In high-temperature and high-pressure (HPHT) gas wells, the wellhead growth caused by temperature and pressure effects during production might damage the well integrity. A calculation model of the wellhead growth produced by temperature and pressure effects was built. For the case well, the maximum pressures of annulus A, B and C are 64 MPa, 48 MPa and 38 MPa, respectively. The maximum production and intervention time are 114.5 × 10⁴ m³/d and 540 d, respectively. Based on the calculation process, the maximum wellhead growth is 412.7 mm. The axial load caused by the multiple annuli pressure is second only to that caused by the casing axial temperature difference. Wellhead growth increases with the annulus fluid thermal expansion coefficient and decreases with the annulus fluid isothermal compression coefficient. The increasing annulus temperature difference might aggravate the effect of annulus fluid thermal properties on the wellhead growth. Selecting the casing with greater wall thickness and lower thermal expansion coefficient can reduce the wellhead growth. The annulus width has little effect on the wellhead growth while the annulus length will significantly change the wellhead growth. The wellbore multiple annuli pressure can increase the wellhead growth prominently. The annulus pressure management shall be introduced into the production. Optimizing the well structure and production plan and installing the wellhead monitoring equipment contribute to mitigating the wellhead growth.

在高温高压（HPHT）气井中，生产过程中由于温度和压力影响导致的井口生长可能会损害井的完整性。建立了温度和压力作用产生的井口生长的计算模型。对于良好的情况，环空A，B和C的最大压力分别为64 MPa，48 MPa和38 MPa。最大生产和干预时间为114.5×10 ⁴  m ³/ d和540 d。根据计算过程，最大井口增长为412.7毫米。多环空压力所引起的轴向载荷仅次于套管轴向温差所引起的轴向载荷。井口的增长随环空流体的热膨胀系数而增加，并随环空流体的等温压缩系数而减小。环形温度差的增加可能会加剧环形流体热特性对井口生长的影响。选择具有更大壁厚和更低热膨胀系数的套管可以减少井口的增长。环带宽度对井口的增长影响很小，而环带长度将显着改变井口的增长。井眼多环空压力可以显着增加井口的生长。环空压力管理应引入生产中。优化井结构和生产计划并安装井口监控设备有助于减轻井口的增长。