深水钻井防喷器系统失效定量风险分析

为了准确客观的评价深水防喷器系统的失效风险，建立基于改进屏障和可操作性分析方法的风险评价模型。首先应用安全屏障框图识别深水防喷器系统的安全屏障，从人员、设备和技术三个角度建立了包含15个因素的评价指标体系和深水防喷器系统失效分析模型；然后根据文献公开数据，分别计算了深水钻井井涌和防喷器系统失效的平均概率；同时利用齐次泊松过程参数模型代替屏障和可操作性分析方法中确定事件发生概率的专家赋值法，提高了结果的客观性；最后对Block47-1井的防喷器系统可靠性进行了评价，并对影响因素进行了敏感性分析。结果表明:Block47-1井的深水防喷器系统失效风险符合事故调查报告中的风险状况；安全密度窗口[1]对深水防喷器系统可靠性影响最大，在实际工作中应该特别防范窄密度窗口带来的影响；验证了所建模型的科学性，可为深水钻井作业风险评价提供参考。

Quantitative Risk Analysis of Blowout Preventer System Failure in Deepwater Drilling

In order to accurately and objectively evaluate the failure risk of deepwater blowout preventer system, a risk assessment model based on improved barrier and operational risk analysis method was established. Firstly, the barrier block diagram was applied to identify the safety barrier of the deepwater bop system, and an evaluation index system with 15 factors and the BORA analysis model for the failure of the deepwater bop system were established from the three angles of personnel, equipment and technology. Then, based on the published data, the average probability of failure of the kick and BOP systems in deepwater drilling was calculated respectively. At the same time, homogeneous poisson process parameter model was used to replace the expert assignment method in classical barrier and operational risk analysis method to determine the probability of event occurrence, which improves the objectivity of the results. Finally, the reliability of the BOP system in Block 47-1 was evaluated, and the sensitivity analysis of the influencing factors was performed. The results show that the failure risk of deepwater blowout preventer system in block47-1 well is in line with the risk status in the accident investigation report. The safety density window has the greatest influence on the reliability of the deepwater blowout preventer system. The model is proved to be scientific and can be used as a reference for risk assessment of deepwater drilling.