Research on Risk Evaluation Method of Thermal Induced Annular Pressure in High-Pressure, High-Volume and High-Flow Gas Wells

The risk assessment method of annulus with pressure is researched based on the phenomenon of annulus with pressure in the three high gas wells in a block of Sichuan-Chongqing exploration area. Through the correlation calculation of the production performance data of typical wells, the main factors affecting the annulus pressure value are the wellhead gas volume, temperature and oil pressure, and the correlation coefficient is above 0.9, indicating that the annulus pressure type is thermally induced annulus pressure. To solve the problem of poor adaptability of previous analytical methods to dynamic well conditions, the big data analysis method is innovatively adopted, and the stochastic forest model algorithm is selected to build a thermo-induced annulus pressure risk prediction method. The error comparison results between the predicted value of the calculation model and the actual observation value show that the accuracy of the model reaches 98.25%, which indicates that the theoretical method established can accurately guide the annulus pressure control of three high gas wells.