ABS 279-2017 GUIDE FOR CONVERSION OF SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS.pdf

1、 Guide for Conversion of Self- Elevating Units to Offshore Installations GUIDE FOR CONVERSION OF SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS JUNE 2017 American Bureau of Shipping Incorporated by Act of Legislature of the State of New York 1862 2017 American Bureau of Shipping. All rights reserved

2、. ABS Plaza 16855 Northchase Drive Houston, TX 77060 USA Foreword Foreword Converting a self-elevating unit to an offshore installation can be a cost effective option for developing an offshore field. When converting a self-elevating unit to an offshore installation, the classification of the existi

3、ng self-elevating unit as a mobile unit is to be changed to be classified as a site-specific offshore installation. This Guide provides guidance and specifies the classification requirements for converting self-elevating units to offshore installations. The marine and safety systems may be included

4、within ABSs scope of classification if they are requested to be classed by the Owner. The jacking system is to be included in ABSs scope of classification until the unit is on station. The jacking system will remain a part of class if it is kept active, giving the ability to jack up or down and hold

5、ing on station, or it is requested to be kept within class by the Owner. This Guide is to be used in conjunction with the ABS Rules for Building and Classing Mobile Offshore Drilling Units and the ABS Rules for Building and Classing Offshore Installations. This Guide becomes effective on the first d

6、ay of the month of publication. Users are advised to check periodically on the ABS website www.eagle.org to verify that this version of this Guide is the most current. We welcome your feedback. Comments or suggestions can be sent electronically by email to rsdeagle.org. ii ABSGUIDE FOR CONVERSION OF

7、 SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS .2017 Table of Contents GUIDE FOR CONVERSION OF SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS CONTENTS SECTION 1 General 5 1 Introduction . 5 3 Governmental Regulations . 5 5 Operating Manual . 5 7 Documentation 5 9 Application of Rules 6 11 Reference

8、s 6 13 Abbreviations 6 SECTION 2 Scope and Conditions of Classification . 7 1 Classification Notations and Options 7 3 Scope of Classification 7 3.1 Minimum Design Life . 7 3.3 Offshore Installation Classification 7 SECTION 3 Structures and Hydrostatic Stability 8 1 General . 8 1.1 Initial Structura

9、l Condition 8 1.3 Materials and Welding . 8 1.5 Environmental Conditions 8 3 Structural Design Requirements . 8 3.1 General 8 3.3 Design and Assessment of Structure 8 3.5 Loads 9 5 Overturning Stability 10 7 Preload 10 7.1 Capability . 10 7.3 Leg Strength 10 9 Subdivision and Stability . 10 11 Incli

10、ning Experiment 10 13 Earthquakes 10 ABSGUIDE FOR CONVERSION OF SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS .2017 iii SECTION 4 Foundations 11 1 General . 11 3 Mat Type Foundation 11 5 Individual Leg Footing (Spudcan) Foundation 11 SECTION 5 Jacking System 12 1 General . 12 1.1 Jacking System not

11、 Included in Class . 12 1.3 Jacking System Included in Class . 12 SECTION 6 Hydrocarbon Production and Process Systems . 13 1 General . 13 SECTION 7 Surveys . 14 1 Surveys during Conversion . 14 3 Surveys during Installation and System Start-Up and Commissioning . 14 5 Surveys after Construction 14

12、iv ABSGUIDE FOR CONVERSION OF SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS .2017 Section 1: General SECTION 1 General 1 Introduction This Guide provides guidance for converting Self-Elevating Units (SEUs) to Offshore Installations (OIs) for Hydrocarbon Production and/or Processing service. Where a

13、 SEU is converted to an OI, the classification requirements of this Guide are to be complied with, and the ABS Offshore Installation notation will be granted when found satisfactory. If the marine and safety systems serving the entire installation are requested to be classed by the Owner, ABSs scope

14、 of classification work is to include the marine and safety systems and compliance with applicable ABS Rules and/or Guides, as referenced in 7-2-A3/3 of ABS Rules for Building and Classing Mobile Offshore Drilling Units (MODU Rules), is required. If non-structural items of the installation are exclu

15、ded from ABSs scope of classification, and if the jacking system is only to be used during the initial jacking of the unit on site, the jacking system at a minimum is to be restricted to an examination to confirm the systems ability to elevate the unit to the required elevation at the final location

16、 in accordance with Section 5. A calculation is to be submitted confirming that the units final total load to be lifted does not exceed the jacking unit rated capacity. Upon satisfactory review and survey, ABS will issue documentation to the unit for a single voyage from the conversion yard to the i

