注超临界气体井筒温度压力场计算方法

Calculation methods for temperature and pressure distribution in supercritical gas injection well

根据传热学、热力学和垂直管流理论 ,建立了注超临界气体井筒温度压力分布的数学模型 ,提出了节点解析法、数值差分法以及焓插值法 3种求解方法。对辽河油田静 35块高凝油注不同介质现场效果进行的对比计算结果表明 ,在 0～ 6 0 0m井深时 ,井筒温降很大 ,随井深的增加 ,温降逐渐变小 ,温度趋于稳定 ;压力随井深的增加逐渐变为线性增加。利用节点解析法和焓插值法计算均能得到满意结果 ,其中解析法结果最为准确 ,而用数值差分法求得的温度偏高。

According to the theory of heat transfer, thermodynamics and the vertical pipe flow, a mathematical model for calculating temperature and pressure distributions in well bore was established. Nodal analytic method, numerical difference method and enthalpy interpolation method were used to solve the mathematical model. The calculations of different materials injected in Jing-35 Block of Liaohe Oilfield showed that temperature decreased dramatically within the well depth of 600 meters, and then decreased slowly with the depth increment. The pressure in the vertical well bore increased linearly with the depth increment. Satisfactory results have been achieved by using nodal analytic method and enthalpy interpolation method. The accuracy of nodal analytic method is the best. The temperature achieved from the numerical difference method is higher than the normal temperature, and the pressure is lower than the normal pressure.