Study On Slug Flow Prediction And Production Parameter Optimization Of Offshore Oil And Gas Wellbore

Slug flow is the most common flow pattern during offshore oil-gas production,which is intermittent and unstable.The unstable flow of two-phase will cause pipeline vibration.Especially for risers in marine,their vibration characteristics become extremely complex,which has a great impact on the production of offshore platforms.In order to ensure safe and efficient production of offshore oil wells,slug flow model is established through theoretical analysis of slug flow dynamics and fluid-solid coupling of pipelines.The accuracy of the model is verified by two sets of experimental data at home and abroad.Combined with the fluid-solid coupling vibration model of pipeline,the flow characteristics of slug flow and the pressure fluctuation characteristics of pipeline are studied,and the influence of pipeline and fluid parameters on the inherent characteristics of pipeline system is analyzed.A slug flow prediction software for offshore oil-gas wellbore is designed by using the established model and multiphase flow calculation method.The sensitivity analysis of slug flow calculation results and optimization design of tubing parameters are carried out by using field production data to verify the validity and integrity of the software.Based on the data of an offshore oil well,the software is used to analyze the variation law of slug flow characteristics in well profile,and two methods of controlling slug flow,i.e.adjusting wellhead pressure and gas injection at the bottom of riser,are studied.Combining these two methods,the production parameters of oil wells are optimized,and the recommended parameters of wellhead pressure and gas injection volume are finally selected.The research shows that this method can control the occurrence of slug flow and reduce the hazards caused by slug flow.It is of great significance to the optimization design of production parameters of offshore oil wells.