盐穴地下储气库风险评估方法及应用研究

Risk analysis evaluation methods for underground salt cavern gas storage and case studies

随着我国地下储气库的建设投入逐步加大,如何有效防止地下储气库事故发生,在增强其运行安全性的同时合理利用资源,以获取最大经济效益,已成为储气库管理者重点关注的问题。为此,以盐穴地下储气库作为研究对象,将其划分为地下储气设施、地面站场设施和地面集输管线3个评价单元,采用系统分析和事故分析的综合分析方法,将该类储气库风险因素归类为腐蚀、冲蚀、水合物生成、设备失效、操作相关、机械损伤、地质构造因素以及自然力8类共性风险,包括14大类和45小类风险因素;研究建立了盐穴地下储气库风险评估方法,包括基于故障树技术的地下储气设施风险评估方法、地面站场设施的定量风险评估方法和地面集输管线的肯特管道风险评分法;并将建立的盐穴地下储气库风险评估方法应用于某盐穴地下储气库的风险评估,为盐穴地下储气库安全管理提供了依据,同时可为枯竭油气藏型和含水层型储气库的安全管理提供参考。

With the rapid development of underground gas storage in China, the operators of gas storage have to focus on how to prevent accidents and how to achieve the maximum economic profit by strengthening the safety while making rational use of resources.In view of this, the underground salt cavern gas storage, the research subject, is divided into three units for risk evaluation: underground gas storage facilities, ground stations and field facilities, and ground gathering & transmission pipelines. By use of the system analysis method in combination with accident analysis, the risk factors of the studied type of underground gas storage are classified into corrosion, erosion, the formation of gas hydrate, equipment failure, the operation-related work, mechanical damage, geological structure, and natural disasters, which are reduced to 14 types and 45 sub-types. Thus, the risk evaluation methods are developed for the underground salt cavern gas storage respectively for the said three evaluation units: The failure tree analysis (FTA)based method for underground facilities; the quantitative risk evaluation for ground facilities, and the analytic hierarchy process (AHP) Kent Grading method for ground pipe lines. These methods were successfully applied to the risk evaluation of a certain underground salt cavern gas storage, providing not only basis for the safety management of this storage but the reference for that of the aquifer gas storage or gas storage built on the depleted oil and gas reservoirs.