Risk Assessment Data Directory. Report No March Evacuation, escape & rescue

Transcription

1 Risk Assessment Data Directory Report No March 2010 Evacuation, escape & rescue 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

2 P ublications 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 practice throughout the world. The oil and gas exploration and production industry recognises the need to develop consistent 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. Disclaimer Whilst 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. Copyright notice 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. These Terms and Conditions shall be governed by and construed in accordance with the laws of England and Wales. Disputes arising here from shall be exclusively subject to the jurisdiction of the courts of England and Wales.

3 Contents 1.0 Scope and Definitions Scope Definitions Summary of Recommended Methods and Data Recommended Methods Application Generic Stages of EER Evacuation Decision and its influence on EER Analysis Helicopter Evacuation TEMPSC Evacuation Times and Failures Modes of Lifeboat Evacuation Activity Undertaken to Improve TEMPSC Evacuation Bridge-Link Evacuation Escape to Sea Rescue and Recovery Recommended Data Availability of Escape Routes to Muster Areas Lifeboat Embarkation Lifeboat Evacuation Frequency of Installation Evacuation Probability of Evacuation Success Escape by Sea Entry Operability of Evacuation and Escape Methods under Various Accident Circumstances Survival Times in Water Guidance on Use of Data Availability of Escape Routes to Muster Areas Lifeboat Embarkation Lifeboat Evacuation Frequency of Installation Evacuation Probability of Evacuation Success Escape by Sea Entry Operability of Evacuation and Escape Method under Various Accident Circumstances Survival Times in Water Development of Offshore EER Arrangements Post PFEER Activity in the UK in Relation to Evacuation, Escape and Rescue Review of Data Sources Recommended Data Sources for Further Information References OGP

4 Abbreviations: ARRC DC DoE EPIRB EER ERP ERRV ERRVA FRC GEMEVAC H 2 S HSE NPD OIM OREDA OSC PFEER PLB POB QRA SAR SBV TEMPSC UKCS Autonomous Rescue and Recovery Craft Daughter Craft (UK) Department of Energy (no longer exists as such) Emergency Position Indicating Radio Beacon Evacuation, Escape and Rescue Emergency Response Plan Emergency Response and Rescue Vessel Emergency Response and Rescue Vessel Association Fast Rescue Craft Trade Name for Gondola System for Hibernia Hydrogen Sulphide (UK) Health and Safety Executive Norway Petroleum Directorate Offshore Installation Manager Offshore Reliability Data On-Scene Commander Prevention of Fire and Explosion, and Emergency Response Personal Locator Beacon People on Board Quantitative Risk Assessment Search And Rescue Standby Vessel Totally Enclosed Motor Propelled Survival Craft United Kingdom Continental Shelf OGP

5 1.0 Scope and Definitions 1.1 Scope This data sheet provides Quantitative Risk Assessment (QRA) data and guidance for Evacuation, Escape and Rescue (EER) from offshore installations as this has the potential to be more significant in personnel risk terms compared to onshore installations. Total evacuations of installations are rare events and each has very different circumstances. Thus, data relating to real EER events are sparse and QRA tends to rely on detailed analysis of escalation scenarios and EER activities within each scenario. This datasheet contains a number of example data rule sets and general guidance for EER analysis. Assuming personnel have survived the initial events, personnel EER from onshore facilities tends to be less complex and of inherently lower risk. Qualitative analysis, geared towards provision of suitable escape routes and appropriate rescue and medical contingency planning, will normally be adequate. On some onshore facilities the provisions of temporary shelters are required for sheltering from certain toxic gas releases e.g. H 2 S. In addition some emergency procedures are required for remote onshore facilities such as being overdue in desert, cold climate and jungle environments. The data presented is for North Sea and the user should seek local legislation for guidance. It is noted that maintenance activities on Totally Enclosed Motor Propelled Survival Craft (TEMPSC) in particular have been a source of risk. QRAs do not typically distinguish this risk as part of EER analysis but take account of maintenance risk within the general occupational risk category. Specific guidance on TEMPSC maintenance risk is provided by the UK HSE in its SADIE (Safety Alert Database Information Exchange). 1.2 Definitions The following definitions are based on those within the UK Prevention of Fire and Explosion, and Emergency Response (PFEER) Regulations 1995 [1]. Evacuation Evacuation means the leaving of an installation and its vicinity, in an emergency, in a systematic manner and without directly entering the sea. Successful evacuation will result in persons being transferred to a place of safety, by which is meant a safe onshore location, or a safe offshore location or marine vessel with suitable facilities. Evacuation means may include helicopters, lifeboats and bridge-links. Escape Escape means the process of leaving the installation in an emergency when the evacuation system has failed; it may involve entering the sea directly and is the last resort method of getting personnel off the installation. OGP 1

