18-434

Risk Assessment Data Directory

Report No. 434 – 18March 2010

I n t e r n a t i o n a l A s s o c i a t i o n o f O i l & G a s P r o d u c e r s

Construction risk for

offshore units

Publications

Global experience

The International Association of Oil & Gas Producers has access to a wealth of technical knowledge and experience with its members operating around the world in many different terrains. We collate and distil this valuable knowledge for the industry to use as guidelines for good practice by individual members.

Consistent high quality database and guidelines

Our overall aim is to ensure a consistent approach to training, management and best prac-tice throughout the world.

The oil and gas exploration and production industry recognises the need to develop consist-ent databases and records in certain fields. The OGP’s members are encouraged to use the guidelines as a starting point for their operations or to supplement their own policies and regulations which may apply locally.

Internationally recognised source of industry information

Many of our guidelines have been recognised and used by international authorities and safety and environmental bodies. Requests come from governments and non-government organisations around the world as well as from non-member companies.

DisclaimerWhilst every effort has been made to ensure the accuracy of the information contained in this publication, neither the OGP nor any of its members past present or future warrants its accuracy or will, regardless of its or their negligence, assume liability for any foreseeable or unforeseeable use made thereof, which liability is hereby excluded. Consequently, such use is at the recipient’s own risk on the basis that any use by the recipient constitutes agreement to the terms of this disclaimer. The recipient is obliged to inform any subsequent recipient of such terms.

This document may provide guidance supplemental to the requirements of local legislation. Nothing herein, however, is intended to replace, amend, supersede or otherwise depart from such requirements. In the event of any conflict or contradiction between the provisions of this document and local legislation, applicable laws shall prevail.

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The contents of these pages are © The International Association of Oil and Gas Producers. Permission is given to reproduce this report in whole or in part provided (i) that the copyright of OGP and (ii) the source are acknowledged. All other rights are reserved.” Any other use requires the prior written permission of the OGP.

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RADD – Construction risk for offshore units

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Contents

1.0 Scope and Application ........................................................... 1 1.1 Scope ............................................................................................................... 1 1.2 Definitions ....................................................................................................... 1 2.0 Summary of Recommended Data ............................................ 3 2.1 Worldwide Construction Failure Risks ......................................................... 3 2.2 North Sea Construction Failure Frequencies............................................... 3 2.3 Fatal Accident Rate (FAR) data ..................................................................... 3 3.0 Guidance on use of data ........................................................ 4 3.1 General validity ............................................................................................... 4 3.2 Contributors to Severe/Significant or Total Loss Incidents ....................... 4 3.3 Uncertainties ................................................................................................... 4 4.0 Review of data sources ......................................................... 5 4.1 Construction Incident frequency................................................................... 5 4.1.1 Historical Frequencies of Incidents.......................................................................... 5 4.1.2 WOAD Accident Reports ........................................................................................... 6 4.2 FAR data ........................................................................................................ 12 4.2.1 OGP FAR Data .......................................................................................................... 12 4.2.2 Comparison with other industries .......................................................................... 13 4.2.3 Construction FAR breakdown by Region .............................................................. 13 4.2.4 Norwegian Construction Data................................................................................. 13 5.0 Recommended data sources for further information ............ 13 6.0 References .......................................................................... 14


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Abbreviations: DPS Dynamic Positioning System E&P Exploration and Production FAR Fatal Accident Rate FPSO Floating Production, Storage and Offloading FSU Floating Storage Unit GoM Gulf of Mexico HSE (UK) Health & Safety Executive MODU Mobile Offshore Drilling Unit MOPU Mobile Offshore Production Unit NPD Norwegian Petroleum Directorate NS North Sea OGP International Association of Oil and Gas Producers OSHA Occupational Safety & Health Administration PSA Petroleum Services Authority (Norway) QRA Quantitative Risk Assessment TLP Tension Leg Platform UK United Kingdom US United States UKCS United Kingdom Continental Shelf WOAD Worldwide Offshore Accident Databank WW Worldwide


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1.0 Scope and Application

1.1 Scope This datasheet presents estimates of fabrication, construction and installation risks in respect of asset damage/loss and personnel safety. The data are mainly applicable to offshore installations although reference is made to onshore construction fatal accident rates. The datasheet has not been designed to assist with the quantification of general project management uncertainties for the purpose of estimating the likelihood of project schedule and cost overruns. This is considered to be a separate subject. Measured in terms of the life-cycle of a project, the fabrication, construction and installation phases have a short duration and can be characterised as: • labour intensive, • involving a large number of one-off tasks, • requiring temporary work arrangements and working environments, • exposing components/structures to non-design loading condition. In terms of the last of these, structures can be designed to withstand extreme loadings when fixed in-situ, such as an offshore installation being designed for a one-hundred year return wave (a storm having an annual probability of occurrence of 10-2). However, their tolerance can be considerably lower during the temporary phases. In addition, ancillary systems such as semi-submersible crane vessels can be in a condition which makes them vulnerable to adverse weather for the period of an operation. In regard to the QRA of an onshore facility there may be no need to treat the three phases as distinct. All hazardous operations could take place at the one site and the phases could overlap in the project schedule. The risks arising from the use of Temporary Living quarters and in particular the potentially high risk associated with vehicle activity are not included in the construction risks outlined. The Land Transport Accident Statistics datasheet provides an indication of potential vehicle risk which may need to be evaluated when considering the total risks associated with a construction project.

