摘要
文章运用CAD软件Pro/E,对152.4 mm球形单牙轮钻头的几种喷嘴组合所形成的井底流场建立了3 D模型,并应用软件ANSYS对流场模型进行分析。研究了喷嘴的结构参数对井底流速、井底压降的影响。提出了井底流场效果的评判:①较高的井底压降;②较小的涡旋;③较大上返速度。从多种喷嘴组合中找出能够形成最好净化井底流场的喷嘴组合。指出在其它条件不变的情况下,上、下喷嘴直径比为0.5 时,井底流速和井底压力降最大;而当上、下喷嘴直径比不变,L=75 mm时,井底流速和井底压力降最大。建议在单牙轮钻头水力系统设计时上、下喷嘴直径保持上小下大,直径比0.50左右, L取75 mm左右时可以获得较大的井底流速、井底压力降以及较小的井底涡旋;喷嘴出口处的设计时尽量做到圆滑过渡。
A 3-D model of bottom hole flow field formed by several nozzle combinations of 152.4 mm spherical zublin simplex bit was set up by applying the CAD software Pro/E, and it was analyzed through CAE software ANSYS. On the basis of studying the effects of nozzle structural parameters on the bottom hole flow velocity and pressure drop, the criteria for deciding bottom hole flow effectiveness were put forward, i.e. relatively great bottom hole pressure drop; relatively small eddy; and relatively high upward velocity. In order to pick out the optimal nozzle combination, which can form the bottom hole flow field with the best purification efficiency, from several nozzle combinations, it is pointed out in the paper that, when the other conditions are constant and the ratio of top nozzle diameter to bottom nozzle diameter is 0.5, the bottom hole flow velocity and pressure drop are the maximums; and, while the top nozzle diameter to bottom nozzle diameter ratio is constant and L is equal to 75 mm, the bottom hole flow velocity and pressure drop are the maximums also. It is suggested that, int he hydraulic system design of zublin simplex bit, the relatively great bottom hole flow velocity and pressure drop and the relatively small bottom hole eddy may be achieved when the smaller top nozzle diameter and greater bottom nozzle diameter are adopted, the diameter ratio is about 0.5 and the L is about 75 mm; and the design of nozzle exit should be round and smooth as far as possible.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2005年第4期98-99,共2页
Natural Gas Industry
基金
CNPC中青年创新基金资助
关键词
单牙轮钻头
喷嘴
数值模拟技术
流场
偏心距
流体力学
Drilling, Zublin simplex bit, Nozzle, Diameter, Numerical simulation, Bottom hole, Flow field
