基于环空带压临界值确定高温高压气井临界产量

高温高压气井环空带压现象日益严重，环空带压过大可能破坏井筒的完整性，基于能量守恒定律和井筒径向传热机理，建立了井筒多环空温度场计算模型；综合考虑环空温度效应和体积效应，建立了环空带压控制方程，以某高温高压气井为例，开展了基于环空带压临界值确定高温高压气井临界产量的具体分析。研究结果表明:环空温度随产量和生产时间的增大先增加后逐渐稳定，相比生产时间，产量对环空温度的影响更加明显；环空带压越大，井下管柱安全系数越小，综合对比API RP 90标准和环空带压安全评价2种方法的结果，确定了各环空最大允许带压值，结合环空带压与产量的关系可得到高温高压气井的临界产量。研究结果对合理制定高温高压气井的生产制度具有理论指导意义。

Determining critical production of HTHP gas well based on critical value of annulus pressure

The annulus pressure in the high temperature and high pressure (HTHP) gas wells is an increasingly serious problem,and the excessive annulus pressure may damage the integrity of wellbore.A calculation model of the wellbore multiple annulus temperature field was established based on the energy conservation law and the radial heat transfer mechanism in the wellbore.The governing equation of annulus pressure was established with comprehensively considering the annulus temperature effect and volume effect.A specific analysis of determining the critical production of HTHP gas well based on the critical value of annulus pressure was carried out by taking a certain HTHP gas well as an example.The results showed that the annulus temperature increased first and then gradually stabilize with the increase of production and production time,and compared with the production time,the production affected the annulus temperature more prominently.The greater the annulus pressure,the smaller the safety factor of downhole string.The maximum allowable pressure value of each annulus was determined by comprehensively comparing the results of the annulus pressure safety evaluation method and the API RP 90 standard,then the critical production of HTHP gas well could be obtained according to the relationship between the annulus pressure and the production.The results have theoretical guiding significance for reasonably setting the production plan of HTHP gas wells.