1.2 Definitions • Construction (as defined by OGP [4])

Construction comprises all construction and fabrication activities, and also disassembly, removal and disposal (decommissioning) at the end of the facility life. Factory construction of process plant, yard construction of structures, offshore installation, hook-up and commissioning, and removal of redundant process facilities are all examples which are included under construction activities. With this definition, construction may involve the assembly of relatively large sections of an installation. Examples would include: - lifting of modules onto a module support frame (MSF), - mechanical outfitting of a concrete gravity based structure (GBS).


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Fabrication activities need not take place in the same location as the construction activities. Therefore, construction could involve the transport of substantial sections of the installation between sites. The hazards and risks associated with these activities may need to be considered and analysed within the framework of a “total” risk analysis.

• Fabrication (taken as a subset of Construction above) Activities performed in producing significant sub-components, packages, or modules which will be combined during the construction phase.

• Installation (taken as a subset of Construction above) Activities performed to transfer the structure to, and position it at, the designated site. This definition is tailored to offshore developments, where one or more structures are transported and assembled at the site. An onshore facility may have no equivalent activities. For an offshore jacket platform this phase can include the lifting or load-out of the jacket and deck, onto transport barges. Some structures, such as concrete gravity based structures, can be towed without the assistance of a transport barge.

This data sheet can be used in risk assessments oriented to either quantifying risks to personnel or to quantifying risks to asset integrity. The following damage categorisation as extracted from the Worldwide Offshore Accident Databank (WOAD, [1]) is used, as applied to all accident types: • Total Loss: Total loss of the unit including constructive total loss from an

insurance point of view, however the unit may be repaired and put into operation again.

• Severe Damage: Severe damage to one of more modules of the unit: large /medium damage to load bearing structures: major damage to essential equipment.

• Significant Damage : Significant/serious damage to module and local area of the unit: minor damage to the load bearing structures: significant damage to single essential equipment: damage to more essential essential equipment.

• Minor Damage: Minor damage to single essential equipment: damage to more non essential equipment: damage to non load bearing structures.

• Insignificant Damage: Insignificant or no damage: damage to part of essential equipment, damage to towline, thrusters, generators and drives.


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2.0 Summary of Recommended Data

2.1 Worldwide Construction Failure Risks Table 2.1 outlines the Construction damage risks worldwide, where ‘Construction’ is defined as set out in Section 1.2.

Table 2.1 Construction Damage Risks: Worldwide

Risk of all types of damage 6.5 × 10-3 per unit constructed Risk of Severe/Significant damage 3.1 × 10-3 per unit constructed Risk of Total Loss 3.6 × 10-4 per unit constructed

2.2 North Sea Construction Failure Frequencies Table 2.2 outlines the Construction damage risks in the North Sea, where ‘Construction’ is defined as set out in Section 1.2.

Table 2.2 Construction Damage Risks: North Sea

Risk of all types of damage 6.9 × 10-2 per unit constructed Risk of Severe/Significant damage 3.6 × 10-2 per unit constructed Risk of Total Loss 2.0 × 10-3 per unit constructed

The North Sea damage risks are around 10 times higher than the Worldwide data (Section 3.1 explains this).

2.3 Fatal Accident Rate (FAR) data The best available FAR data for fabrication, construction and installation activities are those extracted from OGP’s Safety Performance Indicator reports for 2006 and 2007 ([4],[6]). Based on specific construction activity safety data collected in these years, the following FARs have been calculated: • 2006: 2.63 • 2007: 2.33 The data have not been split to yield any onshore/offshore specific FAR or Company/contractor FAR as applied to many other breakdowns within [4]. The limited 2 year data collection/ analysis period does not allow for 3 or 5 year rolling bases which offer a stronger (less uncertain) measure of the FAR. Note the reader should be aware of the variation in OGP member company reporting from year to year as this can give rise to some uncertainty on the overall values.


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3.0 Guidance on use of data

3.1 General validity The risk values given in Sections 2.1 and 2.2 are applicable to the offshore oil and gas industry worldwide and specifically in the North Sea. However, it is recommended that failure risk data to be used on particular studies are localised to the country where the unit will be deployed as there are variations and trends on the risks calculated, as can be seen comparing the worldwide and NS data (Table 2.1 and Table 2.2). The worldwide data are dominated by the fixed installations in US GoM. These are historically smaller and simpler than North Sea installations and this is likely to be reflected in the risks. Therefore the Worldwide data is considered appropriate to represent the construction risk for simple installations in shallow water. For large integrated installations in deeper water (including those in deeper water in the GoM) the North Sea data are representative of the risks as there is much more material and overall construction activity involved. The risks reflect incidents that have arisen mainly in the ‘under construction’ phase within WOAD, and do not address the reverse construction / decommissioning risks. Note there is a small category of events listed under “scrapping” category within WOAD, most of which relate to idle units having problems, rather than true decommissioning/ deconstruction activity. Conservatively, as there has been no serious deconstruction events noted to date despite such activities occurring, construction phase risks could be applied to deconstruction activities which are becoming more common.

