欠平衡垂直环空中气液固三相间滑脱特性的试验研究

项目名称： 欠平衡垂直环空中气液固三相间滑脱特性的试验研究

项目编号： No.51304227

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 矿业工程

项目作者： 杨晨

作者单位： 中国石油大学（北京）

项目金额： 25万元

中文摘要： 岩屑、气体和钻井液在垂直环空中的三相流动是采用欠平衡技术钻井时经常出现的工程现象，其中气液固三相间的滑脱特性既是多相流体动力学的基本科学问题，又是钻井施工中亟需解决的工程难题。 本研究以试验为基础，采用透明的聚合物钻井液作为代表液体，对现有的PIV系统进行改造，使用与钻井液折射率匹配的玻璃来制造岩屑，配合荧光诱导技术，有效地解决了岩屑和气泡在三相流中的互相干扰问题；通过调节进气量来改变截面含气率；定电流法实时监测截面含气率；高速摄像机连续拍摄气泡的运动轨迹；压力传感器测量监测点的流体压力，系统地记录岩屑和气体在不同钻井液类型和排量、岩屑浓度和形状、截面含气率下的运动特性。通过试验结果揭示钻井液中岩屑与气泡的滑脱方式规律及相互影响机制，通过量纲分析与多元回归得出钻井液中岩屑和气体滑脱速度的具体表达式。 研究成果可以直接应用于欠平衡垂直环空内气液固三相流动的计算模拟，具有重要的应用价值。

中文关键词： 欠平衡；垂直环空；三相流；滑脱特性；试验研究

英文摘要： The three-phase flow of cuttings, gas and drilling fluid in upward annulus is a commonly encountered phenomenon when drilling wells using underbalanced drilling technology. The slippage characteristics of gas-solid-liquid is ont only a basic scientific problem in the field of multiphase flow dynamics, but also an urgent engineering issue in drilling construction. This research is based on experiments. The transparent polymer drilling fluid is adopted as the experimental liquid. The PIV system is refined in this study: the cuttings are made of refractive index matching glass to let the light penetrate the suspended fluid and the fluorescent induction technology is introduced to avoid the reflection effect of bubbles; the void fraction is adjusted by different gas inflow rate; the constant current process is used to measure the void fraction; high-speed camera is adopted to record the behavier of gas bubbles; the pressure sensor is introduced to measure the pressure. The motion characteristics of cuttings and gas is recorded by the experimental system with different liquid type and flow rate,cuttings concentration and shape, void fraction separately. The slippage characteristics of cuttings and gas will be revealed based on the experimental results. The expression of fall velocity of cuttings and gas in three-phas

英文关键词： Underbalanced；Upward annulus；Three-phase flow；Slippage characteristics；Experimental study