The Study Of Groud Monitoring And Diagnosis System To Offshore Gas Well With Annulus Pressure

Sustained casing pressure is a common phenomenon in offshore gas well threatening productive safety,which may cause blowout,overflow and other accidents.To overcome the faults in diagnosing leaking status by using the present monitoring system,the monitoring and diagnosis system that can determine the specific reasons has been developed in this work.It can provide technical support to the integrity management of offshore production wells by timely and accurately determining the situation of annulus fluid when it is out of control.The research investigates the annulus pressure from several aspects:(1)A kind of multi-parameter monitoring method is proposed that include pressure,temperature,flow,gas composition and level position.The assessment of the level of annulus pressure risk,and diagnosis of leak location,leak status is implemented.(2)According to the monitoring and diagnostic procedures and characteristics of offshore production platforms,the monitoring and diagnostic system's working principle and structure are determined.And combined with self-developed automatically pressure increase liquid instruments,ground monitoring and diagnosis system suitable for offshore production platform is developed.(3)A monitoring and diagnostic software is developed by using Matlab editor,which contains real-time multi-channel data acquisition module,data process module,so ananlysis and diagnostic module,results report output module,the specific cause analysis of annulus pressure gas well and pressure risk evaluation can be realized.(4)Field test of ground monitoring and diagnosis system has been carried out,it demonstrate that the monitoring and diagnosis system have reasonable structure,stable,precisely reflecting annulus pressure condition.Therefore,this system can well meet the field working's security management needs.