3.2 Contributors to Severe/Significant or Total Loss Incidents The failure risk data presented in section 2.1 and 2.2 relate to the frequency of overall system failures rather than component failures. Failure data at system level are most useful for a “first pass” QRA, with the function of gauging the overall risk level and estimating the relative contribution of specific activities. By review of the actual incident reports detailed in Table 4.3 to Table 4.6 inclusive, the following hazard types are prevalent: • Dropped objects • Mooring failures • Dynamic positioning failures • Floating unit collisions with installations • Ballasting failures • Weather window forecasting failures. A detailed causal analysis of failures when under construction has not been attempted although the raw incident reports will allow users to interpret causes if desired.

3.3 Uncertainties In some cases the exposure data available makes no distinction between unit categories e.g. for Monohull units there is no distinction between FPSO and FSU. The same situation occurs for WOAD exposure data for fixed units. [2] provides a summary of exposure data used to calculate worldwide structural failure accident frequencies.


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Hence, by making no distinction in the exposure data the calculated frequency may be overestimated or underestimated for FSPO, FSU and Fixed units within WOAD.

4.0 Review of data sources

4.1 Construction Incident frequency The principal source of the data presented in Section 2.1 is the data from WOAD for the period 1980-2005 [1] and the HSE [7],[8] for 1980-2005. Databases available worldwide were thoroughly reviewed and interrogated appropriately in producing these sources. It is therefore believed that they are reasonably complete in recording accidents and incidents worldwide and on the NS for offshore units. These statistics are based on the numbers of incidents evident within WOAD software v5.1 and the exposure data (number of unit years) [2],[7],[8]. Accident data used cover the time period from 1980 to 2005 as this is the basis of the exposure data.

4.1.1 Historical Frequencies of Incidents This section gives a historical picture of all incidents, including their severity during the fabrication, construction and installation phases of offshore projects. The review is limited to offshore incidents due to the accessibility of relevant accident/incident records. Incidents from WOAD, satisfying following criteria were used for the analysis: • installation type - concrete, jacket, FPSO/FSU, and TLP • operation mode - under construction Examinations of the records found the majority did not occur in the phases as defined by this data sheet. In WOAD, “construction” can cover temporary work on the platform at any point in its lifecycle. Therefore it was necessary to review each entry to find relevant incidents. It was also found not to be possible to differentiate with confidence between the fabrication or construction phases of a project. Overall estimates of incident/accident frequencies for all phases are given in Table 4.1 along with the assumptions underlying the estimates. The relevant entries from WOAD are listed in Table 4.2 to Table 4.5 in Section 4.1.2. Table 4.2 details a breakdown on the severity of each of the events on a worldwide and North Sea Basis, used to determine the frequency of severe/significant and total failure frequencies outlined in Table 2.1 and Table 2.2.


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Table 4.1 Summary of WOAD search [4]

Fixed units

Number of reported incidents (in WOAD)

Estimated population (units constructed) (1,2)

Estimated risk of incident/unit constructed

WW NS WW NS WW NS Concrete 13 13 n/a 41 n/a 0.32 Jacket 36 17 8201 425 0.004 0.04 FPSO/ FSU 2 2 77 21 0.026 0.095 TLP 3 2 13 3 0.23 0.67 TOTAL 54 34 8291 490 0.0065 0.069

Note 1

Assumption of total fixed installation World wide:

For the period 1970 – 1995, total number of fixed installations 6515 (100% Jacket) For the period 1996 – 2005, total number of fixed installations 1686 (100% Jacket)

There are few concrete installations outside the North Sea (Hibernia, Sakhalin (Lun-A, PA-B, Molipak), at least 3 off Australia), none of which feature in the WOAD search, and as they are less than 1% of the overall population they are excluded as negligible.

Note 2

Assumption of total fixed installation in North Sea:

For the period 1970 – 1995, total number of fixed installations 360 (10% concrete and 90% Jacket) For the period 1996 – 2005, total number of fixed installations 106 (5% concrete and 95% Jacket)

Table 4.2 Incident Severity

Incident Severity Fixed installations No. of

Events

Insignificant/ no

damage Minor Severe Significa

nt Total Loss

Concrete WW 13 6 1 1 4 1 Concrete NS 13 6 1 1 4 1 Jacket WW 36 9 6 10 9 2 Jacket NS 17 3 2 5 7 0 FPSO/ FSU WW 2 2 0 0 0 0 FPSO/FSU NS 2 2 0 0 0 0 TLP WW 3 0 1 1 1 0 TLP NS 2 0 1 0 1 0

4.1.2 WOAD Accident Reports Table 4.3 to Table 4.6 detail the construction incident descriptions for the 4 fixed installation categories within WOAD [1] for the period up to February 2009.


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Table 4.3 Concrete Facility Under Construction Incidents [1]

Accident Date

Unit Name Description

15-May-96 BRENT,211/29,C The new derrick of the platform drilling rig for the Brent C platform was being transported from Bergen in Norway to the UK on Heerema's derrick barge "DB 102" when the derrick struck a bridge causing damage to the upper section of the derrick. The platform rig was returned to Consafe's Burntisland yard for repairs. An investigation into the accident was initiated. The incident was not expected to delay the re-development of the Brent field. A similar accident occurred in August (see accident in Table 4.4 dated 04-Aug-96 to unit in CAPTAIN field).

12-Aug-95 TROLL,31/6 Smoke developed in a firewater pump located in the seawater shaft. No persons were in the shaft at that moment. No further information available.

