Title

Jet Characteristics of Impeller Swirling Jet Nozzle

作者

牛似成王翔杨永印

Authors

Niu Sicheng Wang Xiang Yang Yongyin

单位

中国石化华北分公司工程技术研究院, 河南郑州 450006; 中国石油大学(华东)石油工程学院, 山东东营 257061

Organization

Engineering and Technology Research Institute, Sinopec Huabei Branch Company, Zhengzhou, Henan, 450006, China; School of Petroleum Engineering, China University of Petroleum(Huadong), Dongying, Shandong, 257061, China

摘要

为提高PDC钻头钻进水平段时的井底射流辅助破岩能力，开展了叶轮式旋转射流喷嘴的射流特性研究。利用k-ε双方程标准湍流模型，对叶轮式旋转射流流场进行了数值模拟，并采用旋流强度和流量系数评价了射流破岩能力。数值模拟结果表明，叶片扭曲角为115°~140°、直柱段无因次长度为0.6~0.8、收缩角为60°~70°时，流量系数和旋流强度可取得最佳值，射流破岩能力最强。根据不同喷距下的旋转射流破岩试验结果，分析了叶轮式旋转射流喷嘴的破岩特性，结果表明，同压降下叶轮式旋转射流破岩直径是普通直射流的近3倍，且喷距在7~11倍喷嘴出口直径时破岩直径最大。研究结果表明，叶轮式旋转射流喷嘴的破岩能力优于普通直射流喷嘴，且通过优化叶轮式旋转射流喷嘴几何参数可提高其破岩能力，加强井底清岩和辅助破岩效果，提高PDC钻头的破岩效率。

Abstract

In order to improve bottom-hole jet-assisted rock breaking ability while drilling horizontal section with PDC bit,the characteristics of impeller swirling jetting were studied.Using k-ε standard turbulent flow equation,the impeller swirling jetting flow field was simulated.The swirling intensity and discharge coefficient were used to evaluate rock breaking capacity.Numerical simulation results showed that the discharge coefficient and swirling intensity were optimal under the condition of blade twist angle 115°-140°,dimensionless length of straight tube 0.6-0.8,and the falloff angle 60°-70°,and the jet rock-breaking ability is the strongest.Those rock breaking tests showed that the hole diameter of impeller swirling jet was three times of that of straight jet under the same pressure drop,and the hole diameter was the maximum when the standoff distance was 7-11 times that of nozzle diameter.The studies above indicated that rock-breaking ability of impeller swirling jet was better than that of straight jet,and the rock breaking ability could be improved with the optimization of nozzle geometrical parameters.All these means could enhance bottom-hole rock cleaning and breaking effect,and also improve drilling efficiency of PDC bits.

关键词：

喷嘴; 旋转射流; 旋流强度; 流量系数; 数值模拟; 几何模型; 破岩效率;

Keywords:

nozzle; swirling jet; swirling intensity; flow coefficient; numerical simulation; geometric model; rock breaking;

基金项目

DOI

https://doi.org/10.3969/j.issn.1001-0890.2013.06.022