平衡点法压井计算与应用

Calculation and Application of Balance Point Well Killing Method

平衡点法压井是一种气井喷空后,能够安全快速压井的方法。它的基本思路就是利用天然气放喷量计算出地层压力,计算得到压井液密度后,利用井口回压和气液两相流动所产生的压力来寻找平衡点后,改变排量,继续压井的一次循环法。根据地层渗流特性推导了溢流过程中较为精确的地层压力计算方法,并以气液两相一维稳定流动为基础,建立了计算平衡点的数学模型,给出了利用数值方法计算井底压力变化的详细过程;并且分析了压井过程中立管压力和套管压力的变化趋势并编制了相关程序。实例计算表明,所编制平衡点法模拟计算程序计算结果正确,可用于平衡点法压井模拟计算。

Balance point well killing method is a safety rapid killing method which used after the gas well blow- out. Its basic idea is to use natural gas choke amount to calculated formation pressure and use well backpressure and gas-liquid two phase flow pressure generated for balance point. According to stratum seepage characteristics, more exact formation pressure calculation method are deduced. Taking the gas-liquid two phase flow as the founda- tion, the mathematical model calculation is established for balance point and presented the numerical method to cal- culate the detailed process of bottom hole pressure changes. What＇ s more, analyzed casing pressure and pipe pres- sure variation trend during the well control process and compiled the relevant procedures. Numerical examples indi- cate, collocation of balance simulation program is correct, can be used for simulating of balance point well killing.