15-Apr-95 TROLL,31/6,A During installation of scaffolding below the deck, a worker fell overboard and 20 m down into the sea and was quickly recovered. The worker was in shock and taken to hospital.

09-Aug-92 SLEIPNER,15/9,A2 A fire occurred in a 440 V emergency switchboard. The fire will not hamper the completion of the platform. The replacements and repair work should be completed mid September.

14-May-92 SLEIPNER,15/9,A2 The Aker Verdal yard experienced a construction accident during assembly of the platform jacket. The accident occurred during roll-up and lifting of the upper part of the "row 2" jacket frame (weight 700 tons). One of the two lift slings parted and the frame leaned slowly over and stopped at a 45 deg. Angle without hitting "row 1". No injuries or damage.

23-Aug-91 SLEIPNER,15/9,A1 Water intrusion into one of the drillshafts caused the sinking of the 600,000 tons concrete base of Sleipner 'a' platform. 22 workers onboard were evacuated when the water flooding started. 15 mins later the base sank in water 200 m deep. The base was crushed against the sea bottom and destroyed. Investigations have revealed that the concrete base in some places were underdesigned and hence not able to support the exposed loads. Three separate mistakes led to the sinking: 1: design forces in cracked areas were underestimated; 2: reinforcing steel in those areas was incorrectly designed; 3: some joints were not separately designed. The accident may delay startup of the Sleipner field and it would take approx. 12-15 months to build a new gravity base structure. Insurance claims worth 2.3 billion NOK arising from the loss of the platform were settled in October 1993. This sum covers a new base structure, outfitting lost with the original, the cost of temporarily storing the topsides and additional hook-up work. The amount will be covered by insurance companies Vesta (Norway) and Lloyd's of London.

08-Nov-85 GULLFAKS,34/10,A Steel shock absorbers between the 41.000 ton deck and the legs failed and the deck started tilting. The deck was evacuated. The deck was raised 0.02 m during a 10 hour successful jackup operation Nov.11 and the shock absorbers were replaced by steel plates so that weight was evenly distributed on the four legs. Work was then resumed.

04-Nov-85 GULLFAKS,34/10,B The barge 'concem' was offloading cement into the platform Gullfaks C during slipforming when barge capsized and sank (ref accident id. No 8601100). The barge's 10m high construction tower struck platform and containers on barge's deck clipped side of platform base and caused damage to riser supports. Additional damage resulted from power failure which affected slipforming equipment on platform.

27-Aug-84 FRIGG,25/1,TCP2 A gas leak occurred due to a failure of the bolts of the upper isolating valve of the standpipe for LSH on glycol contactor CV2C. Standpipe and isolating valves were removed and nozzles blinded. Cause seems to be that bolts were overstressed due to misaligned supporting and inaccurate tightening of bolts.

25-Feb-78 STATFJORD,33/9A,A During installation of platform four workers were doing welding and grinding at the 49.5 m level of the utility shaft. A liquid surface was 2 m below the workers. Protective coating was added to the water from time to time. Diesel was trapped on top of the surface. Probably due to breakage of acetylene hose a sudden fire ignited the diesel and heavy smoke and fire developed. Air hose to grinding tool was probably melted and escaping air fed the fire. Escape stair tube behaved as a chimney with high flame intensity. 2 men tried to escape by elevator, but this stopped probably due to optical endstop switches activated by heavy smoke. One man was found in the control room, an other at the 49.5 m deck. The only man wearing a breathing apparatus was found at 55.5 m deck with only the last 5 min emergency air left. The smoke divers were forced back at the 61.5 m level due to the strong heat. Water from hoses and deluge system cooled down heat and the fire was under control after about 2 hours.

06-Oct-76 NINIAN NORTH,3/3,CENTRAL

The concrete batching plants barges "no. 3" and "no. 4" and generator barge "h.d. barge no. 3" ranged against fendering of the partly constructed platform. The platform suffered damage to temporary installed anti-scouring fenderings and water ingress. No further info available.


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22-Mar-76 FRIGG,10/1,CPD1 The fire blaze broke out at the base of the towers of the structures about 40 ft from the water level. The fire was extinguished after one hour. About 10 square metres of concrete was damaged into a thickness of one inch.

15-Mar-99 TROLL,31/2,C The incident occurred during pressure testing of the of the Troll C platform structure before connection of deck and hull. Main parts of the hull (including pipe shafts in columns) is filled with water and in order to ensure watertight penetrations for electric-, instrument-, power- and hydraulic cables and pipes "Brattberger connections" are used. The day after the test immersion started, leaks occurred between pipe shaft and pump room in column g 20 and between pipe shaft and stairwell in column g 10. The ballasting operation was stopped immediately and the pump room and the stairwell was de-ballasted, flushed with fresh water and dried out with hot air. Both leaks were caused by leaking "Brattberger connections". The Brattberger connection in the pump room (mct rgsr) was designed for a hydrostatic pressure of 4 bar and started leaking at a water depth of 31.4 m. The supplier (Nortelco) found the cause to be wrong packing of the connection. The Brattberger connection in the stairwell (mct rgpm 100) was design for a hydrostatic pressure of 1.8 bar and started leaking at a waterdepth between 13.2 and 18.2 m. The cause of the leak was that the maximum hydrostatic pressure the connection was designed for had been reached. - it was concluded that an unsuitable connection was installed since this connection will not be capable of handling an unforeseen immersing. Corrective actions taken: all Brattberger connections installed below el. 15.0 m were checked by supplier. All Brattberger connections between pipe shaft and pump room (rgsr) were opened and re-packed. 8 Brattberger connections of type RGPO 100 towards pipe shaft in columns g10 and g20 were replaced with Brattberger connections of type RGPM 100 which are designed for a hydrostatic pressure of 15 bar. All other Brattberger connections of type RGPO was reinforced by use of flat bar welded to both sides of the bulkhead. All work was controlled, checked out and approved by Nortelco AS. When the test immersion was restarted, small leaks from 3 Brattberger connections were discovered. The pipe shafts was de-ballasted and the connections re-packed under control and approval of Nortelco. More information available in archive.

