Dec 2008 Rev G
|Rev||Date||Details of revision|
|B||24.01.08||Third draft with supporting material in background document|
|C||09.05.08||Finalisation containing Operation Manager comments and distribution|
|D||10.06.08||Further finalisation with more Operations Manager comments. Issues for discussion rather than change shown in violet|
|E||18.09.08||Research items identified|
|F||08.10.08||Jack up detail added|
|G||15.12.08||Review by SW - comments|
1 This document sets out the OSD five-year strategy (2008-2013) in relation to the major hazards threat to the safety of offshore installations from loss of structural integrity, and updates the previous version. (A formal OSD structural integrity (SI) strategy has been in place since 2001, and was revised in 2005 and made available publicly on the internet. Although comprehensive, the prioritisation within the original document was limited, and this current prioritised strategy represents a significant revision (see Paragraphs 12 and 13). The nature of the hazards and appropriate barriers, and the frontline activities of OSD (i.e. assessment, inspection, standards making, guidance development and associated research) are fundamental to the SI strategy and so the focus, objectives and interventions to achieve the desired outcomes remain unchanged.)
2 The aim of this strategy is to secure the life-cycle structural integrity of offshore installations in order to safeguard those working offshore. It forms an integral part of the Major Hazards Strategic Programme within which the generic aim is "To reduce still further the likelihood of catastrophic accidents in key major hazards industries". To this end, key themes for the offshore industry are:
all of which are essential elements for managing structural integrity and are reflected in this strategy document.
3 The strategy is presented in the context of the operating conditions for offshore oil & gas installations (Background) and prioritisation of current issues. It explains the measures to be deployed and their rationale (Intervention Strategy), identifies the parties involved (Stakeholder Engagement) and recognises key issues which remain to be addressed (Future Challenges). The Offshore Installations (Safety Case) Regulations 2005 provide supporting detail.
4 Structural integrity of offshore structures (floating, fixed and jack up installations) is the responsibility of OSD4.1 and OSD4.2 (OSD structural integrity specialists also, from time to time, get involved in other structural integrity work in support of other non hydrocarbon related offshore installations e.g. windfarms, docks and locks), which act as the focal point for the Division. The main aspects of structural integrity which form the majority of the work are (using hazard based notation):
5 This current structural integrity strategy covers the following technical areas (TA) which have been prioritised from the above aspects. The TAs are numbered for convenience and the numbering does not reflect their relative importance:
6 Structural failure could cause the immediate total loss of an installation, with little chance of personnel surviving. Reliability studies suggest that failure frequency could be as high as 10-3 per annum. Failure could arise through:
7 Structural integrity management is the principal barrier to safeguard those working offshore from these risks. The integrity of offshore structures depend upon getting it right at the design and construction stage, and keeping it right in service, and these requirements form the basis of the integrity provisions of the Offshore Installations and Wells (Design and Construction, etc) Regulations2 (DCR).
8 Influences on offshore structural integrity practice include:
9 The OSD structural integrity strategy is delivered by balanced intervention at different levels This ranges from direct contact in relation to individual installations or dutyholders, through concerted action with industry on specific themes, to wider engagement with industry representatives and intermediaries on generic technical matters. For any given area, multiple complementary interventions are required. Specific interventions and their contribution include:
10 Although the original OSD structural integrity strategy was not prioritised, progress in delivering the strategy has been subject to thorough and ongoing review with annual operating plans successively prioritising action in critical risk areas3. Analysis of key risk areas and strategic concerns arising from safety case assessment (SCA), enforcement and intelligence through the intervening period have added to the review process.
11 The strategy in this document follows on from the review focusing, in particular, on high risk elements of the original strategy which are of continuing concern and drawing in emerging technical issues from incident and accident investigations which have underlined their importance and need for prioritisation. Attention to asset integrity, competence, safety culture, and leadership forms an integral part.
