目前凝析气井井筒压力计算仍在沿用常规气井的方法,由于对井筒相态考虑不充分,计算精度无法满足动态分析和生产管理的需求。本文从凝析气井井筒相态特性出发,结合井筒温度分布,以气液相平衡计算为基础,建立了凝析气井生产过程综合考虑井筒温度、相态变化的压力计算模型,运用隐式差分格式并结合具体实例对凝析气井生产过程井筒压力分布进行了研究和计算。从计算结果看,该方法考虑了井筒温度及相态变化,因而井底压力的计算结果与实际情况更接近,可以解决压力计无法下入产层中部或不能正常测试的问题,作为凝析气井压力测试的替代手段,在仅进行井口参数测量的情况下能够帮助完成凝析气井常规的生产动态分析工作,从而节省测试所需的大量人力、物力。
Up to now, researchers are still using the method used for conventional gas wells to calculate the wellbore flowing pressure of condensate gas wells, while the calculating accuracy can not meet the demand of performance analysis and production management without considering the temperature and phase behavior transition in borehole. From the analysis of wellbore phase behavior transition in the production process, combining with wellbore temperature distribution change, the pressure calculation model is established based on gas-liquid equilibrium calculation and solved with the four-point implicit difference scheme. At the same time, phase behavior transition law and pressure distribution in this process are studied. The calculating result agrees well with the actual situation and it shows that this calculating method considering the temperature distribution and the phase behavior transition can solve the problem that pressure gauge could neither be put in the mid- dle part of layer nor operate normally so as to save up a great deal of manpower and material resources.