6 Means of escape cover items which assist with descent to the sea, such as life-rafts, chute systems, ladders and individually controlled descent devices; and items in which personnel can float on reaching the sea such as throw-over liferafts. Rescue In the PFEER regulations, this is normally addressed as Recovery and Rescue. Recovery and rescue is the process of recovering of persons following their evacuation or escape from the installation, and rescuing of persons near the installation and taking such persons to a place of safety. Place of safety means an onshore or safe offshore location or vessel where medical treatment and other facilities for the care of survivors are available. The recovery and rescue arrangements are: Facilities and services external to the installation, such as vessels, public sector and commercially provided search and rescue facilities; and Facilities on the installation such as installation-based fast rescue craft. 2.0 Summary of Recommended Methods and Data 2.1 Recommended Methods Application All EER activities expose personnel to an element of risk. However, three broad classes of EER can be distinguished: Routine Practice. These might be organized numerous times per year at an installation to rehearse the procedures and use of the EER equipment. The timing and conditions of such activities can to a large extent be controlled so that personnel are not put at unnecessary risk. The risks stemming from routine practice are not typically documented as part of a QRA. The risks are however appreciated and the offshore and marine industries have undertaken activity to control these risks, for the offshore industry the work done by the UK Step Change in Safety group in relation to its guidance on the Loading of Lifeboats during drills [11] provides effective guidance on risk control. Precautionary. For example, these might occur in the event of a drilling kick, an unignited gas leak, a drifting ship nearby, a minor structural failure or threatening platform movements in rough seas. Such an activity is not usually done under great pressure, and there have historically been few fatalities in such events. Emergency. For example, these might occur in the event of an ignited blowout, leak from process equipment, a collision or a structural collapse. Such activities are usually performed with urgency. These are historically more likely to result in fatalities. In developing predictions about the frequency of EER activities, for a given installation, influences will include, for instance, local environmental factors, the nature and extent of processing facilities, and the intrinsic hazards of the process. A multitude of variables can influence the outcome success of offshore EER activities. In particular, the weather is an important factor. Should an emergency evacuation be necessary during severe storm conditions, the risks of the EER activities are greater. 2 OGP

7 As each installation has its own unique characteristics, it is necessary to model the EER operation to give some basis for EER effectiveness. This can be done by using computer models, manual calculation methods, or a combination of these Generic Stages of EER Table 2.1 presents the stages of EER as a possible set of descriptions for use in EER analysis. Figure 2.1 provides a basic flowchart for the key stages of offshore emergency response as defined by the HSE in its guide for offshore EER HAZOP [8]. The situation may require evacuation, escape or a mix of both. The stages of an EER are complex and need to be considered with care during a risk assessment. The stages shown in Table 2.1 should be tailored for the particular installation and its potential major accident scenarios. Table 2.1 provides failure modes for evacuation but does not suggest the effects of failure. It should be recognised that the various types of failure carry different levels of risk for participants. An example is given in Section Figure 2.1 Basic EER Stages OGP 3

8 Table 2.1 Generic Stages of EER Stage + Generic Description Alarm Appreciation of an incident. Access Movement from immediate area of the hazardous condition. Muster Personnel assemble in a place of refuge. Egress Personnel move from a muster/ refuge area to a point of embarkation Evacuation Typical Specific Descriptions Detection system warns of an unsafe condition. Control room operator decides that there is an emergency and starts emergency procedure. Using the public address system, personnel are told that there is an emergency. Personnel become aware that they should leave their work area. They move out of the immediate area. Personnel assemble in a designated muster /refuge area. Personnel move to the helideck or to TEMPSC boarding areas to await controlled embarkation Personnel leave the installation using the primary and preferred means, helicopter, or using the primary mainstay means, TEMPSC. Some Operators consider crane system use allowing personnel to be lowered to attendant vessels as an effective evacuation means. Use of Gondola type systems (GEMEVAC Hibernia) Possible Problems Detection fails. Delay (any cause). Operator error. Public Address System fails. Public Address System not heard. Personnel do not hear alarms and do not notice the hazard condition. Hazard condition incapacitates personnel before they can leave the area. Escape routes blocked due to hazard or other causes. Personnel ignore procedures and do not escape. Escape routes not understood by personnel. Environment within muster area not tolerable due to accident effects i.e. smoke, heat. Problems in maintaining order within muster/ refuge area Egress routes affected by the hazard Helicopters unavailable Lack of control Personal survival equipment (e.g. smoke hoods) unavailable Means unavailable (wholly or partly) Uncontrolled situation resulting in early departure, leaving others Means affected by hazard Means adversely affected by weather/ conditions Insufficient capacity. Failure during transfer/launch process. No vehicle at place where personnel have gathered. Failure in the organisation or in the judgment of leaders. Lifeboat or other vehicle damaged by fire/explosion. Means of transfer damaged by fire or explosion. Personnel injured by explosion while awaiting order to evacuate. 4 OGP

