深水井筒在生产阶段受地层高温产出液的影响,温度场重新分布引起环空密闭空间的压力急剧上升,威胁井筒安全.为向深水油气井的井身设计和套管强度校核提供一定的依据,结合现场实例对基于状态方程和胡克定律计算模型和基于状态方程和温度压力耦合作用的迭代计算模型进行对比,对模型机理和影响计算结果的因素进行了分析.深水井筒中的环空流体介质复杂,井底高温及异常压力使得深水井筒中的环空中流体热膨胀系数和压缩系数对套管体积的影响难以利用胡克定律简化计算.结果表明,基于状态方程和温度压力耦合作用的迭代计算模型更适用于深水井筒的环空压力分析.
The deepwater wellhole is affected by high-temperature produced liquid of stratum in the production stage, and the redis-tribution of temperature ifeld causes the sharp increase of pressure of annular conifned space, threatening the wellhole safety. In order to provide certain bases for the wellbore design and casing intensity check of deepwater oil and gas wells, according to two kinds of calcu-lation models, namely, calculation model based on equation of state and Hooke's law and iterative calculation model based on equation of state and temperature and pressure coupling, as well as living examples on site, these two kinds of models are compared, the model mechanism and factors affecting the calculation results are analyzed, the annular lfuid media in the deepwater wellhole are complicated, and it is dififcult to conduct the simpliifed calculation of effects of coefifcient of thermal expansion and coefifcient of compressibility of annular lfuid in the deepwater wellhole on the casing volume by virtue of Hooke's law due to downhole high temperature and abnormal pressure. Pursuant to the results, the iterative calculation model based on equation of state and temperature and pressure coupling is more suitable for the annular pressure analysis of deepwater wellhole.