1、 Guidance Notes on Subsea Hybrid Riser Systems GUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS JANUARY 2017 American Bureau of Shipping Incorporated by Act of Legislature of the State of New York 1862 2016 American Bureau of Shipping. All rights reserved. ABS Plaza 16855 Northchase Drive Houston, TX 7
2、7060 USA Foreword Foreword These Guidance Notes describe suggested practice for the design, materials, testing, manufacturing, installation and maintenance of hybrid riser systems to be classed or certified by ABS. These Guidance Notes are to be used in conjunction with other Rules and Guides publis
3、hed by ABS as specified herein, in particular the ABS Guide for Building and Classing Subsea Riser Systems. During the preparation of these Guidance Notes, ABS recognized that industry participation is a vital factor both to the rapidly progressing nature of this technology, and for the success of d
4、eveloping an appropriate standard which satisfies practical classification requirements. ABS appreciates the industrys input in the development of these Guidance Notes. These Guidance Notes reflect the latest technology developments and industry practice for hybrid riser systems for deepwater instal
5、lation. These Guidance Notes indicate detailed guidance for hybrid riser systems from configuration selection, engineering design to offshore installation. This does not exclude the use of other practices for a hybrid riser system, provided that relevant industrial design codes are followed, sound e
6、ngineering practice is implemented, and justification for the use is adequately documented. Riser design engineers are encouraged to consult fabrication and installation specialists to establish the presence of constraints that will affect the design. These Guidance Notes become effective on the fir
7、st day of the month of publication. Users are advised to check periodically on the ABS website www.eagle.org to verify that this version of these Guidance Notes is the most current. We welcome your feedback. Comments or suggestions can be sent electronically by email to rsdeagle.org. Terms of Use Th
8、e information presented herein is intended solely to assist the reader in the methodologies and/or techniques discussed. These Guidance Notes do not and cannot replace the analysis and/or advice of a qualified professional. It is the responsibility of the reader to perform their own assessment and o
9、btain professional advice. Information contained herein is considered to be pertinent at the time of publication, but may be invalidated as a result of subsequent legislations, regulations, standards, methods, and/or more updated information and the reader assumes full responsibility for compliance.
10、 This publication may not be copied or redistributed in part or in whole without prior written consent from ABS. ii ABSGUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS .2017 Table of Contents GUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS CONTENTS SECTION 1 Introduction 1 1 Overview . 1 3 Description of
11、 Hybrid Riser Systems 1 3.1 General 1 3.3 Hybrid Riser Tower Type (or Hybrid Tower Riser) . 2 3.5 Single Line Hybrid Riser Type . 2 3.7 Other Hybrid Riser Types 4 5 Applicability . 4 7 Alternatives . 4 7.1 General 4 7.3 National Standards 4 9 Definitions and Abbreviations . 4 9.1 Definitions 4 9.3 A
12、bbreviations . 6 FIGURE 1 Illustration of an SLHR 3 SECTION 2 System Design . 9 1 General . 9 3 Design Flowchart 9 5 Design Basis Data 10 7 System Design 11 7.1 System Requirements . 11 7.3 Global Configuration 11 9 Components Design . 12 9.1 General 12 9.3 Riser String 12 9.5 Top Flexible Jumper 13