9 Stage + Generic Description Escape Rescue Recovery to a Place of Safety Personnel make further transfer to arrive at shore or a place of safety before return to shore. Typical Specific Descriptions Personnel leave the installation by controlled descent provisions, ladders, stairs, chutes, personal descenders, davit launched liferafts, or uncontrollably by jumping Personnel in the water or in liferafts await external parties (air and marine) to provide rescue. Those in the water are the first priority, next liferaft then TEMPSC occupants. Helicopter shuttles evacuees to base/ship/nearby platform. Lifeboat transfers evacuees to helicopter then on to a place of safety. Lifeboat transfers evacuees to ship. Lifeboat reaches shore or another platform. Pick-up from liferaft and transfer to a place of safety. Those immersed rescued from water and transferred to a place of safety. Those immersed arrive at, and are then recovered to, a place of safety. Possible Problems Access to controlled descent prov-isions hampered Hazard effects Debris in the water Descent devices do not work Adverse weather/ visibility Inadequate external support Unavailable, inappropriate or damaged personal survival equipment (lifejacket, survival suit, etc) Personnel injury Those in water affected by cold, heat or other effects of an incident. Possible shark attack in tropical waters. Adverse weather Lack of control on TEMPSC disembarkation Accident during pick-up. Rescue vehicle suffers accident. Ineffective support facilities on recovery vessel OGP 5

10 2.1.3 Evacuation Decision and its influence on EER Analysis The decision on whether or not to evacuate the installation is made by a designated On- Scene Commander (OSC), typically the Offshore Installation Manager (OIM). The Emergency Response Teams would advise the OIM of the severity of the incident. In most cases, the OIM would stand-by and wait for the response teams to control the incident, and then return the installation to normal operations. Depending on the severity of the event, the installation layout, the weather conditions, and the response teams' capabilities, the OIM may choose to evacuate the installation. The choices are: Remain on the installation until the incident is over. This may be adopted for small incidents (e.g. false alarms, minor oil leaks etc), but these are not usually modelled in a QRA. It may also be adopted for major incidents of short-duration (e.g. large isolated process releases) where it is considered that staff in a muster/refuge area are safer to remain onboard Evacuate non-essential personnel only. Incidents where a fire-party or other essential crew can be left on the installation are considered to be precautionary evacuations, and are often not modeled a QRA, since accident experience indicates a very low level of fatality risk. Evacuate all personnel. This emergency evacuation is the only case typically analysed in offshore QRA and is outlined in the evacuation model within Figure 2.2 that can be utilised as a basis for EER analysis. Figure 2.2 EER Analysis Decision Model 6 OGP

11 2.1.4 Helicopter Evacuation Use of helicopter to evacuate is only possible in situations where both helicopter(s) and helideck are available. Some potential major accident scenarios would make it very dangerous to utilise helicopter transportation. Heat, smoke and flames from fires tend to propagate upwards and can impair a helideck facility. Helicopter evacuation is often more available for performing precautionary evacuations. Any evaluation of helicopter options must include an assessment of: The time scale of the supposed incident. The possible timing of the incident in relation to the availability of helicopters and crew (i.e. day or night). The defined evacuation plan i.e. to shore, ships or other installations. The possible problems in the access, mustering and loading process TEMPSC Evacuation In the event that evacuation by helicopter is not possible, generally, evacuation will be attempted by TEMPSC. The critical features affecting the risks of evacuation by TEMPSC are: Availability of TEMPSC suitable for launch, given the event necessitating evacuation. The choice of which TEMPSC to use, if there is spare capacity. Time required to load and launch the TEMPSC compared to the time for the event to escalate. The risk of an unsuccessful launch in the prevailing weather conditions. The risk of an accident during recovery of personnel to a place of safety (ERRV) Times and Failures Modes of Lifeboat Evacuation Table 2.2 presents a more detailed analysis of evacuation failure modes, which is drawn from [2]. This provides a framework for discussion and analysis. For analysis of existing installations, analysts should be able to use measured times from trials and exercises in place of the typical times shown in the table. The design of a TEMPSC to withstand physical effects due to an incident can also affect the success of an evacuation. OGP 7

12 Table 2.2 Typical Times and Failure Modes for Evacuation of a North Sea Installation by 40-person TEMPSC Action (with Indicative Duration) Muster Go to stations Head Count Order to abandon (5 to 15 mins) Prepare to launch Embark (4 to 10 mins) Start to lower Descend under control to near sea level Final descent to sea Release (1 min) Move away from installation Stay intact while awaiting pickup Personnel recovered successfully Recovery unit reaches shore Possible Problems Effects of incident. Escape ways blocked or unusable. Alarm ignored or not observed by personnel. Problems of command. Muster area exposed to heat or smoke. Craft damaged by effects of incident. Engine defect. Gear stuck. Sea cocks jammed. Craft damaged. Personnel injured. Premature descent. Access blocked. Other delays. Release/cable/brakes jammed, craft hooked up on gear and various other mechanical defects. Craft hits structure due to wind. Premature release of craft from falls. Wires too short. Release fails. Craft damaged by effects of the incident (heat, fire, blast, fire on sea). Steer into structure. Blown back into structure. Tides carries craft into structure. Mechanical failures. No pickup means. Craft not located. Craft sinks or capsizes before recovery. Injured person die before recovery. Excessive delay in pickup leads to death or injury of personnel. Mistakes during recovery. Failure of mechanism. Helicopter or ship suffers failure Activity Undertaken to Improve TEMPSC Evacuation The offshore oil and gas industry has seen efforts to improve the design, hardware and management of EER issues. Such improvements will achieve a reduction in risk for personnel. For example, TEMPSC design and operations improvement studies have covered: Assessment of Onload and Offload release mechanisms, to reduce the chance of premature erroneous release. Improved Clearance / Offset of TEMPSC from installations TEMPSC mounted at right angles to the structure or at its corners so as to allow a straight course away from the structure, also creating reduced wind and marine loads which would tend to bring the craft closer to the installation Improved vessel maneuverability, some adopting use of bow thrusters. Better visibility for TEMPSC Coxswain Better maintenance of TEMPSC launch mechanisms. More consideration given to the practicalities of recovering personnel from TEMPSC. Improved impact resistance of TEMPSC Development of Freefall TEMPSC 8 OGP

