中文摘要：

对高温高压气井,井筒流体高速开采过程中产生的井口热应力和环空热膨胀压力会导致井口装置抬升,破坏气井井筒完整性。本文建立了环空热膨胀压力和井口抬升计算模型,结合某高温高压气井进行了实例分析。结果表明：环空热膨胀压力随着环空温差和流体热膨胀系数的增加呈线性增加,随环空流体等温压缩系数的增加呈线性减小;C环空热膨胀压力产生的井口热应力最大,A环空最小;单层套管存在自由段时,井口抬升随着环空热膨胀压力的增加呈非线性增加,当自由段长度相同时,井口抬升对C环空热膨胀压力最敏感;多层套管同时存在自由段时,环空热膨胀压力不会改变多层套管自由段长度对井口抬升高度的影响规律,但会导致井口抬升高度增大。

英文摘要：

For the high temperature and high pressure（HPHT） gas wells,wellhead thermal stress and annulus thermal expansion pressure caused in the process of production with high speed might result in the wellhead growth,and destroy the wellbore integrity.Annulus thermal expansion pressure and wellhead growth calculation models were established in this paper,a case study was conducted of a HPHT gas well.The results show that the annulus thermal expansion pressure increases linearly as the increase of the temperature difference and the fluid thermal expansion coefficient of the annulus,and decreases as the increase of the annulus fluid isothermal compression coefficient linearly.The thermal stress caused by the thermal expansion pressure of annulus C is the highest,and that caused by the thermal expansion pressure of annulus A is the lowest.When there is free section at the single casing,the wellhead growth increases non-linearly with the increase of the annulus thermal expansion pressure,under the same length of free casing section,the wellhead growth is most sensitive to the thermal expansion pressure of annulus C.When there are free sections at multiple casings simultaneously,the increase of the annulus thermal expansion pressure might increase the wellhead growth instead of changing the impact rules of the free section length on the wellhead growth.