13、 9.7 Buoyancy Tank 14 9.9 Top Riser Assembly 15 9.11 Bottom Riser Assembly . 15 9.13 Foundation Pile . 16 9.15 Riser Base Jumper 16 9.17 Connectors 16 11 Design Criteria 17 13 Flow Assurance 18 ABSGUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS .2017 iii 15 Material Selection . 18 15.1 General Conside
14、rations . 18 15.3 Specifications 18 17 Coating and Corrosion Control . 19 17.1 Thermal Insulation Coating 19 17.3 Corrosion Coating 19 17.5 Corrosion Protection 19 19 Applicable Codes and Standards . 20 21 Documentation 21 21.1 General 21 21.3 Plans and Specifications 21 21.5 Information Memorandum
15、21 21.7 In-Place Design Engineering Documents 22 21.9 Fabrication Documents 24 21.11 Installation Engineering Documents 24 21.13 Operation, Maintenance and Repair Documents . 25 21.15 As-built Documents 25 TABLE 1 Material Specification Standards 18 TABLE 2 Design Codes, Standards and Specifications
16、 . 20 FIGURE 1 Suggested Hybrid Riser Design Flowchart . 9 SECTION 3 Local Design . 26 1 Buoyancy Tank . 26 1.1 General Principles . 26 1.3 Design Considerations . 26 3 Riser Foundation Pile 27 3.1 Driven Pile . 27 3.3 Suction Pile 27 5 Top Riser Assembly (TRA) . 29 5.1 Design . 29 7 Bottom Riser As
17、sembly (BRA) 30 7.1 Design . 30 SECTION 4 System Global Analysis . 31 1 General . 31 1.1 Analysis Tools . 31 1.3 Loads and Load Case Matrix . 31 1.5 Rationale of Riser Selection for Analysis . 33 3 Global Strength Analysis . 33 3.1 Analysis . 33 3.3 Analysis Procedure 34 3.5 Sensitivity Analyses . 3
18、4 iv ABSGUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS .2017 5 Global Fatigue Analysis 35 5.1 General 35 5.3 Global Motion Fatigue Analysis and Procedure . 35 5.5 Global Vortex Induced Vibration (VIV) Fatigue Analysis and Procedure 36 5.7 Buoyancy Tank (BT) Vortex Induced Motion (VIM) Fatigue Analysi
19、s and Procedure. 38 5.9 Riser Base Jumper (RBJ) Fatigue Analysis and Procedure 39 5.11 Fatigue Analyses in Sour Service Environment . 40 7 Interference Analysis 41 7.1 General 41 7.3 Load Cases . 41 7.5 Minimum Separation . 41 7.7 Interference Analysis Approach . 42 7.9 Interference Analysis Procedu
20、re . 42 7.11 Sensitivity Study 44 9 Analysis Modeling . 44 9.1 General 44 9.3 Floater Motion . 44 9.5 Riser Pipe 44 9.7 Flexible Jumper . 44 9.9 Buoyancy Tank 45 9.11 Foundation Pile . 45 9.13 Buoyancy Tank-Riser Connection . 45 9.15 Top Riser Assembly 45 9.17 Bottom Riser Assembly . 45 9.19 Use of
21、Corrosion Allowance 45 TABLE 1 An (incomplete) Example of Code Mapping . 32 FIGURE 1 Vessel Position Definition . 32 FIGURE 2 Hybrid Riser VIV Fatigue Analysis Flowchart . 37 FIGURE 3 BT VIM Fatigue Analysis Flowchart 39 FIGURE 4 Minimum Separation Definition . 42 FIGURE 5 Interference Analysis Flow
22、chart 43 SECTION 5 Analysis of Components . 46 1 Buoyancy Tank . 46 1.1 General 46 1.3 Load Cases for Buoyancy Tank (BT) Analysis 46 1.5 Buoyancy Tank Strength Analysis and Procedure 47 1.7 Buoyancy Tank Fatigue Analysis and Procedure 49 3 Riser Foundation Pile 52 3.1 Driven Pile . 52 3.3 Suction Pi
23、le . 52 ABSGUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS .2017 v 5 Other Components 56 5.1 General 56 5.3 Structural Components Analysis 57 TABLE 1 Summary of Load Case Matrix for BT Analyses . 46 TABLE 2 Minimum FOS for Pile Capacity 53 TABLE 3 Suction Pile Safety Criteria . 55 TABLE 4 Design Facto
24、rs i55 FIGURE 1 In-Place Loading Condition for BT Strength Analysis . 48 FIGURE 2 In-Place Model for BT Fatigue Analysis 50 FIGURE 3 Design and Analysis Procedure for General Hybrid Riser Structure Components 57 FIGURE 4 Strength Analysis Procedure for Type B Structure . 59 SECTION 6 Fabrication and
25、 Installation . 61 1 Fabrication 61 1.1 General 61 1.3 Quality Requirements 61 1.5 Qualification Requirements 62 1.7 Documentation 62 3 Installation . 63 3.1 General 63 3.3 Installation Methods . 63 3.5 Installation Analysis . 63 5 Post-Installation Survey 63 SECTION 7 Monitoring, Inspection, Mainte