13 Development of the Preferred Orientation and Direction (PrOD) system to translate craft orientation in descent to an optimal heading and then translate descent potential energy into forward thrust. Currently additional effort is being applied to the safety of Freefall TEMPSC in relation to issues associated with increased average offshore worker mass and its effect on craft load distribution, canopy strength etc. Increased mass effects are also being addressed for conventional davit fall TEMPSC Bridge-Link Evacuation This essentially relates to an evacuation from an adjacent installation e.g. a drilling platform which is connected to the central platform by a bridge within a large production complex. If personnel are able to reach the central platform where evacuation normally takes place, the potential evacuation means where warranted are either by helicopter or TEMPSC as discussed above Escape to Sea Events that lead to the need for evacuation of the installation may also impair the means of evacuation or access to them. In such a case, personnel will have to leave the installation using escape means e.g. liferafts. The critical features of escape to the sea are: Availability of means of escape to the sea, such as ladders, scrambling nets, ropes and personal escape equipment. These may be impaired by the event requiring the evacuation. The reliability of the available means of escape, which is typically expressed in terms of the fatality rate among people using it Rescue and Recovery The purpose of the rescue and recovery arrangements is to ensure prompt recovery to a place of safety of personnel evacuating by TEMPSC, or entering the water during escape or because of a man overboard (MOB) incident, (Note MOB not typically assessed in QRA). This is normally achieved through arrangements with local search and rescue (SAR) helicopters and standby vessels/ Emergency Response and Rescue Vessels (ERRV) as specified by the installation s Emergency Response Plan (ERP). The critical features affecting the risks of rescue and recovery are: Location of the SAR helicopter. Response / launch times for the SAR helicopter and SBV/ERRV. Speed of the SAR helicopter and SBV/ERRV. Capacity of the SAR helicopter and SBV/ERRV. The time taken to rescue people from the sea, compared to their survival time in the prevailing conditions. This depends on the availability of suitable rescue craft, their reliability and performance in the rescue task, the environmental conditions affecting survival times and rescue performance, and the clothing and survival equipment used by the people in the water. OGP 9

14 The potential for accidents involving rescue vessels and helicopters. 2.2 Recommended Data The following sub-sections discuss the data and rule sets utilised in the EER analysis. There is little or no further update on the EER data used by the industry, hence the data and rule sets presented in the report are mainly adopted from OGP member database 1996, unless otherwise stated. The industry focus has been on making practical improvements in hardware rather than enhancing the nature and basis of EER analysis. Such practical improvements have been highlighted for TEMPSC evacuation in Section and for other general EER activity in Section 3.9. The rule sets describe the adopted principles in the EER analysis and may be further developed in conjunction with the installation specific EER arrangements. The rule set will ensure consistent approach and provide a guideline on industry best practice for EER analysis. Note that much of the data set out in the following sub-sections has been provided by OGP members, in which case it should be taken as indicating the type of data required at each stage and values typically used, rather than definitive recommended values Availability of Escape Routes to Muster Areas Table 2.3 provides sample rule sets that may be developed to assess the availability of escape routes to muster areas exposed to heat radiation and smoke effects. Table 2.3 Sample Rule Sets for Criteria of Impassability of Escape Routes due to Heat Radiation and Smoke If the underside structure of a route formed by cladding and plate, is still intact, the escape route is impassible if heat radiation level at the underside of the escape route exceeds 37.5 kw/m 2. A route, separated from heat effects to the side by a clad wall but having a grated floor, is impassable if the heat radiation level on other side of the clad wall is more than 12.5 kw/m 2. Less than 5 kw/m 2 will cause pain in 15 to 20 seconds and injury after 30 seconds exposure [12]. Greater than 6 kw/m 2 will cause pain within approximately 10 seconds; rapid escape only is possible [12]. An unprotected route is impassable if the smoke concentration is higher than 2.3%. In addition, many companies adopt smoke obscuration criteria such that routes are deemed to be blocked if the visibility is less than 10 m. It is noted also that many companies provide escape packs with smoke hoods, although little credit is adopted for using smoke hoods for the access (immediate escape) stage as they are located typically in accommodation areas for limited use in aiding helicopter or TEMPSC boarding. 10 OGP

