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A large part of the Norwegian gas and oil production facilities has reached their initial design life, but the respective fields are still producing substantial levels of hydrocarbons. In order to ensure technical and operational integrity of these ageing facilities the Norwegian oil industry Association (OLF) has initiated a project to establish the necessary standards and guidelines for assessing and ensuring safe life extensions. This paper presents this project and the headlines of these standards and guidelines.
Citation preview
Life Extension of Aging Petroleum Production Facilities Offshore
Per Otto Selnes, M.Sc. Manager OperationsNorwegian Oil Industry Associationwww.olf.no
Contributor:Gerhard Ersdal, Ph.D.Principal EngineerNorwegian Petroleum Safety Authority
Introduction
• A large part of the Norwegian gas and oil production facilities have reached their initial design life, but the respective fields are still producing substantial levels of hydrocarbons.
• In order to ensure technical and operational integrity of these ageing facilities the Norwegian oil industry Association (OLF) has initiated a project to establish the necessary standards and guidelines for assessing and ensuring safe life extensions.
Background
Technical and operational integrity ofoffshore facilities on the NorwegianContinental Shelf (NCS) is importantfor:
• the safety, health and welfare of offshore employees and their families
• not harming the environment
• making sure that the owners get no interruption of their revenues, nor do the government and the citizens of the country
Complex issue
Age vs status on application for consent• Number of installations on the NCS excl. pipelines:
• Number of consents expiring by end 2015:
• Number of new consents given (Incl. 1 expiring 2015):
• Number of applications being prepared / handled:
• Number of applications due?
• Number of installations shut down:
• Removed/disposed of, additional to the 103
• Disposals approved
103
44
26
7
1
2
5
7
Norwegian pipelinesFirst installations (year) 1971
Total number of items in database : 920
Cumulated length of large pipelines (km): 6 100
Large variations in length, size and design life
Lengths: 23 km - 1 200 km
Diameter (inches): 1’’ – 44’’
Design lifetime (years) : 5 - 50
Scope of workWork divided in two:• Firstly to develop and issue recommended
guidelines, outlining a proposal for the preparation of the application of a new consent;
• Then to develop tools necessary to assess continued safe operation. Split in the following areas:
• Risk management • Working environment • Structural integrity • Technical safety systems • Drilling & well systems• Top side process & utility systems • Transport systems (pipelines etc.) • Sub sea systems
Consent Applications for Lifetime Extension of FacilitiesScope of the OLF guideline for assessments and preparation of applications
Offshore Structures
Published May 2008
Transport Systems
Underwater installations
Drilling and Well Systems
Check List Published in May 2008
OLF guidelineNo. 122
Published in June 2008
Permanente structures
Export and intra field Pipelines and risers.
Drilling systems and Well integrity, including conductors, BOP and down hole equipment
Technical Safety Systems,,Working
Environment and Risk management
Emergency Shutdown, Evacuation, Barriers, Fire and Gas Detection and other safety systems. Living Quarters, Escape Ways, Material and Chemicals Handling , Control Rooms, Man machine interfaces.
Process Systems
Consent Applications for Life Extension of Facilities are submitted to the Petroleum Safety Authority (PSA) Norway and Norwegian Petroleum Directorate (NPD).
Main Document
Sub- Documents
Deliveries
Guideline for the assessment and documentation of service life extension of facilities Three chapters• Outlines a proposal for the preparation of the application
of renewed consent required prior to use of a facility exceeding the current consent period
• The guideline identifies how the operators can assess and document safe operation of facilities for an extended period
• Facilitate the preparation the Application for Consent for Life Extension
Start early• It is recommended to start the evaluation and application
process at least two years prior to the expiry of the current consent period
Technical Safety Systems and Working EnvironmentRisk Management• Gives detailed comments and
recommendations for the assessment of facilities concerning the areas outlined
– recommends Quantitative Risk Analysis (QRA) and necessary sensitivity studies to be updated addressing the scenario and operating conditions envisaged during the life extension period
– Evaluations of factors that may be expected to change over time should be included in the sensitivity evaluations.
Technical Integrity• Normally it is possible to safely operate an installation
beyond its calculated fatigue life by using the inspection results available
• For structural details that can not be inspected, recommendations are given in the standard.
• Piles securing the installation to the sea bed are an example of such structural elements
• Specific requirements to design fatigue factors for calculation of fatigue damage from driving are given, based on driving records
Structural Integrity for Existing Offshore Load-Bearing StructuresNew Norsok Standard• NORSOK N-006 standard gives requirements
for assessment of the structural integrity of offshore structures in-service and for life extension
• NORSOK N-006 is applicable to all types of offshore structures used in the petroleum activities, including bottom founded structuresas well as floating structures.
Drilling & Well SystemsChecklist has been established• General considerations and requirements:
– Brief status on drilling facilities & wells
– Main degradation mechanisms and corresponding control measures relating to “Safety Critical Equipment”
– Well integrity situation and potential changes in the related risk-picture
– Potential well stimulation, intervention & work over methods/ limits
– Future activity level and modification plans– Future capabilities required to monitor, access,
operate, maintain and abandon drilling- and well facilitiesCondition of utility systems to support future D&W activities
– Future capabilities to serve for potential “tie-ins” and specific measures for enhanced petroleum recovery in the area
Top Side Process and Utility SystemsA list of systems that should beaddressed during assessing lifeextension of top side’s process andutility systems has been established• Containing “common factors” to be
considered when evaluating the integrity of process and utility systems.
– Have conditions changed from when the system was designed?
– Will future operations still be within the capabilities of the system?
– Could specific studies be required (list typical studies for individual systems)
Transport and sub sea systemsNorsok standards
Transport Systems (Pipelines Etc.)• The transport system in this context is facilitating transport through
pipelines, risers and loading hoses intra-field, inter-field and as trunk pipelines to shore and onshore.
Sub Sea Systems• Subsea systems are increasingly used on
the Norwegian Continental Shelf and this standard is prepared to support the process of assuring technical integrity of the sub sea system and its elements beyond the original approved service life.
ConclusionThe guidelines, standards and checklists developed through this project will provide valuable assistance to offshore facility owners and authorities when assessing the condition of aging facilities, and if they can be safely operated for a new consent period.