基于多因素影响的高含硫气田集输系统清管作业的定量风险评价

Quantitative risk assessment approach to the natural gas field gathering and transportation with highly sulfur-content based on the multi-factor effects

高含硫气田集输系统清管作业是维护湿气集输安全的重要措施,若清管作业操作不当,则不仅会影响工艺安全,还容易造成燃烧爆炸、中毒等事故,因此有必要进行清管作业定量风险评价方法的研究。针对清管作业中风险最大的作业步骤,基于多因素影响建立模型进行泄漏风险分析,该模型充分考虑组织因素、行政管理、个人特性、技术系统特性、任务特性等风险影响因素对泄漏风险的不确定性影响,并给出了算例。结果表明,利用该模型考虑到组织、管理、员工对清管作业风险的不确定性影响,可为清管作业安全管理提供参考。

The paper is engaged in a quantitative risk assessment approach to the natural gas field gathering and transportation system with highly sulfur-content based on the multi-factor effects so as to ensure its transportation and storage safety. For the said purpose,it is necessary to examine and identify the operation steps,the sealing failure of the blind plate and the inappropriate valve operation that may lead to the commonly met leakage hazards. At the same time,it is also intended to set up a model for analyzing the leakage risk cause based on the multi-factor causeeffect correlations. Actually,the analysis method we would like to propose is to consist of an event sequence diagram and a fault tree model to simulate the evolutionary process of the two different types of the initial leaking events in the operation of receiving pig. Therefore,first of all,we have managed to identify the risk influential factors of the initial events,which may include the organizational factors,the administrative management factors,the personal operation responsibility involved,the technical control features,the duty-distribution problems,and so on. And,secondly,it is also to determine the weights of the risk influential factors in accordance with the relevant standards,the technical documentation status-in-situ and the expert assessment in the barrier and operational risks,so as to properly evaluate the actual background status of the risk-influential factors in correspondence with the specific needs of the pigging operation. And,thirdly,it is necessary to work out the failure probabilities of the basic events through the quantitative analysis in answering to the industrial generic probability,weights and degrees of its risk influential factors,so as to gain the probabilities of different types of leakage in an approach to a case study sample. Thus,the results of our above study show that the leakage probability should be modified well in accord with the influential factors of the organization,the management and the operators of the system via the given model.Actually,the causative factors that may lead to the seal failure are supposed to be much broader than the leakage likeliness caused merely by the valve operation error. Therefore,it is of the primary importance to make the dynamic gradation and periodical classification of the risk influential factors of pigging operation and the leakage probabilities,in addition to the trend of the different kinds of leakage. Thus,the results of this research can be expected to provide a valuable reference to the safety management of the pigging operation.