12 OSD interventions with offshore dutyholders to tackle the current structural integrity technical areas (see paragraph 5) are summarised below. Each area is addressed with a complex mix of interventions (safety case assessment, themed inspections, standards work, and internal documentation research). Some interventions run in parallel; all are required to give a solid basis for securing lifecycle structural integrity.
This is our primary strategic intervention, building individual dutyholder and installation inspections together on intelligence from Safety Case assessments. Examination of facilities condition offshore, where appropriate, combines with scrutiny of structural integrity management systems (whether in relation to topside fabric maintenance and structural integrity, underwater structural integrity, or specific floating / mobile installations structural integrity concerns) onshore. All these areas have a suite of programme documentation including a review of recent research, a list of prioritised installations, and an inspection proforma. The specific approaches are as follows:
Inspections on topside fabric maintenance and structural integrity are undertaken both onshore and offshore with installations chosen based on age and staffing level. The topside structural integrity management system (if documented) is examined within the safety case prior to the inspection. The research for this was completed in 2005 and internal guidance produced as part of the inspection documentation. Future work includes completion of inspections, analysis of findings and production of future plans for this aspect, although this particular area is taking a low priority until after the completion of the OSD Corrosion Management Project in 2010.
Inspections on underwater structural integrity are performed at dutyholder offices onshore with all fixed unattended installation dutyholders being inspected. Safety cases for the installations give a general view of the dutyholder’s underwater structural integrity management process. The aim of the subsequent inspection is to: validate the relevant information in the safety case; ascertain the stakeholders involved in the underwater inspection process; ascertain the major means of inspection and the dates of next inspection; and, for older installations, the preparedness and process for reassessment of the installation. OSD has currently commissioned research into tools for structural reassessment, efficacy of inspection methods, and management frameworks for ensuring appropriate activities associated with ageing are undertaken. The results of this work will be incorporated into future inspections relating to the management of structural integrity for ageing offshore structures from 2009/10 onwards.
Inspections on floating installations are performed both onshore and offshore. The installations are chosen by the date of the last inspection with the overall aim of probing the inspection processes, especially seeking information on the next major inshore inspection
From 2009/10 onwards, the priority issue for structural integrity interventions for floating structure dutyholders will be to assess how they are managing the structural integrity of their ageing installations.
Inspections of mobile jackup installations are performed both onshore and offshore. Onshore the inspections focus on the dutyholder’s generic integrity management and verification (including Classification) arrangements and the survey / inspection results on an individual installation basis. Offshore inspections concentrate on the physical condition of primary and secondary structure including jackhouses and leg / hull connections. Offshore inspections also examine the management of deck loading and centre of gravity monitoring. Prioritisation is largely by installation age, but additionally with more focus on brand new jackups and jackups moving into UK waters from outside NW Europe.
These themed inspections are all driving towards a generic approach to structural integrity management. We will also use our technical policy on the specific topic of management of deterioration to provide a parallel intervention mechanism to communicate expectations across the industry, complementing the installation / dutyholder specific interventions. Standards work, research and internal documents consolidating experience and good practice form an integral part of this aspect of the strategy.
The primary intervention in relation to dynamic response and the effects on the integrity of the structure have been through follow-up inspection in light of incidents (e.g. boat impacts). With increasing combined operations activity, the focus is turning to a more proactive approach, assimilating the experience from incidents and intelligence from the inspections. A technical policy (currently under development) will form the baseline for planned installation-related inspections and inspection requirements of combined operations notifications through a new themed inspection activity from 2009/10 onwards, assimilating safety case information and its translation into specific measures offshore.
The interventions planned for 2008/09 reflect the inherent challenge of the un-observable nature of incipient foundation failure. A technical policy has been developed (drawing on recent investigations and failures, and research on the adequacy of new industry standards) against which a targeted inspection programme will be devised. This will combine onshore and offshore elements, in accordance with the existing successful theme inspection model, in relation to structural integrity management, its communication and practice. The priority will be jack-up dutyholders, with the interventions including assessment against HSE Offshore Information Sheet 3/2008/4 (site specific soils investigations) and HSE Offshore Information Sheet 4/2007/5 (rack phase difference).
