Jack-Up Platform Towing Operation Risk Assessment Based On the Job Safety Analysis and Risk Matrix Method

With
the rapid development of offshore oil industry, jack-up platforms have become
the main equipments of beach and shallow sea offshore oil operations. As the towing operation is very frequently and risky (since towing is
frequently operated and of high risk), the prevention and control work of
towing operation accident is significant and challenging. For this reason, the risk identification,
evaluation, reduction and control measures for the jack-up platform towing
operation are important to ensure the safety of towing operations and have
great application value.

As effective risk assessment method, Job Safety
Analysis (JSA) is used to divide a job into several steps according to the
order of operations, and then risk identification and analysis are conducted on
the job steps progressively. JSA is a qualitative risk analysis method and can
only be used to analyze the potential risks occurred in the process of a job.
In the meantime, JSA, which based on the model ¡®risk level = risk probability x
risk influence degree¡¯, can be used to conduct the most direct quantitative
evaluation on the degree of  risk factors considering factors impact and
risk probability.

The Fig.1 shows the flow of the Job Safety Analysis, and the Table1
is a conventional job safety analysis table. The risk matrix used in the risk
assessment of China National Petroleum Corporation is given in this paper, such
as the Table 2 and Table 3.

Fig.1  The Flow Chart
of Job safety analysis

Table 1  The Job Safety Analysis Table

Table 2  Risk Matrix

Table 3  Risk evaluation number

In order to acquire the quantitative results about the
possibility and severity of an accident, this paper combines the risk matrix
evaluation methods with JSA analysis process and designs a new type of JSA
worksheet (as the table 4). Considering the characteristics of jack-up platform
towing operation and industry evaluation, risk matrix is used to calculate the
risk level of risk factors, and then the control and improvement measures are
put forward. As a result, the importance and risk level of different job steps are
presented as the guidance basis of the platform towing operation safety.

Table 4  The Job Safety Analysis Table
based on Risk Matrix