Research on monitoring and alarming system for hydrate in gas wells

When the wellhead temperature for gas wells is low, freezing accident in wellbore could happen because of hydrate generation. Through designing the monitoring and alarming system, the freezing accident can be avoided. The pressure and temperature distribution along wellbore is computed through multi-phase flowing theory, based on the data acquired from the wellhead. Comparing to the hydrate P-T Graph by the picture interpreting means, the results can judge the situation of the hydrate and show the depth range with the hydrate in gas wells, so that the system can monitor and alarm hydrate. The system contains three main functions: calculating the pressure and temperature in wellbore during production and well shutting; forecasting hydrate generation; design of alarming and prevention. The software made up by these methods can realize the aim to real-time monitor and alarm hydrate. Finally, the software of the system is shown with the suggestion to avoid hydrate during gas well testing and production.