A Framework for the Management of Ageing of Safety Critical Elements Offshore

2011 ◽  
Author(s):  
John V. Sharp ◽  
Edmund G. Terry ◽  
John Wintle
Keyword(s):  
Life Extension ◽  
Original Design ◽  
Safety Critical ◽  
Critical Elements ◽  
The North ◽  
Design Life ◽  
Offshore Installations ◽  
Management Processes ◽  
The North Sea ◽  
And Performance

Many offshore installations in the North Sea have now exceeded their original design life and are in a life extension phase. A Framework of six processes has been developed for the management of ageing of Safety Critical Elements (SCEs) in offshore installations. The processes include an analysis of the effect of ageing modes on SCE performance. Examples of performance indicators for typical SCEs are proposed based on how their condition and performance as may be affected by physical deterioration and other effects of ageing. Indicators for calibrating the maturity and effectiveness of the management processes are also suggested.

Life Extension Issues for Ageing Offshore Installations

2008 ◽  
Author(s):  
A. Stacey ◽  
M. Birkinshaw ◽  
J. V. Sharp
Keyword(s):  
Structural Integrity ◽  
Life Extension ◽  
Original Design ◽  
The North ◽  
Design Life ◽  
Offshore Installations ◽  
Need To Evaluate ◽  
Integrity Management ◽  
The North Sea ◽  
The Uk

With many offshore installations in the UK sector of the North Sea now reaching or being in excess of their original anticipated design life, there is a particular need to evaluate approaches to structural integrity management by offshore operators. Ageing processes can affect the structural integrity of the installation and demonstration of adequate performance beyond its original design life is thus a necessary requirement. This paper addresses the issues relevant to the life extension of ageing installations.

Material Issues in Ageing and Life Extension

2011 ◽  
Author(s):  
Erik Ho¨rnlund ◽  
Gerhard Ersdal ◽  
Rolf H. Hinderaker ◽  
Roy Johnsen ◽  
John Sharp
Keyword(s):  
North Sea ◽  
Research Work ◽  
Life Extension ◽  
Material Degradation ◽  
The North ◽  
Design Life ◽  
The North Sea ◽  
Extension Process

A considerable number of the structures in the Norwegian part of the North Sea have passed or are close to their design life. Material degradation will play an important role in the ageing of these structures and the evaluation of their safety. An overview of research work initiated by the Petroleum Safety Authority (PSA) is presented. The paper focuses on various material aspects of ageing related to offshore facilities, the risks they represent to the integrity of a facility and how to deal with them in a life extension process. The paper presents and discusses expectations towards the industry with respect to evaluation of ageing materials in life extension.

scholarly journals A prospective observational study of why people are medically evacuated from offshore installations in the North Sea

BMJ Open ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. e037558
Author(s):  
Anne Waje-Andreassen ◽  
Øyvind Østerås ◽  
Guttorm Brattebø
Keyword(s):  
Observational Study ◽  
North Sea ◽  
Prospective Observational Study ◽  
Oil And Gas ◽  
Record System ◽  
The North ◽  
Transport Services ◽  
Offshore Installations ◽  
Severity Scores ◽  
The North Sea

ObjectivesFew studies have described evacuations due to medical emergencies from the offshore installations in the North Sea, though efficient medical service is essential for the industrial activities in this area. The major oil- and gas-producing companies’ search and rescue (SAR) service is responsible for medical evacuations. Using a prospective approach, we describe the characteristics of patients evacuated by SAR.Design and settingA prospective observational study of the offshore primary care provided by SAR in the North Sea.MethodsPatients were identified by linking flight information from air transport services in 2015/2016 and the company’s medical record system. Standardised forms filled out by SAR nurses during the evacuation were also analysed. In-hospital information was obtained retrospectively from Haukeland University Hospital’s information system.ResultsA total of 381 persons (88% men) were evacuated during the study period. Twenty-seven per cent of missions were due to chest pain and 18% due to trauma. The mean age was 46.0 years. Severity scores were higher for cases due to medical conditions compared with trauma, but the scores were relatively low compared with onshore emergency missions. The busiest months were May, July and December. Weekends were the busiest days.ConclusionThree times as many evacuations from offshore installations are performed due to acute illness than trauma, and cardiac problems are the most common. Although most patients are not severely physiologically deranged, the study documents a need for competent SAR services 24 hours a day year-round. Training and certification should be tailored for the SAR service, as the offshore health service structure and geography differs from the structure onshore.

