海底油气管道系统风险评价技术研究

【作者】 谢云杰；

【导师】 姚安林；

【作者基本信息】 西南石油大学 ， 油气储运工程， 2007， 硕士

【摘要】 管道风险评价技术是上世纪70年代首先在国外发展起来的,具有很强的实践性和针对性,引入我国虽然只有短短十几年时间,却引起了广泛关注,已在陆上油气长输管道上得到了具体应用并取得了一定的理论成果和经济效益,但对于在海洋油气田开发中起重要作用的海底管道上的应用则相对落后,至今没有系统的评价技术。因此,如何研制一套针对我国海底油气管道系统的实际状况和特定环境的风险评价技术就是本文研究的主要任务。本文在借鉴国外管道风险评价技术基本思想和处理方法的基础上,结合我国海底油气管道设计、施工以及运行的实际情况,遵循我国海底油气管道技术标准和安全规范,通过对管线所经海域环境状况诱发管道事故的可能性分析,建立海底油气管道系统失效故障树,并对故障树进行了定性和定量分析。利用专家判断和模糊集合理论相结合的方法得到各基本事件的发生概率和顶事件的发生概率,即管道失效的概率,还对各基本事件进行了重要度分析,进一步确定了系统的薄弱环节。通过故障树分析和风险辨识,建立海底油气管道系统风险评价的指标体系,该体系对通用的体系模型进行了一定的修正,在一级指标中增加了自然环境影响指标,这是为了突出显示海洋环境影响给管道带来的风险;在事故后果评价中选用了环境模块,这主要考虑到事故对海洋环境的破坏;由于不同指标因素对管道风险的影响程度并不一样,即权重不同,在基于统计数据和我国海底管道的实际状况的基础上利用层次分析方法对各级指标权重进行了调整。由于海底管道所处环境的特殊性,对其观测和测量都有很大的难度,在没有潜水员和救生设备的情况下往往就无法进行,其结果必然带有比陆上管道更大的模糊性和不确定性,再加之海底管道发展较晚,各类统计数据缺乏更不能形成规律,因此本文采用指标评分法与模糊数学相结合的模糊综合评价方法来进行评价,以使评价结果更科学,更符合客观实际。最后,对可接受风险准则和风险控制方法进行了研究,并根据评价结果的不同风险等级提出了降低或规避风险措施。在以上研究的基础上,开发研制了一套具有针对性的“海底油气管道系统风险评价软件”来提高评价的效率和准确性。更多还原

【Abstract】 Pipelines risk assessment technology is developed abroad firstly in seventies of last century and has strong practicality and pertinence. It is only more than tens years from the technology has introduced in our country, but it has actually aroused the widespread interest and widely applied in the pipelines of on land and has obtains certain theory achievement and economic efficiency. But it is relatively backwardness in the application of oceanic oil and gas pipelines that has been playing a more and more important role in the national economy, until now it haven’t a systemic appraisal technology. So, to develop a set of risk assessment technology which aimed at the actual conditions and the specific environments of oceanic oil and gas piping system in our country is the main content of this article.With the fundamental thought and processing method of pipeline risk assessment technology overseas, unifying the actual situation in design, construction and runing, and following the technical standard and security specifications of the oceanic pipelines in our country, using the possibility analysis of the pipeline accident that caused by the environment which the pipeline passes through, the fault tree of oceanic oil and gas piping system have been established in this article. Then the qualitative and quantitative analysis to the fault tree have been carried on. With the hybrid approach employing fuzzy set evaluation and subjective estimation, the probability, the probability importance and the criticality importance of the basic events of the fault tree are determined, the failure probability of the top events is calculated too, and so the weak section of the system can be easily found out.With the analysis and the risk identification in the fault tree, the factor system of the oceanic oil and gas pipelines has been established. In the course of the establishment, some certain amendment to the general international system model have been carried on, add the natural environment influence factor in level of targets items mainly for the prominent influence of marine environment to the pipelines. Simultaneously considering the influence of the accident to the marine environment, the environment model has been chosen in the accident consequence assessment. Different factor is certainly dissimilar influence to the risk of the pipelines, namely the weights are different, so, some adjustment have been carried on using the analytical hierarchy process to the weight of all levels of influences factor based on the statistical data and actual condition of oceanic pipelines in our country.Because of the particularity of the environment in which the oceanic pipelines locates, it is very difficult and even impossible to observe and survey to the pipelines unless the diver or the life appliance stand by. Therefore, it is inevitable that there are more fuzziness and uncertainty in the course comparing with the land pipelines, in addition, the development of oceanic pipelines is compare late, each kind of statistical data is lacks and cannot form rules, therefore, the multilevel fuzzy comprehensive evaluation that unifies the EST and the fuzzy mathematics has been applied in this paper to evaluate the oceanic oil and gas pipelines in order to make it more scientific and objective.Finally, the risk rank of the appraisal result has been classified, and the acceptable risk criterion and risk control measures have been discussed in this paper. Some alleviating measure to reduced or evade the risk have been proposed. With all the studies above, "the risk assessment software for oceanic oil and gas pipelines system" have been finished to enhance the efficiency and the accuracy of the evaluation.更多还原