开关井对气井井下管柱及气藏安全性的影响分析

An Analyses for the Safety of Tubing Strings and Gas Reservoirs during Producing and Closing

气井开井、关井作业时井口温度、压力随之变化,引起井下管柱变形与受力变化,引起地层压力变化和介质重新分布,进而影响井下管柱、封隔器与气藏的安全性。本文以陕北气田地质情况及常用管柱结构为例,利用管柱力学理论分析了开关井对井下管柱安全性、封隔器密封性能的影响,分析了开关井对气藏的影响。分析表明:就陕北气田储层情况、井身结构情况而言,开关一次井对井下管柱安全性、封隔器密封性能影响不大,也不会造成封隔器的蠕动;开关井会对气藏造成影响,气藏的性质不同,开关井对气藏造成的影响也不同,影响的方式与大小取决于孔隙度、渗透率、孔喉连通情况、孔隙结构特征、地层中岩石的矿物成分、气藏的驱动方式,以及是否存在底水、边水、酸性气体。

The temperature and pressure of gas wells change during producing and closing . With the changing of temperature and pressure, the deformation and loads exerted on tubing strings as well as the pressure and fluids of gas reservoirs change also, resulting in safety concerns . This paper analyzed the influences of producing and closing to tubing strings, parkers and gas reservoirs, taking Shanbei gas field as an example. It was found that the changing of temperature and pressure of gas wells during producing and closing resulted in the changing of deformation and loads exerted on tubing strings as well as the pressure and fluids of gas reservoirs, but did not result in safety problems.