De
C equivalent drag coefficient of member i
Dei
C drag coefficient of an individual member, related to D
Di i
C (θ ) drag coefficient to the projected diameter
Dpr
C drag coefficient for a rough member
Drough
C drag coefficient for a smooth member
Dsmooth
C inertia coefficient
M
C equivalent inertia coefficient
Me
C equivalent inertia coefficient of member i
Mei
C inertia coefficient of a member, related to D
Mi i
d mean, undisturbed water depth (positive)
D member diameter
D equivalent diameter of leg bay
e
D face width of leg, outside dimensions
F
D reference dimension of individual leg members
i
D (θ) projected diameter of the chord
pr
f fundamental vibration frequencies of the member
i
H significant wave height
s
© ISO 2012 – All rights reserved 3
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SIST-TP CEN ISO/TR 19905-2:2014
ISO/TR 19905-2:2012(E)
k roughness height
k/D relative roughness
KC Keulegan-Carpenter number
l length of member “i” node to node
i
m added mass contribution (per unit length) for the member
a
N constant in wind velocity power law
�
r velocity of the considered member, normal to the member axis and in the direction of the
n
combined particle velocity
�� acceleration of the considered member, normal to the member axis and in the direction of the
r
n
combined particle velocity
Re Reynolds number
s length of one bay, or part of bay considered
S Strouhal number
S average wave steepness
S outer diameter of an array of tubulars
T wave period
T first natural period of sway motion
n
T zero-upcrossing period
z
u particle velocity
u particle velocity normal to the member
n
u� particle acceleration normal to the member
n
u , u� horizontal water particle velocity and acceleration
x
x
U flow velocity at the depth of the considered element
U current particle velocity
C
U maximum orbital particle velocity
m
U reduced particle velocity for regular waves
red
U representative wave particle velocity
W
v total flow velocity normal to the member
n
V reduced current velocity for use in the hydrodynamic model; V should not be taken as less than
C C
0,7V
f
V current velocity normal to member used in the hydrodynamic model
Cn
V far field (undisturbed) current
f
4 © ISO 2012 – All rights reserved
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SIST-TP CEN ISO/TR 19905-2:2014
ISO/TR 19905-2:2012(E)
W dimension from backplate to pitch point of triangular chord or dimension from root of one rack to
tip of other rack of split tubular chord
W width of the structure
z coordinate measured vertically upward from the mean water surface
z′ modified coordinate to be used in particle velocity formulation
α indicator for relative velocity, 0 or 1
α angle defining flow direction r
...
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