川东地区气田水回注系统风险评价方法

气田水回注系统包括地面处理站、输水管线、回注井筒、回注地层4 大子系统，各子系统的任一环节出现问题，整个注水系统都可能瘫痪甚至发生较大的环境污染，但目前气田水回注系统尚缺乏可靠、完善的风险评价方法。在对4 个子系统的失效因素统计分析基础上，利用各失效因素的统计频率确定了各级各项指标的权重，并借鉴肯特风险评价模型，从失效因素和失效后果两个方面建立了适用于气田水回注系统以及各子系统的风险评价方法与指标体系，提供了相应的安全等级划分标准。该评价方法既包含对系统可靠性的直接评价，也包括对泄漏后果的评价；既可用于各子系统的评价，也可将对各子系统的评价加权后用于整个回注系统。对川东气田实际回注系统的评价表明，评价结果与现场宏观认识一致，验证了评价方法的可行性。

Risk Assessment Method of Gas Field Water Reinjection System in#br#East Sichuan

Water reinjection system has four subsystems，including surface treatment station，water pipelines，reinjectionwellbore and reinjection layers. When a problem develops in any part of any subsystem，the whole water reinjection systemwill be paralyzed or lead to great environmental pollution，but there is not a reliable，perfect risk assessment method of gas fieldwater reinjection system. In this paper，all failure factors and their evaluation standards of each subsystem are summarized，andthe weight of each index is determined according to the statistical results for failure frequency of each failure factor. Complete，practical risk evaluation method for gas field water reinjection system and each subsystem was established through combiningwith the influencing factors evaluation of leakage and referring to Kent risk evaluation model. Meanwhile，two kinds of safetygrade division standard were provided. This evaluation method includes both direct evaluation on the reliability of the systemand the evaluation of the leak consequence；it can not only be used to evaluate of each subsystem but also can be used to evaluatethe whole reinjection system by weighting evaluation results of each subsystem. The risk evaluation of reinjection system inEast Sichuan Gas Fields agree with the on-site observation，which has proved the feasibility of this risk assessment method.