26、nance and Repair 65 1 Monitoring . 65 1.1 Instrumentation 65 1.3 Data Collection 66 1.5 Automation 66 1.7 Remote Monitoring 66 3 Inspection and Maintenance . 66 5 Repair 67 5.1 Flexible Jumper Replacement . 67 5.3 Tether Replacement 67 5.5 RBJ Replacement 67 7 Related ABS Documents 67 TABLE 1 Typica
27、l Instruments for Monitoring In-service Risers 65 SECTION 8 Decommissioning . 68 APPENDIX 1 References 69 vi ABSGUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS .2017 APPENDIX 2 Design and Analysis Example 72 1 General . 72 3 General Design Data and Tolerance 72 3.1 Floater Data . 74 3.3 Riser System D
28、ata 74 3.5 Riser Components Data 75 3.7 Environmental Data . 77 3.9 Hydrodynamic Coefficients 77 3.11 Mooring System Data 78 3.13 Tolerances . 78 5 Load Case Matrix 78 7 Burst and Collapse Check 79 7.1 General 79 7.3 Burst Check . 79 7.5 Collapse Resistance Check . 80 7.7 Collapse Propagation Check
29、. 82 7.9 Summary of Vertical Riser Pipe Capacity 82 9 Combined Load Check . 83 9.1 API STD 2RD Combined Loads Criteria (Method 1) . 83 TABLE 1 Hybrid Riser General Arrangement Data 74 TABLE 2 Riser Line Pipe Physical Data . 74 TABLE 3 Internal Fluid Properties and Design Pressures . 75 TABLE 4 Flexi
30、ble Jumper Characteristics 75 TABLE 5 Stiffener Characteristics for Flexible Jumper 76 TABLE 6 RBJ Data . 76 TABLE 7 Hydrodynamic Coefficients of Riser Pipe . 77 TABLE 8 Hydrodynamic Coefficients of Buoyancy Tank . 78 TABLE 9 Drag Coefficients of Flexible Jumper 78 TABLE 10 Example SLHR Load Case Ma
31、trix for Global Strength Analysis (GoM) 79 TABLE 11 Internal Overpressure Limits for Vertical Riser . 80 TABLE 12 External Overpressure Limits for Vertical Riser (Method 1) . 81 TABLE 13 External Overpressure Limits for Vertical Riser (Method 2) . 81 TABLE 14 Summary of Vertical Riser Pipe Capacity
32、. 82 TABLE 15 Riser Loads at Bottom of UTSJ 83 FIGURE 1 Example General Arrangement of a Hybrid Riser System . 73 ABSGUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS .2017 vii This Page Intentionally Left Blank Section 1: Introduction SECTION 1 Introduction 1 Overview The principal elements of a subsea
33、 hybrid riser system are a vertical, or catenary, steel riser(s) tensioned by a near subsurface buoyancy tank, and a flexible jumper connecting the riser(s) to a floater. The vertical, or catenary, riser(s) may be anchored to the seabed using a foundation pile or connected to a flowline end terminat
34、ion (FLET) directly. A hybrid riser system may be installed before or after the Floating Production Installation (referred to herein as an FPI, or floater) is moored on site; (e.g., a Floating Production Storage and Offloading (FPSO) installation). The risers own weight is supported by the buoyancy
35、tank, resulting in lower reactions on the floater. The flexible jumper allows the riser to be substantially decoupled from the floaters motions, which makes the riser fatigue response typically insensitive to the floaters motions. A hybrid riser system configuration combines the features of tensione
36、d and compliant risers in an efficient manner. Most proposed designs are based on combining a self-supporting vertical riser column (e.g., by means of a buoyancy tank) with a flexible jumper at the upper end for connection to a floater. However hybrid risers tend to be very complex structural system
37、s with special design challenges for both in-situ conditions as well as during the installation phase. Hybrid riser systems are a field-proven concept; they have been installed in the Gulf of Mexico, offshore Brazil and offshore West Africa. Hybrid riser systems have been installed in water depths r