Table 4.4 Steel Jacket Under Construction Incidents [1]

Accident Date


15-Mar-00 VERMILION,267 While derrick barge 'Southern Hercules' was attempting to load the 390-ton vermilion 267 platform deck onto a materials barge in the bayou black channel at the ocean marine facility in Gibson la., the load dropped. The derrick barge's jib broke away from the boom during the lifting operation. The derrick barge suffered minor damage to hull and boom. It was not revealed any damage to deck and no delays to first production was expected. The cause of failure was to be investigated. The accident is also recorded on the derrick barge, see accident id. No. 0004060.

03-Dec-98 PETRONIUS The platform was under construction when a 72 million usd worth 3800-ton south deck module dropped to the seabottom at 2230 hrs as it was being installed onto the deepwater compliant tower platform. The module was being lifted by derrick barge "db 50" when a lifting line parted. The module struck a transport barge being alongside as well as the "db50" before falling to the seafloor in 1754 ft waters. The deck, the second of two modules that were to be pieced together into one unit, held the crew quarters, waterflood facilities and production equipment. It was decided that the module would not be retrieved since it did not pose any threat to the environment or to navigation. In may 1999, the go-ahead for building a new module was given.

17-Jul-98 MAIN PASS,65/B The Nabors offshore drilling platform rig "t-269" was being installed on the 100-ft platform when the rig partially collapsed over the platform (with approx. 70 people onboard) and several sections of the rig fell overboard. However, the largest part of the rig remained intact. The platform was in the final stage of construction when the accident occurred. The rig and heavy drilling set-up were being constructed on top of the platform. When the work was finished there would have been a towering derrick typical of those that drill older fields. Crews were unloading components to the "sub-structure" (supporting the derrick) from a barge to large rails on the platform. Pumping equipment, tanks, electrical components and generator were in place when the accident occurred. The rig split in two sections of which one fell overboard and onto a neighbouring barge. Three workers were killed and 12 persons were injured. Fishing vessels in the area pulled floating workers from the waters and the injured persons were taken to hospital by helicopters and by boats. Two of the dead workers were crushed by the collapse of steel rigging and walkways as the drilling portion of the rig fell.

17-Nov-77 HEATHER,2/5,A In wind NNE 45 knots and 40 feet waves, a 24" pipe, 50ft long, 8 tons, sealed in both ends and floating, broke loose.


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28-Dec-92 BRUCE,9/8A,PUQ Two persons were working on the scaffolding underneath the platform, some 70 ft above the sea, when the scaffolding suddenly collapsed. The incident occurred when they pulled equipment on to the scaffolding. One person fell straight into the icy sea, while the other was trapped by his legs and struggled to free them before he let himself into the sea. Fortunately, none of them suffered injuries apart from shock. Despite not wearing life jackets, both managed to swim to the platform legs within two mins and climb up the ladders before "zodiac" rescue boats were launched and reached the spot.

04-Aug-96 CAPTAIN,13/22A,WPP A During towout of the platform (transport on barge) from the Clydebank yard of UIE Scotland, it collided with the Erskine road bridge (aadt=18000) in the river Clyde, causing damage to the platform's drilling rig and closing of all traffic on the bridge such that engineers assessed the extent of damage. It will probably remain closed to end-august and for heavy vehicles to the end of '96. Reports indicate that the accident may have been caused by a miscalculation of clearances, which failed to take account of the height of the barge being used. Platform repairs were carried out offshore. There may be raised claims by road transport firms to compensate for extra costs due to the closing of the bridge. This was the second such accident within short time, see accident in Table 4.3 dated 15-May-96 to BRENT C.

10-Sep-94 FRÏY,25/5 During cutting of riser pipe, a sheen of oil in the pipe ignited causing a fire. A fire blanket was used to put out the fire. The oil was left in the pipe after flushing during construction.

21-Jan-94 GUNESHLI FIELD PLATFORM The platform capsized and sank during bad weather. The recently installed drilling platform was designed to withstand winds up to 42 m/s. No injuries and no oil was spilled. No decision has been made yet on whether the platform will be salvaged. The platform took over 7 years to build and will cost tens of millions of dollars to replace. No further information available.

27-Oct-93 GRAND ISLE,102 During installation the platform jacket toppled. Certain problems with the jacket's mud mats and inclement weather were encountered during the installation. The jacket is being surveyed for damage. It is expected that the jacket will be salvaged and reinstalled after being repaired at the fabrication yard of "gulf island fabrication" in Houma.