The demand for intervention for floating / mobile installations is determined, in part, by the vessels entering UK waters and recent incidents associated with, what to date have been, ‘non-standard’ materials in the sector and effects of their ageing on structural integrity. The strategy is to utilise the full range of interventions to gather intelligence from Safety Case assessment and inspection and through research, to develop the understanding to inform internal guidance on which targeted inspection can build. In parallel, standards work on the range of relevant materials will help accelerate improved industry practices.
Reliability as a statistical concept is associated with the notion of dependability and survival of offshore installations in the face of structural integrity threats. Reliability is determined using quantitative measures of failure which can be complex and opaque and the priority is to develop internal guidance on the appropriate use of reliability techniques. Dependability may also be couched in terms of performance standards providing a common currency for verification and inspection. For structural integrity, performance standards and verification activity in general have focused on survival criteria with insufficient attention given to fitness for purpose or other limiting criteria for safe continued operation. Internal guidance in the form of a technical policy is planned and will equip inspectors to pursue this important issue effectively whenever it is proposed by dutyholders in future inspection adding to the technology for evaluating extended life matters.
Following major inspection activity through 2007/8 associated with the technical policy, a lower level of activity is planned in 2008/9. The themed inspections with key dutyholders aimed at ensuring the inputs and outputs on extreme hazard control were current and also provided the opportunity to disseminate important data changes and standardisation issues in the metocean area. Dissemination of the research through internal documents and industry standards will continue with Safety Case assessment and inspection activity being subsumed within the underwater activity. From 2009/10 onwards, though, it is intended to focus interventions in this area towards assessing the adequacy of dutyholder metocean advice, following the publication of Offshore Information Sheet 1/20086 (The Role of the Metocean Adviser). In addition, for jack ups the evaluation and provision of an adequate air gap continues to be a focus for inspection.
Intervention activity centres on collaborative work with internal stakeholders (OSD3 topic specialists for topsides issues) to ensure a coherent and holistic approach to this fire and explosion threat to structural integrity. This will build on the findings from explosion and fire response themed inspections on and offshore undertaken through 2007/8. These inspections were performed for installations selected from the OSD3 list prioritised in relation to leak frequency and may in future be based on findings from earlier themed dutyholder inspections. A technical policy is under development, which may lead to further targeted intervention
13 Each of the above TAs follows a cycle which involves the following categories:
Each TA may have a different balance of activity in these categories
14 Supporting information about themed inspection activities planned by dutyholder and installation are included in Appendix A. This shows progress to date on this themed inspection approach. These current plans are set in the context of progress with themed structural integrity inspections across the industry to date.
15 Although OSD’s primary route for engagement on structural integrity issues is at an individual dutyholder basis, there are a wide number of other relevant stakeholders which we need to influence on structural integrity matters, including technical and standards making bodies, other industry bodies and fora, fellow Regulators, and the offshore workforce.
16 OSD is committed to influencing the development of the suite of ISO Standards which relate to offshore structural integrity issues, to ensure that the experience of the UK offshore environment is taken into account, and that the standards themselves provide an adequate level of structural integrity provisions which will not compromise safety or our current offshore legislative regime. In general, OSD will be able to adequately influence the ISO standards making process at correspondence level and by briefing UK industry representatives, but where significant changes are proposed then more direct involvement may be appropriate, as is currently the case for ISO 19905-1 (Site specific assessment of mobile offshore units – Part 1: Jack-Ups). This is one of the suites of offshore structures related ISO standards that are being developed by workgroup WG7 under ISO TC67/SC7. The full list of OSD’s involvement in ISO standards is given in Appendix B.
17 There are also a number of other specific structural integrity topic specific forums which OSD will attend in order to influence discussion and add safety perspectives. OSD will therefore play an active role in the following, in particular to drive output with appropriate safety perspectives:
Actual involvement varies but is usually attendance at quarterly meetings at which committee business and technical presentations are given and discussed.
