井下电动清洗工具清洗性能数值模拟研究

Numerical Simulation of Cleaning Performance of a Downhole Electric Cleaning Tool

油气开采过程中,碎屑颗粒在井底容易沉积结块,影响后续油气开采进度及设备的正常工作,造成开采效率和经济效益降低。针对井底沉积碎屑的清洗打捞设计了一种井下电动清洗工具,该工具利用内置的电泵将井底的流体介质吸入之后,以冲洗裹挟的方式将碎屑带入到工具内部,并利用单向打捞篮和碎屑收集腔对碎屑颗粒进行收集。为进一步研究清洗工具在不同结构参数下清洗打捞性能,基于Fluent软件建立了井底流场模型,采用欧拉固液两相流模型和RNG k-ε 湍流模型得到了不同时步下的碎屑颗粒分布图和流场底部的剩余碎屑体积分数。仿真分析结果表明:当喷嘴数目分别为2个、3个和4个时,井底剩余碎屑体积分数为2.04%、1.49%和0.21%;当喷嘴安装角度与中轴线夹角为12°时,清洗碎屑速度最快,剩余体积分数最小;电泵排量为50 m^(3)/h时,具有较低的能耗,产生更高的清洗效率。研究结果可为油气安全生产及井下电动清洗工具的设计提供一定的理论与指导。

In the process of oil and gas production,debris particles tend to deposit and agglomerate at the bottom hole,which affects the production and the normal operation of equipment,reducing the recovery efficiency and economic benefit.To solve this problem,a downhole electric cleaning tool was designed.It has a built-in electric pump which sucks the fluid at the bottom hole,and then brings the debris into the tool by washing and wrapping.And it uses the one-way fishing basket and debris collection chamber to collect the debris particles.In order to study the cleaning and fishing performance of the cleaning tool with different structural parameters,a bottom hole flow field model was established based on the Fluent software.Euler solid-liquid two-phase flow model and RNG k-ε turbulence model are used to obtain the distribution of debris particles and the residual debris volume fraction at the bottom hole of the flow field.The simulation analysis results show that,when the nozzle number is 2,3 and 4,respectively,the bottom residual debris volume fraction is 2.04%,1.49% and 0.21%,respectively;when the angle between the nozzle installation angle and the central axis is 12°,the debris cleaning speed is the fastest and the residual volume fraction is the smallest;when the electric pump displacement is 50 m^(3)/h,it has low energy consumption and high cleaning efficiency.The study results provide a theoretical guidance for the safe production of oil and gas and the design of downhole electric cleaning tools.