17、nstallation site. After the installation is completed and the Surveyor is satisfied, a report will be submitted to the Class Committee requesting issuance of a full term Class Certificate. 3 Governmental Regulations It is recognized that an Offshore Installation is typically sited in the jurisdictio

18、n of one or more governmental authorities. ABS, at the request of the Operator and where recognized by the pertinent governmental authorities, may modify the scope of classification and apply criteria that conform to the technical standards specified by the governmental authority for the purposes of

19、 granting classification. 5 Operating Manual An Operating Manual is to be submitted to verify changes to the design information and limitations considered in the conversion of the unit. The Operating Manual is to contain the information listed in Section 1-1-5 of the MODU Rules as applicable. The ma

20、nual is to be placed aboard the unit for the guidance of the operating personnel. The primary language of the Operating Manual is to be English. ABS is not responsible for the operation of the unit. 7 Documentation The documentation needed to verify the acceptability of the structure, equipment and

21、systems for the selected scope of classification is to be provided for review. Reference is to be made to documentation requirements in the applicable Rules. The documentation is to include drawings, analyses, testing and inspection reports, material certificates, reports on geotechnical and other g

22、round conditions, reports on the long-term environmental conditions at the operating site and those needed to assess conditions during transport and installation, and seismic condition where applicable, etc. ABSGUIDE FOR CONVERSION OF SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS .2017 5 Section 1

23、General 9 Application of Rules References are made in this Guide to ABS publications and industry standards. The application of these Rules and Guides is based on the contract date of conversion between the shipbuilder and the Owner. 11 References i) ABS Rules for Building and Classing Mobile Offsho

24、re Drilling Units (MODU Rules) ii) ABS Rules for Building and Classing Offshore Installations (OI Rules) iii) ABS Rules for Building and Classing Facilities on Offshore Installations (Facilities Rules) iv) ABS Guide for the Fatigue Assessment of Offshore Structures (Offshore Fatigue Guide) v) ABS Gu

25、ide for Building and Classing Subsea Riser Systems (Riser Guide) vi) ABS Rules for Conditions of Classification Offshore Units and Structures (Part 1) vii) ABS Rules for Materials and Welding (Part 2) viii) ABS Guidance Notes on Structural Analysis for Self-Elevating Units ix) ISO 19905-1, Petroleum

26、 and natural gas industries Site-specific assessment of mobile offshore units Part 1: Jack-ups, 2012 Where a particular edition or date associated with a reference is given, it means that particular edition is relevant to the topic being presented in this Guide. Use of a later edition may be permitt

27、ed upon consultation with ABS. ABS may consider at its discretion, upon the request of the Owner, the application of other appropriate alternative methods and recognized codes of practice. 13 Abbreviations ABS American Bureau of Shipping ISO International Organization for Standardization LCG Longitu

28、dinal Center of Gravity OI Offshore Installation SEU Self-Elevating Unit TCG Transverse Center of Gravity VCG Vertical Center of Gravity 6 ABSGUIDE FOR CONVERSION OF SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS .2017 Section 2: Conversion with Deactivated Jacking System SECTION 2 Scope and Conditi

29、ons of Classification 1 Classification Notations and Options When converting a SEU to an OI, the classification of the existing SEU as a mobile unit is to be changed to be classified as a site-specific offshore installation. The design is to be based on site-specific conditions of the operating site

30、 where the unit is to be installed and operated in the elevated condition. The existing unit being converted was built under the supervision of ABS Surveyors to the requirements of these Rules or to their equivalent, where approved by the Classification Committee, will be classed and distinguished i

31、n the Record by the symbols A1 Offshore Installation. The basic scope of classification can be expanded to include the Hydrocarbon Production and/or Process Facilities and/or the Hydrocarbon Import and Export systems by applying the criteria contained in the ABS Rules for Building and Classing Facil

32、ities on Offshore Installations (Facilities Rules) and/or the ABS Guide for Building and Classing Subsea Riser Systems (Riser Guide). Satisfaction of the relevant criteria will result in the granting of the following classification notations: A1 Offshore Installation Hydrocarbon Production A1 Offsho

33、re Installation Hydrocarbon Processing A1 Offshore Installation Offshore Risers If the existing unit being converted was built under ABS class, then the would be maintained for the converted offshore installations. For existing units constructed under survey of another recognized Classification Soci

34、ety or Authority, the Maltese Cross symbol will be omitted. 3 Scope of Classification 3.1 Minimum Design Life The design life for future service is not to be less than 5 years. Prior service is to be suitably accounted for when determining the available future service life (i.e., consideration shoul