15 2.2.2 Lifeboat Embarkation Table 2.4 provides sample rule sets that may be developed to assess the inoperability of lifeboat embarkation areas due to heat radiation and explosion effects. Table 2.4 Sample Rule Sets for Criteria of Inoperability of Lifeboat Embarkation Areas due to Heat Radiation and Explosion Effects Any jet fire impact (with or without water sprays operating). Any pool fire impact (without water sprays operating). Any explosion impact with an overpressure higher than 0.2 bar [12]. Permanent damage to the supporting structure. A heat radiation level of more than 12.5 kw/m 2 to the underside or outside of the embarkation area Lifeboat Evacuation Table 2.5 shows the probabilities of success for TEMPSC evacuation based on computer model predictions. Table 2.5 Probabilities of Success 1 for TEMPSC Evacuation (Computer Model Predictions) Wind (Beaufort Force 2 ) (m/s) Calm (0-3) (0-5 m/s) Moderate (4-6) (5-14 m/s) Gale (7-9) (14-24 m/s) Storm (>9) (> 24 m/s) Notes: Davit-Launched [2],[6] Free-Fall [OGP Member] Success, in this context, is achieved when no fatalities occur during the TEMPSC evacuation event. Thus 100% of the personnel on board the TEMPSC will be safely transported away from the installation and potentially to shore. As a rule of thumb it is commonly assumed in QRA that 50% of the occupants of a failed TEMPSC will become evacuation phase fatalities and the remaining 50% are immersed with the potential to suffer rescue and recovery phase risk. 2. Beaufort refers to the Beaufort Wind Scale, an internationally recognized system of describing observed effects of winds of different velocities. Winds are grouped into speed categories from 1 to 12 and area referred to as Force 1, Force 2, etc. The Computer Model was the Escape model as documented within [6] developed by Technica, now part of DNV and is available within the NEPTUNE Software toolkit, upgraded as ESCAPE III to cater for mobile unit motion dynamics. It is noted that the probability of successful TEMPSC evacuation is strongly influenced by the facility layout. As a result of the research conducted in developing the ESCAPE model and by the associated D.En Guidance, installation designers and facility operators created greater clearance distances between TEMPSC and structures that could be impacted on descent and in offset sea level clearances to minimize the potential to be swept back towards the facility once released. By remounting new and existing TEMPSC from a parallel/side on mount to a perpendicular/end-on mount this reduced the wind loading on descent which could cause platform collisions and offered OGP 11

16 the ability to drive more quickly away (without a need to turn) when seaborne reducing the swept back collision potential. In addition, OREDA-92 [7] includes some recorded failure incident and failure rate data for davit launched TEMPSC Frequency of Installation Evacuation Table 2.6 shows the frequency of partial/total evacuation for the Northern North Sea. Table 2.6 Frequency of Partial/Total Evacuation (Northern North Sea) Survival Craft Evacuation Helicopter Evacuation per installation year [2] per installation year [2] Over a 25 year installation life, this implies a 7.5% probability that there will be a TEMPSC evacuation and 19% probability of an evacuation by helicopter Probability of Evacuation Success The actual success rates at each stage of the process of EER for a defined group of personnel can be translated into an overall success rate. Stages of EER and associated probabilities of personnel acting as described may be defined as follows: identifying alarm = P1 making local escape (access stage) = P2 reaching muster/refuge place = P3 effecting evacuation or escape (from muster/refuge away from installation) = P4 reaching place of safety = P5 As an example, consider escape of 5 people working in a process area in which there is a rapidly developing fire. It is assumed that evacuation is by TEMPSC. Weather conditions may be any of those observed at this location. There is a good back-up organization to recover personnel after they have transferred to TEMPSC. (Source: OGP member). P1 = 0.95 (Visual and thorough alarm system) P2 = 0.80 (Fire effects may overcome personnel) P3 = 0.98 (Good escape routes unlikely to be blocked) P4 = 0.85 (to include allowance for possibility of becoming trapped at the muster/refuge place. Also includes derivation for TEMPSC launching weighted for different weather conditions) P5 = 0.90 (Emergency organization for the installation retrieves personnel. Success is good except in poor weather) Overall Success = (P1 P2 P3 P4 P5) = ( ) = 0.57 for the 5 people in the area where the incident takes place. Note that the chance can be improved to 0.74 (P1 P2 P3) if people can stay on the installation. 12 OGP