15-Nov-92 BRUCE,9/8A,D During offshore commissioning it was discovered that someone seriously had tampered with electrical cables and pipework in platform's drilling modules. The defects were corrected and the platform's hookup schedule was not affected. The platform is under construction at the Eiffel yard in Marseilles. The Bruce field is scheduled to commence commercial production in spring 1993.

15-Oct-92 GOODWYN A During installation of the platform, the pile foundations (20 off, 130 m long), which should secure the platform to the sea floor, were damaged. After sinking through a soft layer of sand, the piles were supposed to pierce into a thin layer of rock before sinking further into bedrock. However, the piles did not pierce neatly through and were bent and buckled approximately 86 m below the sea bed. A programme aimed at repairing the piles was started immediately so that the topsides installation, hook-up and commissioning could proceed. Initial production is set to October 1994, one year later than expected.

25-Aug-92 BRUCE,9/8A,PUQ A fire occurred on the south-east leg of the platform at 0856 hrs. The fire is believed to have caused by a gas burner pre-heater. Helicopters were scrambled and the platform was downmanned from 34 to 16. M tug/supply vessel "Maersk Rover" (standby vessel for the "beryl a" platform), was put on readiness to assist in fire-fighting if required. Rescue operations terminated at 0930 hrs. The fire was reported put out at 0920 hrs.

13-Jan-92 BRUCE,9/8A,D An explosion occurred to the drilling platform under construction at the Eiffel yard at St Louis du Rhone near Fos (Marseille). The explosion occurred in one of the mud tanks. It is speculated that inflammable gas built up in the tank during the weekend and was ignited when normal construction activities restarted Monday morning. The walls of the module and the scaffolding were hit by the blast. Bp states that the accident will not affect the schedule for the project.

15-Aug-90 OSEBERG 2,30/6,C During piling of the platform, brace no. 7015 was dented. The damage does not affect platform integrity in the period until installation of modules in spring 1991. Corrective actions have been taken.

06-Mar-88 OSEBERG,30/9,B West German submarine U27 collided with the Oseberg B platform. Personnel were evacuated to the hotel platform "Polyconfidence" which is linked to the platform with a gangway. A later survey found that a crossmember with diameter of 1.2 m had been dented to a depth of about 20 cm. The repair costs will probably reach several million dollars. The submarine was navigating approx. 20 m below the surface. The platform was marked on the map, but no signals from the sonar were received. The submarine sustained damage to bow, bridge and navigation equipment. No injuries.

17-May-87 LOGGS GGS,ACCOMODATION One of the newest offshore platforms may have to be cut from the seabed by explosive charges. During piling work severe vibrations caused damage to the jacket. The pile-driving equipment broke down. A substitute pile-driver proved to be too powerful for the piles needed.

14-Jul-86 CHEVRON JACKET UNKNOWN

The platform installed by Brown&Root tipped over while the structure was being set. The incident was believed to be caused by a hole left in the seafloor where the drilling rig had been. The jacket was uprighted and there was no damage.


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26-Jun-86 HARRIET,B The deck structure of Harriet B tilted approx. 20 deg. On barge Intermac 256. Towed to shallow water for safety. The barge's deck received some holes. Salvage required a giant derrick barge and salve cost estimated to 1mill usd. Value of monopod cargo of 350 tonnes is 4mill usd.

07-Jun-86 ZELDA/E Diving/work barge "Satyra Tirta" had accidental contact with the platform. No damage to the platform is reported, but the vessel got its port side shell plating torn open in way of fuel tank and store room associated distortion to internal crop etc. Later inspection showed flooding of winchroom and wetting of electrical cables.

04-Dec-85 PNT ARGUELLO 316,HERMOSA

Jacket contacted lock in panama canal during voyage from Morgan City to Port Hueneme loaded on barge "450-10". One gantry crane needs to be renewed, two turbo generator casings reconditioned and partly renewed, 2 sets of electric conduits and one air winch clutch renewed. Repairs deferred.

09-Jun-82 NORTH RANKIN,A Damage to valve removal track during launching. 01-Apr-82 MAGNUS,211/12,PRODUCTION Installation of the 40000 tonne structure halted because several steel piles fell off the structure altering the balance of the

structure. The piles were needed to secure it to the seabed. The piles were discovered 100 yards clear of the platform target location. The oil platform was finally sited on the Magnus field Apr 4.

25-Feb-82 TYRA,5504/6.2,TE-E Damage to jacket due to storm during tow out. 15-Jul-81 VALHALL,2/8A,PCP During installation of the jacket in July 1981, a pile hammer was accidently dropped on the east side of the jacket. An investigation

survey by use of ROV showed no damage to jacket structure. During an annual underwater insp. In June 85,a puncture in the subject diagonal was revealed during close visual inspection. The repair offshore is scheduled to start mid September 85.

16-Aug-80 PLATFORM SA Accident occurred when deck was lifted from barge to place it onto the jacket. There were two unsuccessful attempts, and in each attempt the ropes gave way resulting in damage to the barge in the first and to the deck in the second. Repairs will be handled locally.

17-Apr-80 PLATFORM SA Jacket fell into sea while being fitted onto leg of rig. See also accident 11-Jan-1980. 11-Jan-80 PLATFORM SA The jacket of the "platform SA" sank while it was launched at Bombay high oilfield. Mishap probably due to a leakage in the

compressor system at the time of the mechanical launching. Jacket was salvaged with the help of cranes and divers and was then installed at the site.

