速度管柱携气性能数值模拟

针对在气井生产后期气压减少,产量降低,运用小管径连续管速度管柱提升产量是目前常用的恢复气井生产的有效方法。为探究连续管速度管柱携液机理,研究了管柱尺寸、变径管锥度以及流体中气体占比对产气性能的影响,依据现场工况,基于计算流体动力学理论对速度管柱内部流场进行数值模拟分析,得到以下结论:连续管组合壁厚差值越大,出口处流体速度越高,根据分析结果确定优选壁厚组合为2.77、3.68、3.96 mm;在连续管壁厚组合确定时,变径管锥度对流体速度也会产生影响,根据现场工况锥度范围取5组数据进行模拟,结果表明锥度越小,速度越快,且锥度为0.000 2时,井口速度8.14 m/s最快;气井生产中,流体中气体含量越高,产量越大,根据常用气井气体含量进行分析,当气体占比为85%时,出口速度最快。研究结果可为气井生产后期,速度管柱作业提供一定的理论依据。

Numerical Simulation on Gas Carrying Performance of Velocity String

At the late stage of gas well production, the decrease of pressure leads to the decrease of production. It is an effective method to improve production by using small diameter continuous tube velocity string to restore gas well production. In order to explore the fluid carrying mechanism of the continuous tube velocity string, the effects of string size, taper and gas ratio in the fluid on gas production performance were studied. According to the field conditions and the CFD theory, the internal flow field of the velocity pipe string was numerically simulated and analyzed, and the following conclusions were drawn: The larger the wall thickness difference is, the higher the fluid velocity at the outlet is. According to the analysis results, the optimal wall thickness combination is 2.77mm, 3.68mm and 3.96mm. When the combination of continuous pipe wall thickness is determined, the taper of the reducer pipe will also have an impact on the fluid velocity. According to the field condition, five sets of data of taper range are taken for simulation. The results show that the smaller the taper is, the faster the velocity is.And when the taper is 0.0002, the fast outlet velocity is 8.14m/s. In the production of gas Wells, the higher the gas content in the fluid, the greater the output. According to the analysis of the gas content in common gas Wells, when the gas ratio is 85, the exit speed is the fastest. The research results can provide some theoretical basis for the velocity string operation in the later stage of gas well production.