Without a doubt, any activity aimed at the extraction of oil and gas carries risks. In recent years, the hydraulic fracture has been used more frequently to obtain energy, especially gas. It is true that this activity has been catalogued by a large number of states and scientific communities as dangerous. Additionally, there is scientific uncertainty as to the environmental impacts and human health damages that hydraulic fracture could cause. Therefore, it is important to draw up a careful plan of action in relation to the risk that this activity entails and that combined with the best available technology (BAT´s) can assure a higher safety level.
The solution is not a single method of risk containment, but rather the conjunction of several barriers that can build a risk restraint wall. One of the most commonly used methods in conventional oil and gas companies is the so-called bow tie diagram (Figure 1). The origins of this diagram/methodology are unknown, but it certainly developed after the accident of Piper Alpha in the North Sea in 1988 . This diagram/ methodology is widely used as a very visual tool to get an overview of the possible risks.
There are numerous technical reports and guidelines for risk assessment and risk analysis that use diverse terminology to deal with these issues whose basic concepts and specific terms are not always easily delimited . To clarify this terms the concepts of risk analysis, risk management and risk assessment will be mentioned. Risk analysis is used to identify the causes of harmful events, to determine the possible consequences of these events, to identify and prioritize certain barriers, and to form a basis for concluding whether or to what extent the system subject to this event is tolerable.
Figure 1: Bow-tie diagram to minimize and prevent damage from accidents with precautionary measures included.
Figure 1: Bow-tie diagram to minimize and prevent damage from accidents with precautionary measures included. Own elaboration from UTH, H., 2014. Technical risks and best available technology (BAT) of hydraulic fracturing in unconventional natural gas resources. Environmental Earth Sciences, 72(6), pp. 2163-2171.
Risk analysis refers to the systematic use of information to identify and estimate the risk it entails for individuals, goods and the environment (types of risk analysis). It always has a proactive approach, as it is always linked to the generation of potential accidents. The risk analysis has 3 phases according to M. Rausand (2013): 1) hazard identification, 2) frequency analysis and 3) consequence analysis.
Risk assessment in environmental and public health issues is a process based on science and findings on situations classified as dangerous that can be characterised. According to M. Atheensuu (2008), in different topics such as the identification of biological, chemical and physical dangerous agents; adverse risks concatenated with the agents mentioned above and their prevalence/frequency in time and the probability of occurrence of adverse effects, the uncertainty that could arise from them, is an aspect to reflect during the evaluation process. An analysis and a risk report are essential to approaching the evaluation.
On the other hand, risk management consists of making decisions at the place where such risks occur; it is a process of evaluating and selecting policies of action or inaction, derived from the results of the risk assessment and the implementation of these policies de facto.
Risk management, unlike risk assessment, contains social considerations such as political, technological, economic and public opinion regarding the specific situation.
At present in hydraulic fracturing processes, it is almost impossible to assume a 100% safety. But still these new energy sources are needed, hence the importance of analyzing other energy industries that assume high levels of risk to learn and apply them to hydraulic fracture extraction processes. A clear example can be seen in “The control measurements for preventing oil spills” proposed by N. Leverson (2017) :
– Providing appropriate incentives to change the safety culture: Relation between safety, profits and future sustainability.
– Industry standards: conforming guidelines, projects and strategies for the development of safe business industry.
– Industry self-policing: same as industry standards but at the inner level, including a strong internal audit department.
– Safety management systems: The core action of the application of these systems is to enhance the safety of operations by reducing the frequency and severity of accidents.
– Integration of safety engineers into operational decision making: Industries with strong safety programs often a person/group responsible for advising management at all levels of the organisation, during engineering design and development of new platforms and on the safety implications of decisions during operations.
– Certification and training: Constant learning by all levels of the industry is necessary.
– Learning from events.
– Hazard analysis: Improving the HAZOP analysis by introducing a digitalisation tool of an ongoing audit.
