高温高压含硫气井环空流体热膨胀带压机理

在高温高压含硫气井中，环空带压值过大将会影响正常生产，一旦超过允许值将诱发潜在的安全事故。针对开采过程中井筒温度升高使密闭环空流体受热膨胀而导致的环空带压问题，建立了高温高压含硫气井环空流体热膨胀带压值的计算模型，并进行了实例计算。结果表明，高温高压含硫气井环空流体热膨胀引起的带压值很有可能会引起生产管柱的失效，给油气井安全生产带来威胁。因此，有必要在井身结构设计、套管强度设计与环空保护液优选时，根据油气井正常开采的工作制度，降低开采过程中环空带压值并开展有效的环空带压管理，确保高温高压含硫气井的长期安全生产。

Mechanism of annular fluid thermal expansion pressure in HTHP sour gas wells

In HTHP sour gas wells, over high pressure in annulus will affect normal production. Once it exceeds the allowable limit, potential safety hazards will be evoked. In view of high pressure problem resulting from thermal expansion of annulus fluid due to the temperature increase during the production period, a calculation model was established for that pressure in HTHP sour gas wells. And case studies were then made. The results show that the heat induced annulus pressure can cause failure in production pipe string, posing threat to safe production. So when doing casing program planning, casing strength designing, and optimal annulus fluid determining, we had better to reduce the production heat induced annulus pressure and to manage the annulus pressure effectively while maintaining normal operation system, so as to ensure long term safe production in HTHP sour gas wells.