17 2.2.6 Escape by Sea Entry Table 2.7 provides a sample rule set for the probability of immediate fatality due to jumping to the sea from a North Sea deck (a lower deck where staff could be expected to routinely work). Table 2.7 Sample Rule Set for Immediate Fatality Probability due to Jumping to Sea from a North Sea Lower Deck Fatality Probability 0.1 Source: Sample extract from a typical Rule Set document of an OGP member. Note: Does not allow for use of tertiary devices, such as rope ladders etc., or for distance to sea. Table 2.8 provides sample rule set that may be developed to assess the probability of fatality upon entering the sea to escape in the North Sea. Table 2.8 Sample Rule Set for Fatality Probability Upon Entering the Sea to Escape (North Sea Data) Stand-by vessel status Probability of fatality No stand-by vessel present Averaged over all weather conditions 0.8 Stand-by vessel(s) present. Calm Weather (Wind 0 to 5 m/s) No or Low Fire Effects at Sea Level 0.06 High Fire Effects at Sea Level 0.15 Moderate Weather (Wind 5 to 12 m/s) 0.22 Severe Weather (Wind >12 m/s) 0.92 Source: Sample extract from a typical Rule Set document of an OGP member. Notes: Probabilities cover full scope of evacuation: entering sea; remaining at sea surface; rescue. Personnel making a sea entry expected to be wearing survival suit and life-jacket. Data do not differentiate sea temperature effects on personnel survival rate. In reality, personnel survival time immersed in sea, depends on local sea temperatures and generic human endurance times Operability of Evacuation and Escape Methods under Various Accident Circumstances Table 2.9 shows the operability ratings of evacuation and escape methods under various accident circumstances. Table 2.10 shows the historical success rates for a number of evacuation and escape methods. OGP 13

18 Table 2.9 Operability Ratings of Evacuation / Escape Methods Under Various Accident Circumstances: Hazards, Evacuation Time, Weather Types of Evacuation/Escape means Preferred Evacuation TEMPSC Evacuation Escape to Sea means Radiant Heat Hazard Evacuation Time Weather Gas/H 2 S/ Smoke < 15 mins < 60 mins < 180 mins Calm Mod Severe Helicopter / 2 8 / 2 9 / Bridge / 9 9 / 9 9 / Direct Marine / 2 9 / 5 9 / Protected Access Unprotected Access Liferaft, Ropes, Jump etc. Source: OGP member. Notes / 7 9 / 9 N/A / 7 9 / 9 N/A / 8 N/A N/A Ratings: Lowest = 0, Highest = 9. These ratings are based on how operable the various methods of evacuation / escape are expected to be under different accident circumstances of hazard, evacuation time and weather. A N/A mark indicates that alternative methods of evacuation / escape would be used in these circumstances. Two marks are given for the evacuation times based on the separate cases of total People on Board (PoB) = 20 and total PoB = 200 respectively (i.e. 8 / 2 refers to 8 for a 20 man installation, 2 for a 200 man installation). Table 2.10 Evacuation and Escape Success Rates Types of Evacuation/Escape Preferred Evacuation TEMPSC Evacuation Historical Success Rates Helicopter Low 1 Bridge High Direct Marine N/A 2 Protected Access Unprotected Access N/A Low Escape to Sea means Liferafts, Ropes, Jumping etc. Low Notes Source: OGP member. Ranking Categories: High / Medium / Low 1. Helicopters have not generally been available in time for emergency evacuations. 2. No data, as these are more recent developments and are not widely deployed offshore as yet e.g. Hibernia GEMEVAC. 14 OGP

19 2.2.8 Survival Times in Water Table 2.11 shows the survival time in water adopted in the North Sea. These values do not account for times for injured staff where injured survival times in summer are 85% of those not injured and in winter 60%. Table 2.11 Survival Times (minutes) in Water [9] Sea State: Calm Moderate Rough Category Summer Winter Summer Winter Summer Winter Lifejacket and Survival Suit Lifejacket / No Survival Suit Insulated Immersion Suit with Buoyancy Lifejacket / leaking survival suit Lifejacket/ leaking survival suit with thermal immersion garment during winter No Lifejacket/No Survival Suit Survival times can be extended for warmer water environments with the following rough guidance, depending on a variety of factors such as body type, clothing etc: 70 to 80 F (21 to 27 C): 3 hours to indefinitely 60 to 70 F (16 to 21 C): 2 to 40 hours 50 to 60 F (10 to 16 C): 1 to 6 hours In warmer water factors other than hypothermia may become more important. 3.0 Guidance on Use of Data The following sub-sections provide guidance on use of data presented in Section to Availability of Escape Routes to Muster Areas The criteria shown in Table 2.3 are samples of rule sets that can be used to evaluate the number of fatalities to personnel trapped in a fire area over an extended period due to effects from a fire of long duration. The criteria may be considered conservative when escape is possible within a few minutes after the start of a fire. Rule sets should be developed specific to the circumstances. The Vulnerability of Humans datasheet provides data complementary to that given in Section Lifeboat Embarkation Similar to the above, the rule set for inoperability of TEMPSC embarkation areas should be developed specific to the installation circumstances. OGP 15

