倾斜气井井筒携液临界流量计算方法

CALCULATING METHOD OF THE CRITICAL FLOW RATE OF THE CARRYING LIQUID IN THE INCLINED WELLBORE OF GAS WELL

根据气液两相流理论和质点理论，倾斜井筒中液滴在气体中的受力状态将随着井斜角的不同而改变，而液滴受力状态的不同最终导致了气液两相流态和气体对液体的携带能力的变化。因而，倾斜井筒的临界携液流量不能用常规的垂直井筒和水平井筒携液临界流量公式计算。以气液两相流态理论为基础，根据质点分析理论，推导得到了考虑不同井斜角的倾斜井筒携液临界流量公式。计算了倾斜井筒不同井斜角的携液临界流量，并将计算结果与水平井筒及垂直井筒携液临界流量公式计算结果相对比。研究结果表明，倾斜井筒的携液临界流量介于垂直井筒与水平井筒之间；随着井斜角的增大，倾斜井筒携液临界流量减小，倾斜井筒携液临界流量越接近垂直井筒携液临界流量，携液临界流量变化幅度越小。

According to the theories of gas ＆ liquid phase flows and particle/mass point, the forced states of the liquid drops in gas vary with the angles of inclination in the inclined boreholes, but the different states result in the changes of the gas ＆ liquid phase flow regimes and the carrying capacity of the gas to the liquid in the end. There-fore, the critical flow rate of carrying liquid in the inclined borehole can not be calculated by conventional flow-rate formulas adopted in those vertical and horizontal wellbores. On the bases of the theories of gas ＆ liquid phase flow regimes and particle, considering the different angles of inclination in the inclined borehole, the above suited formula is deduced and then the flow rates for the different angles are calculated. At the meantime, the computed results are compared with those of horizontal and vertical boreholes. The study results show that the critical flow rate in the inclined borehole is between those of vertical and horizontal ones ; with the increase of the inclination angle, the critical flow rate in the inclined borehole reduces, the closer to the critical flow rate in vertical one, the less of the changed degree for the critical flow rate in the inclined borehole.