Integrated Decommissioning of a Pentagon Shaped Production Semisubmersible in the UK: A Unique Challenge

2018 ◽  
Author(s):  
Luis F. Batalla Toro ◽  
Simon L. Reid ◽  
Alfredo Salcines Tudela ◽  
Duncan Graham
Keyword(s):  
Lessons Learned ◽  
Production Unit ◽  
Original Design ◽  
Successful Operation ◽  
Unique Challenge ◽  
The North ◽  
Sequence Of Events ◽  
The North Sea ◽  
Drilling Rigs ◽  
The Uk

Between 1969 and 1977, eleven semisubmersible drilling platforms were designed and built with an innovative pentagon shaped hull, specifically to work in the harsh environment of the North Sea. One of the drilling rigs, the Alexander L. Kielland, was converted soon after construction into an accommodation platform (flotel) and failed catastrophically in 1980. Another, the Pentagon 83 “Drillmaster” (renamed as Buchan Alpha), was being converted to a Floating Production Unit at the time of the disaster. The structure of Buchan Alpha was significantly modified during the conversion of the platform so that it benefited from the lessons learnt following the Alexander L. Kielland accident to ensure that the same sequence of events could not be repeated. This technical paper objective is to explain the integrated decommissioning process of the Buchan Alpha in the UK after more than 40 years since being built and more than 35 years of successful operation since it was converted to a Floating Production Unit, and how the features of its original design have accompanied the platform through the decommissioning process. The scope covers all phases of Buchan Alpha decommissioning from the detailed planning and preparation, the suspension of production up to the dismantling and recycling process. Significant challenges for the decommissioning team included the requirement to preserve the operational status of the subsea infrastructure for potential future field redevelopment and the diver disconnection of the subsea wells. Buchan Alpha’s deep draught presented limitations on the selection of dismantling and recycling yards due to quayside water depths. Complex ballasting operations and removal of the thruster’s propellers were required to facilitate the platform berthing at the quayside. Key lessons learned applicable for future decommissioning of floating production facilities will be shared.

Gas Turbine Intake Filter Systems Related to Offshore Platform Installations

1985 ◽  
Author(s):  
M. H. P. Kimm ◽  
D. Langlands
Keyword(s):  
Gas Turbine ◽  
North Sea ◽  
Specific Reference ◽  
Ideal Condition ◽  
Air Filtration ◽  
Contributing Factors ◽  
The North ◽  
Offshore Installations ◽  
Production Platform ◽  
The North Sea

This Paper covers various aspects with respect to the selection and operation of air filtration associated to offshore gas turbine installations. As the Offshore North Sea industry moves into its second decade, Operators are still trying to improve machine availability and reduce maintenance costs. One of the main contributing factors in their failure to achieve the ideal condition has been poor inlet air filtration caused by bad design and incorrect filter selection. The majority of offshore installations are equipped with filter systems which were originally designed for use on ocean-going vessels. The performance of what has become known as the “High Velocity Salt Eliminator System” has, in most cases, been unsatisfactory, thereby creating a necessity for a continuing search into alternative filter systems. The experiences of most Operators in the North Sea have been very similar, and examination of the platform environment explains why this should be the case. To emphasize the affects of poor air filtration and the savings that can be achieved by the Operator in recognising and correcting the problems, specific reference is made to the experience of Mobil North Sea with the Beryl Alpha Production Platform.

An Oil Field Structural Integrity Assessment for Re-Qualification and Life Extension

2013 ◽  
Author(s):  
Abe Nezamian ◽  
Joshua Altmann
Keyword(s):  
Weight Control ◽  
Structural Integrity ◽  
Offshore Structures ◽  
Oil Field ◽  
Assessment Process ◽  
Performance Criteria ◽  
Life Extension ◽  
Original Design ◽  
Integrity Assessment ◽  
Design Life