35、d be given to repairs, renewals, weld improvement, fatigue damage, wastage (erosion and corrosion), remaining anode mass, condition of coatings, etc.). 3.3 Offshore Installation Classification 3.3.1 Structure Design Criteria The design criteria in the Rules for Building and Classing Offshore Install

36、ations (OI Rules) along with the MODU Rules are to be applied to the main structures listed in 3/3.3. The structures are subject to design review, survey during conversion and future surveys to maintain classification. 3.3.2 Other Major Considerations In addition to the structural items mentioned ab

37、ove, the following major items are to be considered: i) The intact and damage stability of the platform structure in the wet tow condition, see Subsections 3/9 and 3/11. ii) Preloading and overturning stability, see Subsections 3/5 and 3/7. iii) Foundation, see Section 4. ABSGUIDE FOR CONVERSION OF

38、SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS .2017 7 Section 3 : Structures and Hydrostatic Stability SECTION 3 Structures and Hydrostatic Stability 1 General 1.1 Initial Structural Condition Since the Installation is considered to be a conversion of an existing self-elevating unit, the effects of

39、 corrosion, erosion, renewals, repairs, modifications, fatigue damage, etc. are to be taken into account in the review of hull scantlings and the assessment of the structure after conversion for the loads expected during: i) The transport of the Installation to the operating site. ii) The offshore e

40、levation, assembly and commissioning process. iii) The Offshore Installation service life. 1.3 Materials and Welding The materials used in the original construction and those to be used for structural modifications are to be clearly identified. The existing material is to be checked for the service

41、temperature at the intended installation site. The new material is to be selected in accordance with the ABS Rules for Material and Welding (Part 2). Welding is to be done in accordance with the ABS Rules for Material and Welding (Part 2). The design of hull welds are to be in accordance with the MO

42、DU Rules. Other welds are to be designed in accordance with Subsection 3/3. 1.5 Environmental Conditions The specification and determination of site-specific environmentally-induced loads are to be in accordance with Part 3, Section 1 of the OI Rules. In particular, refer to 3/1.5.1 and 3/1.5.2 of t

43、he OI Rules regarding the “Design Environmental” and “Operating Environmental” Conditions, respectively. 3 Structural Design Requirements 3.1 General The applicable portions of the Part 3, Section 3 and Part 3, Section 4 of the OI Rules are to be used for the design of steel structures. The referenc

44、ed sections of the OI Rules are to be applied, except where the use of the MODU Rules criteria is explicitly specified therein. 3.3 Design and Assessment of Structure 3.3.1 Design Criteria The design criteria of the OI Rules apply to the following structural items: i) Hull and leg structures ii) Fou

45、ndation structures (individual spudcans or mat foundation) iii) Leg to hull connections iv) Deckhouses v) Helideck 8 ABSGUIDE FOR CONVERSION OF SELF-ELEVATING UNITS TO OFFSHORE INSTALLATIONS .2017 Section 3 Structures and Hydrostatic Stability vi) Appurtenant Structure, see 3-2-2/11 of the MODU Rule

46、s where applicable vii) Hydrocarbon Production and Process related structure (e.g., flare structure and its foundation) viii) The individual skids and frames directly supporting the production equipment ix) Module underdeck support structures x) Riser porches or foundations 3.3.2 Design and Assessme

47、nt The design and assessment of the structure are to include the following: i) The adequacy of the initial scantlings of the major structural elements and deckhouses are to be assessed in accordance with 3-2-3/3.3 and 3-2-3/15 of the MODU Rules. ii) The structural assessments of the pertinent struct

48、ures are to be conducted using the acceptance criteria in Part 3, Section 1 through Part 3, Section 4 of the OI Rules. The legs and spudcans are to be assessed in accordance with Subsection 3/7 of this Guide for the pre-load condition and 3-2-3/7.3 of the MODU Rules for the wet tow condition as appl

49、icable. iii) The wave-induced dynamic response is to be assessed according to 3-2-3/5.9 of the MODU Rules. Reference can be made to the ABS Guidance Notes on the Structural Analysis of Self-Elevating Units. iv) The adequacy of the soil condition at the intended site is to be assessed in accordance with Part 3, Section 6 of the OI Rules. v) The strength of structures listed in 3/3.3.1 for Hydrocarbon Production and Process Systems is to be assessed in accordance with 3/4.9 and 3/4.13 of the OI Rules. vi) If structural assembly will be performed offshore at the i