螺旋流洗井液流失速特性

Stalling characteristics of spiral-flow flushing fluid

为了对环空中形成的螺旋流失速特性进行分析,给旋流洗井等工艺提供借鉴,通过螺旋流试验装置,利用PIV、瞬态压力测量系统和涡角测量仪,对洗井过程中液流失速的流场流线、速度、涡量特性以及压力场特性进行了分析。结果表明:中等旋度涡角的螺旋流失速水击衰减要平缓些;螺旋流失速水击涡量不再完全具有贴壁性;涡角较小或较大其断面涡量变化剧烈,径向波动较为明显;水击压力起伏的频率随涡角的增大而减小;随着涡角的增加,水击压力最大起伏量有所减小;油套环空内失速水击压力随时间变化整体平缓;而油管内、外壁压力差随涡角的增大而减小。

Using spiral-flow test apparatus,PIV,transient pressure measurement system and vortex angle measuring instrument,the stalling characteristics of annular spiral flow were studied to provide references for spiral-flow well flushing and other processes.Meanwhile,the flow-field streamline,velocity,vorticity and pressure field properties were analyzed for fluid stalling in the well flushing.Results indicate that the spiral-flow stalling water hammer with medium vortex angle presents a gentle attenuation;the vorticity of spiral-flow stalling water-hammer shows no complete adherence to wall;the section vorticity has drastic changes in case of the small or large vortex angle,and the radial fluctuation is obvious;the fluctuation frequency of water-hammer pressure is decreased with the increase of vortex angle;when the vortex angle increases,the maximum fluctuation volume of water-hammer pressure is reduced to a certain extent;the annular stalling water-hammer pressure of oil jacket changes gently over time;the pressure difference between inner and outer walls of oil tube is decreased with the increase of vortex angle.