井下防喷器坐封后多相流瞬态流动规律研究

钻井钻遏高压、高产气层后,井漏、气侵及溢流等复杂情况多发.目前,井口防喷器的研究已日趋成熟,但对井下防喷器坐封后多相流瞬态流动规律的研究较少.为此,针对井下防喷器坐封后下部井筒复杂流动特性,建立了一套防喷器坐封后下部地层-井筒耦合瞬态流动数学模型及其数值求解方法,对井下防喷器坐封后压力分布及影响因素进行了分析.实例模拟...

Research on Transient Flow Law of Multiphase Flow After Down-hole Blowout Preventer Setting

When drilling encounters high-pressure and high-production gas layers, there are many complicated situations such as lost circulation, gas invasion and overflow. At present, the research of wellhead BOP has become more mature, but research on the transient flow law of multiphase flow about the down-hole BOP is inadequate. For this reason, in view of the complex flow characteristics of the lower wellbore after setting of the down-hole BOP, a mathematical model and numerical solution of the formation-wellbore coupled transient flow after setting of the down-hole BOP are established. The pressure distribution and influencing factors are analyzed. The simulation results of the example show that, after setting of the down-hole BOP, the wellbore pressure evolution at different depths is basically the same; under different formation permeability, the bottom hole pressure increases exponentially and then increases linearly; as the amount of gas intrusion continues to increase, the initial down hole pressures will eventually stabilize around the formation pressure.