18 Engagement at an international Regulatory level continues to provide an effective exchange of information and concerns and will continue to be supported. In particular there is opportunity to discuss important OSD priorities, mainly in areas of ageing and extreme weather hazards - TA1 and TA6. Engagement takes place on an annual basis or international conference level but is not a regular occurrence as yet.
19 There has been a significant decline in wider stakeholder engagement on structural integrity issues since the late ’90s with UKOOA (now Oil & Gas UK) withdrawing its Technical Committee structure. Some ad hoc activity remains but this does not engage the industry fully on structural integrity such that this is an area needing significant improvement. For jack ups the SNAME North Sea Annex meetings that are held every 6 months share information about recent jackup problems encountered on a worldwide basis.
20 At present, other attempts at engagement are on generic and specific matters, for example:
21 Maintaining the structural integrity of the UK fleet of ageing offshore installations, as reserves decline and the nature of companies in the market changes, presents significant challenges for the Regulator whose own staff and specialist expertise come largely from the boom times of the 1980s drawing on significant technical careers covering the full range of existing offshore infrastructure. The consequence is an ambitious work programme within which maintaining and building competence, both internally and externally, are vital.
22 The ageing profile of the specialist workforce within the industry also presents particular challenges for the next five years such that action is needed to ensure the competence that exists is captured and cascaded on to a new competent generation of engineers with expertise and authority. Internally, the ageing profile of HSE’s offshore structural integrity specialists presents similar challenges. To facilitate and capture current knowledge a series of OSD Technical Policies on major matters, especially on structural integrity management and ageing / deterioration, are required.
23 The above challenges can be encapsulated in terms of the ageing infrastructure and an ageing workforce, which are issues of concern for many areas of safety offshore not just structural integrity. Research is required with HSE and industry stakeholders working collaboratively to determine the potential impacts of ageing and the mitigations each can put in place to maintain adequate levels of safety.
24 Within industry it is essential that the safety culture recognises and respects the barrier to the catastrophic loss of integrity that the standards, risk-based management systems and technical specialists provide; and that leadership is needed to ensure suitable and sufficient resources are deployed. With each year the potential for age-related damage and deterioration increases. The inherent challenge thereby increases, underlining the significance of the structural integrity strategy in securing a foothold for HSE to ensure dutyholder management adopts appropriate measures to extend life in a safe and effective fashion.
25 Definition of structural performance standards to date has generally been limited to survival criteria but, as with verification, has not adequately addressed fitness for purpose or limiting performance for continued operations. Research leading to the development of a clear HSE technical policy, and its dissemination is required.
26 These challenges reflect the fundamental need for the barrier approach to major hazards to be accentuated, including emphasis on the role of human and organisational and hardware barriers in controlling threats to structural integrity or enabling safe life extension. Research is needed to determine: (i) how best this understanding can be communicated to structural integrity practitioners, and (ii) how an integrated approach addressing hardware and human factors issues holistically can be developed and embedded in structural integrity practice. For certain types of offshore structure human factors are important in day to day operations (e.g. for jack ups: the human and procedural barriers; jacking; and preloading operations).
27 Over-arching all the above, is a need to forge a path in partnership with industry as leadership on structural integrity matters is assumed and becomes embedded in the safety culture. The need for a forum to act as a repository and developer of good practice and for discussion of emerging issues has been identified but there is a challenge for HSE to support, in collaboration with industry, the initiative so there is effective stakeholder engagement and sustainable leadership. Priming research is needed, however, to look at the lessons from the past and opportunities going forward utilising UK and international links.
28 The jack ups being used in the construction and maintenance activities in the offshore wind farm industry have generally not been specifically designed for the application and the operators often have very limited experience of operating their jack ups in an offshore wind and wave climate. There have been a number of significant incidents, one of which was associated with loss of structural / foundation integrity that could have resulted in multiple fatalities. There is an identified need to work with the industry to improve standards and to produce their own guidance, which OSD will continue to be involved in. The need for proactive inspection is an issue that HSE must decide upon – future intervention activity depends upon this decision.
