Research On Wellhead Uplift Mechanism And Preventive Measures In Wenchang Gas Field

The gradual decrease of conventional oil and gas resources on land has prompted countries around the world to increase their exploration and development of marine oil and gas resources.During the development of offshore oil and gas fields,changes in key parameters such as temperature and production often cause wellhead uplift.During the development of Wenchang Gas Field,the wellhead uplift phenomenon is more serious.The wellhead uplift has an impact on the safety of other production facilities such as wellhead devices and auxiliary pipelines,which seriously threatens the production safety of the platform.In this paper,three high-production gas wells,including WC-A,WC-B,and WC-C wells,are studied in Wenchang Gas Field.Based on the analysis of the well structure and wellhead device structure and the geological characteristics of Wenchang gas field,the wellhead uplift mechanism of three wells in Wenchang gas field was studied,and the corresponding lifting force of each layer of casing tubes was calculated.Then the corresponding preventive measures were discussed,and the wellhead device after taking the measures was subjected to finite element simulation to analyze the overall stress situation.Finally,stress monitoring was performed on the wellhead devices of the three wells.The monitoring results are compared with the finite element simulation results,and the wellhead devices are checked for safety.The results show that the wellhead uplift of the Wenchang Gas Field is mainly due to the fact that there is a certain gap between the predicted temperature and production in the design stage and the actual production process.This gap caused the lifting force and lifting distance of the wellhead device to exceed the design stage estimates.Therefore,based on the combination of the wellbore structure and wellhead device structure,the reinforcement and prevention measures such as the installation of strengthening device were determined.The simulation results of the preventive measures are consistent with the on-site monitoring results,and both verify the rationality and safety of the preventive measures.It provides theoretical basis and technical support for the prevention of wellhead uplift in related oil and gas fields.