01-Jun-77 HEATHER,2/5,A Suffered damage during piling operation when a steel pile was accidentally dropped, striking one of the "bottle" legs and fracturing pile sleeves. Production delayed probably six months (to February 1978).

18-Nov-76 NINIAN SOUTH,3/8A External corrosion was discovered on an import riser pipe. One of three flow- lines has to be replaced. 29-Aug-75 AUK,30/16,A Visibility below 50 yards. Collision with supply vessel. Production delayed for 3 weeks. 12-Mar-75 UNKNOWN,TRINIDAD JACKET Jacket on barge '299'. Delivery to Amoco Trinidad Oil Co.. During launching, the jacket slipped off the barge and subsequently

floated in an angular position. Platform was to be launched in sheltered water due to prolonging storm. It was under way to be installed when interrupted by storm.

25-Oct-74 FRIGG,10/1,DP1 Location: the elf/total group at the 'Frigg' gas field. The buoyancy tanks failed as the platform was tilted from a horizontal to a vertical position about 3 km from the installation site. A new 20 mill usd platform is under construction. Field production delayed about one year. Platform was refloated July 7 1975. Will be used for other purposes.

06-Jun-74 SAMAAN Barge 'MM 151' transporting platform overturned and sank. No attempts to recover jacket. 05-Feb-73 EKOFISK,2/4,A Half the deck section dropped into the water. The wire broke while lifting the deck section from the building site to the pontoon for

transport to Ekofisk. Repaired March 22, expected cost: several million NOK. 09-Oct-70 AGOSTINO Ready for use when found inclined. Submerged part of support columns reinforced by further internal piles. 04-May-04 South Pars platform, SPP1 A man was killed while working on the installation of the jacket for one of the gas platforms for the South Pars field off Iran. The

accident happened when the piles were being loaded from a barge to the Stanislav Yudin crane ship. Both Statoil and seaway heavy lifting have appointed internal commissions of inquiry to find the cause of the accident. Statoil is operator for the development of the offshore part of phases six, seven and eight. The deceased was contracted for construction and installation of the jackets for the gas platforms. No more information available.


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Table 4.5 FPSO/FSU Under Construction Incidents [1]

Accident Date


27-Dec-98 JOTUN,25/7,FPSO Jotun B was undergoing hook up/commissioning activities when the incident occurred. No production or drilling activities was performed. A hydraulic oil leak in the east fire pump was detected and thought to be a maintenance issue initially but pulling of the pump was found to be required. 300 - 400 l of oil was lost within the pump caisson. All hot work in connection with the hook-up was suspended. The repair period was estimated to 2-3 days. No more information available

30-Jan-99 JOTUN,25/7,FPSO The incident occurred in platform hook-up and commissioning phase. Two smoke detectors in room 108, 1st floor, living quarters detected gas. All personnel were mustered. Site inspection showed that smoke was still present in the room and the initial investigation showed that the feeder within a switchboard had short circuited resulting in damage to the bars and surrounding insulation supports. No injuries to personnel. No more information available.

Table 4.6 TLP Under Construction Incidents [1]

Accident Date


04-May-95 HEIDRUN,6507/7,TLP During towout of tension leg no. 2 to the Heidrun field, the clamps for the pontoons broke and the leg sank in 240 m waters at position N 64.37.5 and E 08.03.7. The leg has been located and is lying flat on the seabed. The operator plans to salvage the leg. No further information available.

23-Jun-89 GREEN CANYON,184 Four of the structure's tendons sank while enroute to installation site. Cause is being investigated, but rests of the tropical storm allison may have accelerated the sinking. Installation was carried out without the four tendons. Production would not begin until the four missing ones were installed. Estimated startup of production was second week in November.

01-Nov-82 HUTTON,211/28,TLP Cracks in steelwork for the Hutton field prod. Platf. Built at Nigg bay on the Cromarty Firth. The cracks are so widespread that large sections may have to be scrapped. However, Conoco might be able to repair cracked sections.


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4.2 FAR data

4.2.1 OGP FAR Data

As at the date of preparation of this datasheet, [6] is the source for the recommended FAR data, replacing all other FAR data provided in the original E&P Forum datasheet. However, users of these data are advised to consult the most up-to-date annual OGP Safety performance indicators reports as they become available. Though limited in recording period, this is considered to offer a modern, stronger insight into construction FAR than many other sources. Other data sources have been reviewed to identify alternative or more extensive FAR analysis. The UK HSE publishes annual statistic reports (Offshore Injury, Ill Health, and Incident Statistics) and it is noted that the Maintenance/Construction category in these offers the closest match to the Construction category as defined in this datasheet. For 2007/2008, the Maintenance/Construction category contributed 72 incidents, or 37.5% of all the incidents and also had the most major injuries (13 incidents, or 29.5%). In 2006/2007 [10] the equivalent values were 2 fatal incidents (2 fatalities) (100% of total), 15 major (39% of total) and 60 severe (38% of total). The HSE data does not present a FAR breakdown for the Maintenance/Construction category. In overall terms a single FAR value per annum, or on a rolling basis is not provided. The HSE data combines fatal and major injury data in presenting 3-year rolling results. The OGP data [4],[6] have been analysed in more detail to determine if further breakdown of the reported Construction FAR is feasible. The OGP report presents a breakdown of the overall annual FAR, with further breakdown for onshore/offshore and contractor/ company personnel. Though not accurate, some estimate of onshore and offshore Construction FAR could be determined from the reported data. • From 2006 data ([4]) the overall FAR was 3.92, with 4.64 applicable onshore and 1.58