29 This structural integrity strategy is tackling challenging issues of asset integrity facing the industry in the next five years. Some aspects are characterised by a lack of knowledge and research is vital for enabling strategy delivery. This Section crystallizes the research needs emanating from the strategy.
30 Research in structural integrity can be divided into the seven technical areas (see para 5) and three newer areas identified as future challenges (TA8 – TA10):
31 For any given technical area, multiple complementary interventions are required. Research is needed to keep interventions alive and focused. Research required for this strategy together with current research projects are listed in Appendix C.
32 The demand for research varies as technical understanding matures and/or offshore operational practices change. Research trends in relation to the current strategy priorities are as follows:
33 TA1 Ageing Installations / Structural Integrity Management Topsides deck structures. Future work includes the analysis of findings from interventions and the production of future plans for this aspect.
Underwater Integrity (fixed installations) and integrity of floating / mobile structures
Research is required on: tools for reassessment; efficacy of inspection methods; structural integrity management frameworks for ensuring appropriate activities associated with ageing are undertaken; analysis of outcomes from inspections resulting in sharing information with the industry. A Technical Policy on the specific topic of management of deterioration provides a parallel intervention mechanism through which to communicate expectations across the industry, complementing specific installation / dutyholder interventions. This is supported by research consolidating experience and good practice.
34 TA2 Dynamic Loading & Response. Research is required on the risk to safety critical elements (SCEs) from dynamic loads and response of safety barriers to cement the Technical Policy.
35 TA3 Foundation Failure. Research on foundation failure in offshore structures (including jack-ups) needs to address both failure and the adequacy of new industry standards.
36 TA4 Materials Technology. The demand for intervention is determined, in part, by vessels entering UK waters and recent incidents associated with ‘non-standard’ materials for the sector and the effects of their ageing on structural integrity. The strategy is to gather intelligence from enforcement activities (i.e. safety case assessment and inspection) and through research, to develop the understanding to inform internal guidance on which targeted interventions can be carried out.
37 TA7 Fire and Explosion Response. Research in this area is related to development and production of the technical policy based on an earlier internal Permanent Background Note on the matter.
38 TA8 Ageing Workforce and Competence. The ageing profile of the specialist workforce within the industry presents particular challenges for the foreseeable future and action is needed to ensure the existing competence and knowledge are captured and cascaded to provide a new generation of competent engineers with the appropriate expertise and authority. Technical policies on major matters, especially on structural integrity management and ageing / deterioration, are required to capture the good practice of today based on the intelligence gathered by OSD Inspectors.
39 TA9 Barriers. The barrier approach to major hazards needs to be accentuated, including emphasis on the role of human and organisational and hardware barriers in controlling threats to structural integrity or enabling safe life extension (there is a necessary overlap with above). Research is needed to determine: (a) how best this barrier to understanding can be communicated to structural integrity practitioners, and (b) how an integrated approach addressing hardware and human factors issues holistically can be developed and embedded in structural integrity practice.
40 TA10 Structural Integrity Leadership Forum. Over-arching all the above is a need to forge a path in partnership with industry as leadership on structural integrity matters is assumed and becomes embedded in the safety culture. The need for a forum to act as a repository and developer of good practice and for discussion of emerging issues has been identified but there is a challenge for HSE to support and collaborate with stakeholders, in initiatives in this area so there is effective stakeholder engagement and sustainable leadership. Priming research is needed, however, to look at the lessons from the past and opportunities going forward.
Themed inspection interventions are planned by dutyholder and installation name. They are prioritised according to three aspects:
Progress to date on this themed inspection approach (to March 08) is also given.
The information provided by these inspections about this theme has been sufficient for closure of inspection matters raised by safety case assessment. The Technical Policy, documentation, question sets etc for this theme are yet to be developed.
The information provided by these inspections about this theme has been sufficient for post assessment inspection topic (PAIT) closure. The technical policy, documentation, question sets etc for this theme are yet to be developed.
