Real-Time Risk Analysis Of Deep Water Well Control Process Based On Non-Markov Stochastic Petri Net

As an important emergency operation,well control is of great significance to control and deal with various risk factors in the process of deepwater oil and gas development.Based on the characteristics of coupling evolution of well control operation process and well control failure risk,this thesis puts forward a risk assessment method based on time efficiency and suitable for accident development process.The main research work is as follows:(1)A corresponding NMSPN model is constructed based on analysis of well control technology and Petri net theories and in combination with characteristics of well control process for deepwater oil and gas exploitation.Time efficiency analysis is conducted on the Petri net model for well control process based on Monte-Carlo simulation technology to obtain the time-probability distribution of the total well control process.(2)The quantitative relationship between time efficiency and annulus casing pressure shall be established for the multiphase flow migration of oil and gas invasion in the wellbore during deepwater drilling;the risk assessment model for deepwater well control process shall be established by taking the severity of casing pressure shut-in as the evaluation standard and the quantitative relationship between well control operation time efficiency and well control risk shall be established.(3)Based on the method of time efficiency-well control risk assessment,the realtime risk analysis method for deepwater well control process is established by dynamically updating the risk assessment results by introducing the on-site real-time conditions and the actual completion of well control operations.