16 May Evacuation, escape & rescue
Due to many associated risks, safe evacuation from offshore installations has been of significant concern between stakeholders and emergency professionals. Evacuation from offshore installation may become necessary due to various reasons such as a gas leak, fire and explosion, blow out, structural failure, adverse weather conditions such as hurricane or even very rare conditions such as potable water contamination or drifting of unmanned barge in the sea. This article reviews some important elements in evacuation, escape and rescue operations from offshore installations.
The 2002 Ocean Ranger and the earlier Piper Alpha (1988) marine disasters initiated extensive enquiries, into the adequacy of marine evacuation, escape and rescue (EER) systems. In fact they were key drivers in the development of performance standards for the EER process. Following the Piper Alpha incident, 52 out of 106 recommendations in the Lord Cullen report were related to EER.
Inadequate training of personnel, unfamiliarity with the layout of the platform, lack of proper emergency drills, inappropriate evacuation and escape routes and unsuitability of emergency response & rescue vessels are just some of the ERR shortfalls noted in the Piper Alpha incident. It has been argued that insufficient evacuation procedures may have contributed to the high death toll. By contrast EER operations played a fundamental role in safeguarding crew members’ lives in the Deepwater Horizon rig incident.
Even though critical failures were identified during EER operations on the Deepwater Horizon rig some fortunate circumstances such as good weather conditions assisted the efforts of the supply vessel to evacuate or rescue 115 of the 126 from fire engulfed platform where 11 fatalities occurred prior to the evacuation stage.
Some fatal incidents like the 2007 Usumacinta disaster in the Gulf of Mexico where 22 workers died during evacuation by lifeboat, indicated more work was needed to mitigate risk during EER operations. More recently, in December 2015, in the Guneshli field in the Caspian Sea near Azerbaijan a fire on an offshore oil platform claimed the lives of 32 workers. Although more than 40 were rescued in an emergency evacuation of the platform this incident reignited the offshore evacuation topic as the blazing platform could not be quickly evacuated due to stormy weather conditions.
The preferred means of evacuation from an offshore installation is helicopter as it is considered the safest method and mostly has been used for planned and precautionary evacuations. However, limited capacity, time delays in responses to emergencies, vulnerability to installation hazards and weather limitations are now considered as drawbacks of evacuation by helicopter. Therefore in certain emergency situations such as fire and explosion using such method is not practicable and lifeboats are used as a secondary means of evacuation. Using a crane and any related passenger capsule or bridge link between the jacket and the installation, have been seen as other alternatives in evacuation methodologies.
Weather effects on EER
Chances of successful evacuation by lifeboats vary significantly with the weather conditions. Literature reviews indicate that in adverse weather conditions there is a high risk of crashing the lifeboat into the structure of the installation or the lifeboat being swept back into the platform structure before headway is achieved.
Following the fire, due to a rupture of the subsea gas pipeline, on the Guneshil platform , the majority of personnel went inside the lifeboats according to company evacuation procedure, however crew were unable to lower the lifeboats as they were afraid the extreme weather conditions, with wind speeds of more than 74 knots and wave heights exceeding 9 metres, would cause the lifeboats to smash into the platform or capsize on contact with the sea.
Therefore to avoid the blazing fire on the platform, the lifeboats were lowered to an appropriate height and left hanging awaiting rescue. However, the fire on platform and the high waves on the sea did not allow the rescue vessels to approach the platform and perform a rescue operation. Eventually one of the lifeboats fell into sea and collided with the platform substructure and nearby vessels, hampered by the violent sea and the wind, could only rescue the three personnel from the vessel and all other lifeboat passengers perished. The passengers of the second suspended lifeboat were rescued the next day when the weather subsided. It is obvious in such extreme weather conditions there was limited chance of survival if the crew had attempted to escape from blazing platform either by jumping into the sea or using platform life rafts.
Unfortunately planned evacuation and other measures were not adequately performed on the Guneshil platform … Assuming that all oil and gas operators in the region would have had access to metrological forecasts in advance thus able to take appropriate measures and mitigate the risks.
Escape defined as leaving offshore installations when the evacuation system has failed, mostly involves entering the sea directly. The decision whether to evacuate or escape depends entirely on the nature of the incident. When safe evacuation procedures fail, proper arrangements should be in place to escape from installation. This includes the installation of an adequate number of life rafts, means of descending such as scramble nets, ropes, escape chutes and ladders. However escape devices may cause people to enter the sea with little or no protection and likelihood of survival is lower than evacuation method.
Rescue, defined as a process of recovering a person following evacuation and escape from installation and taking to place of safety. Rescue from the sea is performed either by Fast Rescue Craft or helicopter. Even though a helicopter could perform rescue operation in high wind speeds locating personnel makes it difficult in high waves and winching time increases as wave heights increase.
Previous trials have shown winching operation is impossible if wave heights are greater than 2 metres. Rescue by Fast Rescue Craft is more weather sensitive as launch and recovery by Fast Rescue Crafts is highly dependent on wave height. Literature shows in wave heights over 3.5 metres and wind speeds over 49 knots rescue vessels will not launch their Fast Rescue Crafts for rescue and recovery purposes due to the inherent risk to their crew.
Training for successful EER
Training has a fundamental role in the success of EER operations and there are concerns about the suitability of training for offshore oil and gas installation personnel.
For instance, most lifeboat coxswains in offshore installations are very unlikely to have any marine qualifications or even marine background. Thus, 29 hours training by an OPITO approved training provider is only a starting point and the course must be supplemented by constant training and exercises.
In fact, training events held onshore, are only a small part of competence development in emergency response role. They cannot replace the need for regular offshore practices and assessment through focused drill, exercise and scenarios. Training providers have also admitted that such shore-based activities do not accurately simulate the real events but are useful to teach the procedures involved.
Equipment and installation design
Historically poor or faulty equipment has lead to numerous incidents during EER operations but international regulations and standards regarding equipment design and installation have been introduced to reduce further incidents. For instance, some regulators requires operating companies and contractors to evaluate the suitability of their lifeboats for evacuation in adverse weather conditions and perform EER Analysis to demonstrate the adequacy of their procedure for such conditions. In addition to this, analysis of EER should be an integral part of the installation safety case as well. Overall, the success of EER from offshore installation depends on factors such as proper risk assessment and defined control measures, appropriate design of installation such as escape routes and muster area, emergency equipment performance such as lifeboats, firefighting equipment and finally actions of related personnel in emergency situations.
Escape, Evacuation and Rescue operations involve so many risks therefore advance preparations is crucial. Fair weather conditions can play a vital role in the success of EER operations and adverse weather condition will increase the associated risks. Onshore based training is only a small part of competence development for those who have fundamental roles during emergency situations and should be complemented with regular offshore drills and assessment. Asset integrity is critical during EER operations and previous incidents when equipment asset integrity was compromised, accentuate the importance of such issue. Using well developed and maintained equipment has a significant effect in the outcome of Evacuation, Escape and Rescue operations.
The original article was first published on the SAFETY4SEA website. “Evacuating from blazing oil platform” http://goo.gl/OijTq3 / SAFETY4SEA.com