The ageing of offshore infrastructure presents a constant and growing challenge for operators. Ageing is characterised by deterioration, change in operational conditions or accidental damages which, in the severe operational environment offshore, can be significant with serious consequences for installation integrity if not managed adequately and efficiently. An oil field consisting of twelve well head platforms, a living quarter platform (XQ), a flare platform (XFP) and a processing platform (XPA) are the focus of this paper, providing an overview of the integrity assessment process. In order to ensure technical and operational integrity of these ageing facilities, the fitness for service of these offshore structures needs to be maintained. Assessments of the structural integrity of thirteen identified platforms under existing conditions were undertaken as these platforms are either nearing the end of their design life or have exceeded more than 50% of their design life. Information on history, characteristic data, condition data and inspection results were collected to assess the current state and to predict the future state of the facility for possible life extension. The information included but was not limited to as built data, brown fields modifications, additional risers and clamp-on conductors and incorporation of subsea and topside inspection findings. In-service integrity assessments, pushover analyses, corrosion control and cathodic protection assessments and weight control reports were completed to evaluate the integrity of these facilities for requalification to 2019 and life extension to 2030. The analytical models and calculations were updated based on the most recent inspection results and weight control reports. A requalification and life extension report was prepared for each platform to outline the performance criteria acceptance to achieve requalification until 2019 and life extension until 2030. This paper documents the methodology to assess the platform structural integrity in order to evaluate platform integrity for the remaining and extended design life. An overview of various aspects of ageing related to these offshore facilities, representing risk to the integrity, the required procedures and re assessment criteria for deciding on life extension of these facilities is presented. This paper also provides an overall view of the structural requirements, justifications and calibrations of the original design for the life extension to maintain the safety level by means of maintenance and inspection programs balancing the ageing mechanisms and improving the reliability of assessment results.

Long-term dynamics of fouling communities found on offshore installations in the North Sea

2003 ◽  
Vol 83 (5) ◽  
pp. 897-901 ◽  
Author(s):  
P. Whomersley ◽  
G.B. Picken
Keyword(s):  
North Sea ◽  
Offshore Platforms ◽  
Fouling Communities ◽  
The North ◽  
Offshore Installations ◽  
Oil Export ◽  
The North Sea ◽  
Northern North Sea ◽  
Fouling Organisms

Inspection videos of four offshore platforms in the central and northern North Sea were used to study the development of fouling communities on clamps and guides of oil export risers over an 11-y period (1989–2000). Results from multivariate analyses (multi-dimensional scaling and analysis of similarities) indicated that distinct assemblages developed in different geographical locations. These differences were mainly due to the protracted development of theMetridium senile(Cnidaria: Actinaria) zone on the northern sector platforms. The vertical zonation of fouling organisms was similar on all installations, although the water depth at platform locations varied from 80 to 169 m, indicating that fouling organisms display a wide bathymetric tolerance. This study has highlighted the value of long-term data present in operational inspection videos for the study of fouling communities.

Offshore Safety Assessment and Safety-Based Decision-Making—The Current Status and Future Aspects

1999 ◽  
Vol 122 (2) ◽  
pp. 93-99 ◽  
Author(s):  
J. Wang ◽  
O. Kieran
Keyword(s):  
Decision Making ◽  
Safety Assessment ◽  
Safety Analysis ◽  
Current Status ◽  
Safety Critical ◽  
Critical Elements ◽  
Offshore Installations ◽  
Safety Case ◽  
The Uk ◽  
Further Development

The offshore installations (safety case) regulations were developed in the UK in 1992 and came into force in 1993 in response to the accepted findings of the Piper Alpha enquiry. Recently, “the offshore installations and wells (design and construction, etc.) regulations” (DCR 1996) were introduced to offshore safety analysis. From the earliest stages of the installation’s life cycle, operators must ensure that all safety-critical elements in both the software and system domains be assessed. Hazards can be identified and the risks associated with them can be assessed and evaluated using a number of techniques and decision-making strategies, all aimed at producing an installation with lifetime safety integrity. In this paper, following a brief review of the current status of offshore safety regulation in the UK, several offshore safety assessment frameworks are presented. These include top-down, bottom-up, probabilistic, and subjective approaches. The conditions under which each approach may be applied effectively and efficiently are discussed. Probabilistic safety-based decision-making and subjective safety-based decision-making are then studied. Two examples are used to demonstrate the decision-making approaches. Recommendations on further development in offshore safety analysis are suggested. [S0892-7219(00)00901-8]

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