CD - Committee draft (there can be many versions of these – represents efforts of technical drafting committee)
DIS - draft international standard (represents efforts of editing committee and is usually first international comment stage)
FDIS - final draft international standard (only typos etc after this stage)
19900 General Requirements Review started 2008
19901-1 Metocean - DIS Sept 03 FDIS Jul 05 ISO pub Nov 05 Revision in progress
19901-2 Seismic - DIS Apr 03 FDIS Jul 04 ISO pub Dec 04 Review 2009
19901-3 Topsides - CD Mar 02 DIS July 07 FDIS Aug 08 ISO pub Dec 08
19901-4 Foundations - FDIS Mar 03 ISO pub Aug 03 Revision in progress
19902 Fixed Steel - DIS Sept 04 FDIS July 07 ISO pub Sept 07
19903 Fixed Concrete - CD Oct 02 DIS Oct 04 FDIS Aug 06 ISO pub Dec 06
19901-7 Station Keeping - DIS Mar 04 FDIS Aug 05 ISO pub Dec 05
19901-7 (Amd 1- ISO/CS suggests minor amendment / revision process - schedule) - CD Jan 08 FDIS Apr 08 ISO pub Aug 08
19904-1 Floating MSS - DIS Nov 04 FDIS June 06 ISO pub Oct 06
19904-2 (New part to cover TLPs - Schedule to be determined)
19901-5 Weight Engineering - FDIS Apr 03 ISO pub July 03 Review started 2008
19905-1/2 Jack Ups - CD May 05 DIS Nov 08 FDIS Jan 10 ISO pub May 2010
19906 Arctic - CD Nov 07 DIS Oct 08 FDIS Dec 09 ISO pub Apr 2010 pre FDIS Sept 07
19901-6 Marine Operations - CD Apr 05 DIS Apr 06 FDIS April 08 ISO pub Aug 08
For each Standard there is a number of Work Groups (WG) dealing with specific technical areas.
|1||Evaluation of Worldwide Practices on the Structural Integrity Management and Regulation of Ageing Installations||To review worldwide approaches to the structural integrity management of ageing installations|
|1||Structural Integrity Management Framework for Mobile Installations||To develop a structural integrity management framework for mobile installations|
|1||Further Study of Fatigue Damage to Girth Welds From Low Stresses in the Loading Spectrum (JIP)||To evaluate the fatigue performance of offshore installations under high cycle / low stress fatigue conditions – a source of significant uncertainty in the prediction of the long-term structural integrity of offshore installations – with a view to developing the ISO standard on fatigue assessment|
|1||Investigation of Residual Stresses in Welded Joints (JIP)||To investigate the influence of residual stresses on the structural integrity performance of offshore installations|
|1||Out of plane bending fatigue in mooring chain (JIP)||To investigate the causes of FPSO mooring chain failures|
|1||Updating of offshore accident and incident databases (JIP)||To undertake a further bi-annual update of HSE’s accident and incident database for fixed and floating installations|
|3||Completeness check and Benchmarking of ISO 19905-1 (JIP)||To ensure sufficient levels of safety for jack-up site specific assessments.|
|3||Improved Guidelines for the prediction of geotechnical performance of spud can foundations during installation and removal of jack-up units||This JIP will investigate the impacts of extreme weather conditions (wind, wave and current) on the maritime integrity of floating platforms leading ultimately to the development of a new design methodology. It builds on the work and uncertainties in an earlier HSE Research Report (RR 357 Title 'Expert panel report concerning the survivability of FPSOs in extreme environmental conditions'|
|4||Review and Assessment of Material Property Requirements for Mobile Installations||To review and assess the adequacy of the material property requirements in codes, standards and classification society rules for mobile installations|
|7||Preparation of a Technical Appendix to the Technical Policy Document on structural responses to fires and explosions||To review the OSD Technical Policy Document (TPD) to produce an appendix to identify best practice and gaps in knowledge for the structural design, re-assessment and risk assessment/CBA of topsides structures and equipment to resist fire and explosion loads.|