offshore. • From 2007 data ([6]) the overall FAR was 3, with 3.0 applicable onshore and 2.9

offshore. Offshore FAR contributions increased in 2007, with the capsize of the Bourbon Dolphin which claimed 8 lives. The 2-year average onshore overall FAR allocation is 3.82 ((4.64+3.0)/2) and the offshore overall FAR is 2.24 ((1.54+2.9)/2). Continued collection of OGP data will enable better 3- and 5-year rolling average estimates to be made in the future. The overall average Construction FAR for 2006 was 2.63 ([4], p63) and that for 2007 was 2.33 ([6], p62) If the overall average FAR ratios are applied to the Construction FAR, the following approximate average Onshore and Offshore Construction FAR are determined. • Average construction FAR (2 year average) = (2.63+2.33)/2) = 2.48 • Average overall FAR (2 year average) (= (3.92+3.0)/2) = 3.46 • Onshore average construction FAR = 3.82/3.46 × 2.48 = 2.74 • Offshore average construction FAR = 2.24/3.46 × 2.48 = 1.60 The onshore and offshore average construction FAR values are considered approximate; analysis of the actual detail of the OGP electronic database will yield more accurate values.


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13

The finding that the onshore construction FAR is higher than the offshore construction FAR overturns the previous E&P Forum datasheet which postulated that the offshore FAR was higher.

4.2.2 Comparison with other industries Comparing overall FARs with other industries as detailed in the original E&P Forum datasheet is no longer seen as offering significant value and has not been included. The OGP now has a wealth of data where it is possible to analyse data by geography, operation/activity type and incident severity along with trending. This is of much greater value than comparison with other industries.

4.2.3 Construction FAR breakdown by Region It is conceivable that the OGP database enables this, although no attempts have been made to postulate this using mathematical manipulation of the reported data.

4.2.4 Norwegian Construction Data The average frequency of fatalities for the period 2001 up to and including the first half of 2008 on the UK Continental Shelf is 2.9 per 100 million manhours against 1.2 on the Norwegian Continental Shelf [11] (Page 30). However the report does not lend itself to any interpretation of the contributions stemming from construction activity and reference to the old data presented in the E&P Forum Construction datasheet is now considered to be significantly out of date (very high values) and should be avoided.

5.0 Recommended data sources for further information Country-specific accidents and incidents data bases may be interrogated depending on the area that the installation will be deployed. As a starting point WOAD is a reliable source of information that can be interrogated in a variety of ways. There are more sources of data including, but not limited to, the HSE in the United Kingdom, the Occupational Safety & Health Administration (OSHA) in the United States of America, and the Petroleum Services Authority (Norway) and the increasingly valuable annual OGP reports which do illustrate a breakdown along regional lines on some of their construction statistics, e.g. Lost Time Injury Frequency but not on their FAR values.


©OGP 14

6.0 References [1] DNV, 2009. Worldwide Offshore Accident Databank (WOAD), v5.2. Search: February

2009. [2] DNV, 2004. Exposure Data for Offshore Installations 1980-2002, Technical Note 22,

DNV internal documentation. [3] UK Health & Safety Executive, 1996. The Offshore Installations and Wells (Design &

Construction, etc) Regulations, 1996. [4] OGP, 2007. Safety performance indicators - 2006 data, OGP report no. 391. [5] Trbojevic V.M., Bellamy L.J., Brabazon P.G., Gudmestad T., Rettedal W.K., 1994.

Methodology for the analysis of risks during the construction and installation phases of an offshore platform, J Loss Prev. Process Ind., 1994 Vol 7(No 4).

[6] OGP, 2008. Safety performance indicators - 2007 data, OGP report no. 409. noting erratum for FAR corrected in OGP Report 419

[7] DNV, 2007a. Accident statistics for fixed offshore units on the UK Continental Shelf 1980-2005, HSE Research Report RR566, Sudbury, Suffolk: HSE Books. (http://www.hse.gov.uk/research/rrhtm/rr566.htm)

[8] DNV, 2007b. Accident statistics for floating offshore units on the UK Continental Shelf 1980-2005, HSE Research Report RR567, Sudbury, Suffolk: HSE Books.

(http://www.hse.gov.uk/research/rrhtm/rr567.htm) [9] HSE, 2008. Offshore Injury, Ill Health, and Incident Statistics 2007/2008, HID Statistics

Report HSR 2008 - 1, Sudbury, Suffolk: HSE Books. (http://www.hse.gov.uk/offshore/statistics/hsr0708.pdf) [10] HSE, 2007. Offshore Injury, Ill Health, and Incident Statistics, 2006/2007, HID Statistics

Report HSR 2007 - 1, Sudbury, Suffolk: HSE Books. (http://www.hse.gov.uk/offshore/statistics/hsr0607.pdf) [11] Petroleum Safety Authority Norway, 2009. Trends in Risk Level in the Petroleum

Industry – Summary Report Norwegian Continental Shelf 2008. http://www.ptil.no/getfile.php/PDF/RNNP%20sam%20eng%2008.%20til%20nettet.pd

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