Research On Dynamic Risk Assessment Technology In Offshore Drilling Process

As an important part of offshore oil and gas exploration and development,offshore drilling engineering possess the features of high risks,technology and costs,the operation process of which is confronted with many difficulties.In view of the risk factors existing in the process of offshore drilling for dynamic risk assessment,which not only has important significance for ensuring the safe and efficient conduct of operations,but also the prediction of risk changes.The main research work of this thesis is carried out as follows:(1)Based on the extensive investigation of offshore drilling accident data,statistics of the main types of accidents and distribution of accident platforms have been done,as well as the causes,treatment methods and consequences of typical accidents.(2)Based on the statistical results,the causes,consequences and preventive measures of five typical accidents that may occur in offshore drilling process are analyzed.(3)Based on Bow-tie and Bayesian network,a typical accident dynamic risk assessment model for offshore drilling is proposed,and probabilities of the nodes in the model are calculated and updated by using Bayesian inference.In view of the accident happened in drilling process for a certain offshore oil and gas field,the varying tendency with time of posterior probabilities of its safety barriers and consequences are determined by adopting the method of probability distribution function and Bayesian theorem.(4)Prevention and control measures of risk factors,process technology,typical accidents and failure of safety barriers in offshore drilling process are put forward,which to provide a reference for the development of risk prevention and control strategies.(5)The software that fits the dynamic risk assessment of offshore drilling process is developed,which realizes the management of accidents,the monitoring of process parameters and dynamic risk assessment,and provide a convenient tool for field application.