【摘要】 海上油气井开发过程井况复杂，存在井筒泄漏重大安全风险，风险评估作为支撑风险决策的重要分析工具，其可靠性直接影响风险管控的有效性。现有风险评估方法多依赖定性分析，且存在主观偏差与误差累积问题。为此，本文提出了一种超椭球-Z-number-事故树-贝叶斯网络（HE-ZFTA-BN）区间风险评估方法，在传统FTA-BN模型基础上，采取Z-number理论量化专家判断，融合超椭球区间模型计算预测概率并建立风险分级准则，结合重要度及后验概率模型确定关键风险因素，最后通过海上油气实例井评估验证模型有效性。分析结果表明：模型通过Z-number转化规则与超椭球区间算子，有效处理了专家评估的模糊性与不确定性，减少了点估计误差累积，且模型所得概率区间宽度小于传统矩形区间，避免了基本事件同时取边界值的极端保守问题，结果更为合理。实例井验证表明，该方法能够有效判定高风险井并识别关键风险因素，可为油气井生产泄漏风险评估及井完整性管理提供有效的量化方法与工具支撑。更多还原

【Abstract】 The well conditions during the development of offshore oil and gas wells are complex, presenting a major safety risk of wellbore leakage.As an important analytical tool supporting risk decision-making, the reliability of risk assessment directly affects the effectiveness of risk management and control.Existing risk assessment methods mostly rely on qualitative analysis and have problems of subjective deviation and error accumulation.Therefore, a hyper-ellipsoid-Z-number-fault tree analysis-Bayesian network(HE-ZFTABN) interval risk assessment method was proposed.Based on the traditional FTA-BN model, the Znumber theory was adopted to quantify expert judgments.The hyper-ellipsoid interval model was integrated to calculate the predicted probability and establish risk classification criteria, and the importance and posterior probability models were combined to determine key risk factors.Finally, the effectiveness of the model was verified through the assessment of an offshore oil and gas case well.The analysis results indicate that through the Z-number transformation rules and hyper-ellipsoid interval operators, the model effectively handles the fuzziness and uncertainty of expert evaluations and reduces the error accumulation of point estimation.Moreover, the width of the probability interval obtained by the model is smaller than that of the traditional rectangular interval, avoiding the extremely conservative problem of basic events taking boundary values simultaneously, and the results are more reasonable.The case well verification shows that this method can effectively determine high-risk wells and identify key risk factors and can provide an effective quantitative method and tool support for the risk assessment of production leakage in oil and gas wells and well integrity management.更多还原