20 3.3 Lifeboat Evacuation The various references in Table 2.5 give a range of predictions for the success rate of TEMPSC evacuation. These data figures are not precise, but give an indication that launching of TEMPSC does not guarantee safe evacuation. The outlines of the various ways in which the TEMPSC evacuation process can fail are as indicated in Table 2.1 and Table 2.2. TEMPSC evacuation success data are generally predictions based on North Sea experience of davit launched TEMPSC. Installations in other areas may use craft which are not davit launched TEMPSC. This could affect the success rate for evacuation. 3.4 Frequency of Installation Evacuation Table 2.6 shows the predicted frequency of having to evacuate an installation is derived from generic information. Some installations may never have an evacuation, others may have several over their lifetime. Helicopter evacuation might not be achievable until some hours after the initiating event. Fire, smoke and gas presence can prevent the use of helicopter. For such cases, TEMPSC and bridge transfer (for bridge linked platforms) provide further alternative means of evacuation. 3.5 Probability of Evacuation Success The probabilities presented are based on typical OGP member database. Any probabilities used should be scrutinised and developed specific to the installation evacuation arrangement and facilities. 3.6 Escape by Sea Entry There are insufficient data on the use of liferafts to give reliable figures for the probability of fatality when these devices are available. The probabilities presented in Table 2.7 and 2.8 are sample extract from typical rule sets document of OGP member database. Similar to the above, probabilities used should be scrutinised and developed specific to the installation escape arrangement and facilities. 3.7 Operability of Evacuation and Escape Method under Various Accident Circumstances Tables 2.9 and 2.10 are provided to aid estimates of EER systems effectiveness under different accident circumstances. The data is qualitative estimate of the applicability and success rates for different types of EER equipment. 3.8 Survival Times in Water The survival times are taken from HSE Offshore Technology Report OTO [9]. Survival times may be multiplied by to give a factor of safety as suggested in guidance PBN 97/20 of HSE for demonstration of good prospect. 16 OGP

21 All of these references date from the late 1980s/early 1990s. There has been little subsequent development in this area, as explained by the following brief account. Prior to the PFEER (Offshore Installations (Prevention Of Fire and Explosion, and Emergency Response)) Regulations 1995 in the UK, a significant degree of EER analysis was performed associated with the Piper Alpha Disaster report by Lord Cullen which required EER Analysis as a forthwith study in advance of the Safety Case Regulations which were enacted in 1993 (Updated in 2005 [10]). Much of the new numerical analysis work was performed at this time building on the earlier DEn ESCAPE work involving Technica. The PFEER Regulations set out more firm requirements on emergency response issues, principal among which was the requirement to demonstrate a good prospect of rescue and recovery. The Regulations enabled the possibility of Standby Vessel sharing. A lot of industry application was then devoted to demonstrating good prospect, particularly in cases of SBV sharing. Post PFEER many SBV sharing studies were performed using analysis methods developed before PFEER. Industry activity then drifted away from numerical risk methods and focused more on the practicalities of effective rescue and recovery. Section 2.3 gives a more detailed account of activity observed post PFEER in the UK. 3.9 Development of Offshore EER Arrangements Whatever offshore evacuation technique is used, two areas have been developed to improve the success of EER, principally stemming from Lord Cullen s report on the Piper Alpha Disaster. Firstly there is the development of concept, specification and performance of Temporary Refuges. Secondly, there is increased allowance for human factors, comprising command, control, human behaviour and ergonomics in the design of equipment, procedures etc with significant efforts given to training emergency command teams in simulated exercises. Much work has been done in these areas and there is continuous focus from operators and regulators. A number of innovative EER systems are in various stages of development. Several systems have been adopted by operators as risk reduction measures and best available means for EER. Examples of these innovative systems can generally be grouped into the following categories: TEMPSC assist systems Individual Escape Devices Multiple Personnel Escape Devices Levels of operational testing and experience for each particular system vary. Due to these systems relatively limited usage within the industry, there are little or no data currently available Post PFEER Activity in the UK in Relation to Evacuation, Escape and Rescue It became obvious that a good prospect of rescue and recovery required the ability to deploy resources quickly enough to recover people before survival times were exhausted. Therefore effort was applied from two sides to this survival challenge: To improve survival times in water, and OGP 17

22 To deploy new and different resources to get to people in the water more quickly Improving Survival Times It became obvious that survival time was linked to the type of survival suits being worn. Zips and worn seals compromised suits and caused ingress of water, which reduced survival times, so new suits were developed and additional training provided to reduce such problems. The problems of incompatibility between various survival suits and lifejacket combinations became more obvious and efforts were applied to demonstrate effective combinations, with many companies performing mannequin water tests at sea. The survival time was additionally tackled with the widespread adoption of thermal immersion garment liners worn within survival suits in defined weather/sea conditions to enhance the good prospect. More recently, led by several companies from the mid 1990s, there has been the adoption of rebreather technology to enhance personnel s ability to survive helicopter ditching scenarios. This addresses the human response to cold water immersion, which induces breathing and water ingress if submerged. The rebreather allows breathing to take place drawing in previously expelled breath to facilitate submerged escape from the aircraft Reducing Recovery Times As an aid to faster recovery of personnel from the water, the use of personnel locator beacons (PLB), previously limited to TEMPSC, Helicopter and Liferafts, was adopted by many companies whose associated support response fast rescue craft had provisions to track the PLB signal. When using PLBs, it important to ensure that when activated these devices do not interfere with helicopter EPIRB signals. On the deployment of resources side, advances began with better systems of recovering personnel from the sea. Lessons learned on earlier emergency situations prompted: The development of devices such as the Jason s Cradle, Dacon Scoop The development of Caley davits for FRC quick recovery in rough weather with an inbuilt heave compensation device Lower freeboard, and better illuminated and defined SBV rescue zones. A SBV code of practice was developed to harmonise the specification of SBVs, outlining different classes of vessel essentially related to the POB on the installations they are attending. This was then developed more recently as the Emergency Response Rescue Vessel (ERRV) code. The specifications of equipment and manning requirements were developed to ensure effective resources could be available to rescue, recover, attend survivors and crew the vessels effectively. With respect to SBV, the industry began to increase the number, capacity, reliability, endurance and speed of fast rescue craft. From the mid 1990s, fast rescue craft began to develop towards the daughter craft (DC) principle. These craft were larger, had canopies and could operate somewhat independently of the SBV for defined periods. 18 OGP

