Hydrocarbons like methane, butane, propane, hexane and so on are known as the most widely-used organic compounds. Hydrocarbons are mostly used as the fuel for combustion because huge amount of energy is stored in the covalent bonds between the hydrocarbons. Due to the increases of hydrocarbons, exploration and drilling have increased, about 10,000 offshore oil and gas are installed all around the world. Natural gas which is found beneath the seabed is drilled and extracted by the facilities in this huge structure which is known as offshore platform before sending it to further usage.
However, due to the complex structure and flammable components operation at the offshore platform, the risk of having accidents on the platform is quite high. Paik, Czujko, Kim, Seo, Ryu, Ha, Janisewski and Muisial (2011) claimed that more than 70% of the accidents that happen in offshore installation is caused by explosion and fires. This is not only significantly harming our human health, but also destroying the eco-balance of the both the natural and marine system. Piper Alpha accident on 6th July 1988 (Figure 1) had brought the attention of the globe onto the risk of explosion on offshore platform. The traditional viewpoint in offshore design was immediately replaced by risk-based approaches after the accident happened.
Risk need to be identified and analyzed before handling it. Hence, to identify the risk of explosion of offshore platform, one of the best means is to study and learn from the past incidents. One of the dominant risks when building and operating on an offshore drilling platform is explosion. This is due to the reason that oil-drilling platforms are usually operated under very narrow pressure, which is potential to escalate into a blowout. Meng, Chen, Shi, Zhu G. and Zhu Y. (2018) defined blowout as undesirable incidents which could lead to property loss, environmental contamination and even loss of life. Plenty of investigations and analysis were carried out immediately after the Piper Alpha accident. An inquiry for the cause of the Piper Alpha incident had been established by a government led by Lord Cullen (Shallcross D.C., 2013). From the studies, one of the major causes was inadequate work permit. Hendershot (2013) stated that one of the condensate pumps was taken down for regularly scheduled maintenance meanwhile a relief valve was removed which means that the pipe was open at that moment. Nevertheless, the workers who were in charge of the particular maintenance for both evening and night shifts did not communicate properly and put the standby pump into service. When the standby pump was put into service, flammable gas was instantly ignited and exploded.
Other than that, facility design issues are one of the reasons causing the risk, explosion on offshore oil-drilling platform, to be occurred too. When the operation is carried out at such a dangerous state, health, safety and environmental (HSE) is the most significant issue need to be considered to prevent the occurrence of the risk. Deluge system and fire walls are acting as the protection for the oil-drilling platform when explosion happens. Moreover, lacking knowledge of emergency responses could worsen the impacts of explosion. This can be proved by Piper Alpha incident. Although it had been functioning for three years, workers and even the management did not know what to do when the explosion occurred. This resulted in more deaths involved in the accident.
To deal with the flammable hydrocarbons, several studies have been conducted on evaluating the risks of offshore drilling platform. For instance, Analysis of Natural and anthropogenic Risks on Offshore Platforms (ARGO Project) was developed to analyze natural and anthropogenic risks for protection and safety of offshore platforms as well as provide technical assistant for the elaboration of recommendations from project findings (Caapiano P., Basco A., Ruocco A.D., Esposito S., Fusco G., Garcia- Aristizabal A., Mercogliano P., Salzano E., Solaro G., Teofilo G., Scandone P. C & Gasparini P. (2017). Other than ARGO Project, Quantitative Risk Assessment (QRA), Explosion Risk Assessment (EQA), Emergency Escape, Evacuation Risk Analysis (EERA) and Global Risk Assessment are the example of risk assessment which can be conducted when identifying and evaluating the risk of explosion on offshore oil-drilling platform. Global Likelihood of Failure (LoF) and global Consequence of Failure (GoF) assessment are included in the global risk assessment. Descriptive criteria (qualitative method) and scoring process (semi-quantitative method) are used to evaluate GoF which includes life safety as well as environmental and financial out-turns whilst rule-based scoring approach (semi-quantitative method) and structural reliability method are used to determine LoF (Guede, 2017).
For the case of Piper Alpha, the risk of explosion was evaluated that the unprofessional and irresponsible attitude of the workers was the major cause of the accident. If they were more aware of the which equipment was taken down for maintenance and which equipment was broken, the accident can be prevented and avoided.
After identifying, analyzing and evaluating the risk, the risks should be treated to minimize the chance of the risk to happen. Risk treatment includes avoiding the risk, change the happening or effects of the risk, share the risk and retain the risk. Building more safety facilities like deluge system and fire walls is one of the risk treatments that can keep the risk of explosion on offshore platform from happening. Hendershot (2013) claimed that the function of a deluge system is to protect the hazardous gas rivers while fire walls is to block the spread of fire when explosion happens. Furthermore, to share the risk, other than facilities, all the workers on the platform, no matter management or operators, laundry workers or even cafeteria workers should at least have the basic knowledge of emergency response. HSE training ought to be one of the criteria for all of the workers before going to work on the platform. This is very crucial because the knowledge determines between the life and death or safety of the worker themselves at the time of incident. Additionally, the occurrence risk of explosion on offshore platform can also be changed if more studies and risk assessments had been conducted.
To develop a safer and more trustable working area for offshore workers, risk of explosion on offshore platform needs to be taken into deeper consideration when building and operating the platform. Analysis like EQA, AGRO Project, QRA and EERA are the few of the most widely-used and significant risk assessment that carried out by the industries all around the world. With the suggestion of risk treatment from the studies of analyzing and evaluation of risk of explosion on the offshore platform, the risk could be minimized or even avoided. Other than Piper Alpha on 6th July 1988, explosion of Deepwater Horizon at Gulf of Mexico was one of the nearest and most serious cases happened back on 20th April 2010. It is encouraged to use past incidents as the reference on doing risk assessment as this not only provide the information but prevent the similar incidents to occur in the future again