38、anging from 1,500 ft. to over 8,600 ft. Hybrid riser systems can be associated with any floater type. Typically such systems have been used with floating production installations (FPIs) as this takes advantage of one of the hybrid riser systems best aspects, which is its ability to decouple the rigi
39、d riser system from the FPIs motions. This decoupling can reduce the necessity of using a vessel with enhanced motion-performance. 3 Description of Hybrid Riser Systems 3.1 General Although there are different versions of hybrid riser systems, and their configurations have been modified through the
40、years, the key technical benefit of this concept remains that the major rigid vertical, or catenary, riser is isolated from the FPI using an upper flexible jumper as a connection. The rigid riser is thus substantially decoupled from FPI motion. So far, the hybrid riser system concepts that have been
41、 developed are as follows: Hybrid Riser Tower (HRT) Single Line Hybrid Riser (SLHR) Tension Leg Riser (TLR) Hybrid S Riser System (HySR) Hybrid Catenary Riser (HCR) ABSGUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS .2017 1 Section 1 Introduction 3.3 Hybrid Riser Tower Type (or Hybrid Tower Riser) The
42、 riser tower consists of a center core tubular surrounded by production, water injection, and service lines internal or external to the bundle, either fully enclosed or attached on the periphery of the syntactic foam buoyancy module. The vertical column of the riser tower normally consists of a bund
43、le of steel risers. A buoyancy tank at the top provides the required tension, and syntactic buoyancy units along the length reduce the wet weight and may also provide insulation if riser pipes are enclosed within. The upper end of the vertical column is connected to the FPI by multiple flexible jump
44、ers. The tower type has been used for deepwater fields mainly in West Africa, although the first riser tower was installed in the Gulf of Mexico. All these riser towers were fabricated onshore, towed to sites and upended. A typical HRT consists of the following components: Top Flexible Jumper(s) Buo
45、yancy Tank Top Riser Assembly (TRA including Gooseneck Assembly) Continuous Riser Bundle Section Bottom Riser Assembly (BRA) Bottom Connector (e.g., latch type connector) Riser Tower Anchor Rigid Jumper Spool connection to FLETs 3.5 Single Line Hybrid Riser Type A single line hybrid riser (SLHR) con
46、sists of a vertical rigid pipe anchored to the seabed via a foundation (e.g., suction pile) and tensioned by means of a near-surface buoyancy tank that provides the required uplift force. For the SLHR, one flexible jumper connects the rigid riser via a gooseneck to the FPI. The connection of the ris
47、er to seabed is by means of mechanical connector (e.g., latch type connector or taper joint). A riser base jumper, either flexible or rigid, connects BRA and FLET. A typical SLHR concept is illustrated in Section 1, Figure 1. Such a vertical rigid riser pipe can be installed using either J-lay or Re
48、el-lay. There are several different names of SLHR, for example, single line (or leg) offset riser (SLOR), single top tension riser (STTR), single line free standing hybrid riser (SLFSHR), free standing hybrid riser (FSHR), and single line (or leg) hybrid riser. SLHR broadly includes the pipe in pipe
49、 (PIP) hybrid riser system as well. 2 ABSGUIDANCE NOTES ON SUBSEA HYBRID RISER SYSTEMS .2017 Section 1 Introduction FIGURE 1 Illustration of an SLHR FPSOTurretTop Riser JumperUpper Flexible JointBuoyancy TankTop Riser AssemblyFoundationRiser Base JumperRiser PipeBottom Riser AssemblyLower Flexible JointFlowlineGooseneckA typical SLHR is composed of the following components, as shown in Section 1, Figure 1 above: Top riser jumper (or jumpers for PIP) Umbilical (optional) Top riser jumper connector Buoyancy Tank (BT) Tether Chain/Flexible joint