23 This enabled more distant deployments and enabled closer support for example for helicopter operations between local facilities, greater support under shared SBV circumstances e.g. over the side work close in support. DC have greater weather limitations than FRC as their weight makes rough weather recovery a problem, limiting their deployment to moderate seas. Also from the late 1990s, BP and various partners began to advance the Jigsaw concept that would provide good prospects of rescue and recovery by a more focused deployment of higher specification SBV and offshore based Search and Rescue (SAR) helicopter provisions (essentially equipped with forward looking Infrared systems, for the location of those immersed, and winch recovery provisions). The Jigsaw vessels are equipped with Autonomous Rescue and Recovery Craft (ARRC). These are essentially vessels that can be deployed using dual davits, which have a Rigid Inflatable Boat basis but with large cabs over 2 decks allowing comfortable autonomous operations and effective recovery capabilities Non UK Developments Away from the UKCS and the North Sea, newer work has been applied in the field of Emergency Response towards colder and ice oilfield environments. The Terra Nova development demonstrated the need to keep TEMPSCs in warmed garage facilities to ensure quick, effective use. The Sakhalin developments have demonstrated the need for new thinking in relation to evacuating onto full or partial sea ice cover. More recently the Kashagan development in the northern Caspian Sea, icebound in winter, has required creative solutions for emergency response arrangements, also influenced by significant potential for high concentration H 2 S situations. 4.0 Review of Data Sources The principal source of the data presented in Section 2.2 is the data published by OGP. References [4], [4] and [6] include a useful overview of offshore EER, including fatality assessment, as well as evacuation modeling (helicopters, lifeboats, bridge, sea entry). OREDA-92 [7] includes some recorded failure incident and failure rate data for conventional davit launched life boats. The Vulnerability of Humans datasheet provides data complementary to that discussed in Section 2.2. Most of the data presented are generally based on the North Sea experience. Installations in other areas operating in different environmental conditions and operating standards may be subjected to area specific data. 5.0 Recommended Data Sources for Further Information There are limited data available for use in EER analysis, however, a number of organisations provide guidance on EER best practice through their websites, within the UK this includes the Oil and Gas UK (formerly known as UKOOA), the Health and Safety Executive (HSE) UK, Emergency Response and Rescue Vessel Association (ERRVA) UK, and The Step Change in Safety group. For Norway the Norwegian Petroleum Services Authority (PSA) (formerly the NPD) provides guidelines. For other offshore sectors local authorities can be referred to such Transport Canada, Mineral OGP 19

24 Management Services (US), Occupational Safety and Health Administration (US), US Coast Guard, and in general the International Maritime Organisation (IMO). 6.0 References [1] HSE, Prevention of Fire and Explosion, and Emergency Response on Offshore Installations. Not yet available electronically in full; link to summary information: ( ks&category%5fname=&product%5fid=2788) [2] Sykes, K, Summary of conclusions drawn from reports produced by, or made available to, the Emergency Evacuation of Offshore Installations Steering Group, MaTSU. [3] Technica, Escape II - Risk Assessment of Emergency Evacuation from Offshore Installations, OTH , London: HMSO, ISBN [4] Robertson, D, Escape III - The Evaluation of Survival Craft Availability in Platform Evacuation, Intl. Offshore Safety Conference, London. [5] Department of Energy, Comparative Safety Evaluation of Arrangements for Accommodating Personnel Offshore, Section 9 + Appendix 7. [6] Technica, Risk Assessment of Emergency Evacuation from Offshore Installation, Report F 158, prepared for DoE. [7] DNV Technica, OREDA-92, Offshore Reliability Data Handbook, 2 nd ed., ISBN [8] HSE, A Methodology for Hazard Identification on EER Assessments, RM Consultants Ltd, OTH [9] HSE, Review of Probable Survival Times for Immersion in the North Sea, OTO [10] The Offshore Installations (Safety Case) Regulations 2005, SI2005/3117, Norwich: The Stationery Office, ISBN [11] (UK) Step Change in Safety, Loading of Lifeboats during Drills - Guidance. Final%20Copy.pdf [12] International Association of Oil & Gas Producers, Vulnerability of Humans, DNV Report no /14, rev OGP

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