摘要
目前国内尚无应用计算流体力学(CFD)方法对随钻扩眼工具进行分析的先例。为此,基于CFD方法,采用赫-巴流变模式和RNG k-ε湍流模型对随钻扩眼工具的内外部流场进行仿真计算。通过对流场流线形状和流线分布情况进行分析,着重研究了冲洗水眼放置位置、水眼出口大小和水眼后置角度等对非水基钻井液流场的影响。分析结果表明,后置式冲洗水眼不会产生涡流,可直接冲洗切削刀翼,因而设计时宜采用后置式水眼结构;后置式水眼的出口不宜太大,否则分流过多影响前方钻头工作;也不能太小,影响岩屑输送和切削刀翼温度的降低,设计时应考虑实际情况在5～6 mm的区间内取值;后置式水眼的后置角度不能太大,否则钻井液向上的速度分量衰减过快,设计时可根据具体结构在30°附近取值。
Based on the CFD method, the Herschel-Bulkely rheological model and the RNG K-S turbulence model were adopted to conduct a simulation calculation of the internal and external flow fields of the reaming tool while drilling. Through analysis of the streamline form and streamline distribution of the flow fields, the study fo- cused on the effect of the placement of the flushing nozzle, the size of the nozzle outlet and the nozzle postposition angle on the non-aqueous base drilling fluid flow field. The analysis shows that the postposition flushing nozzle will not produce any vortex and it can directly flush the cutting blade. Therefore, it is desirable to adopt the postposition nozzle structure in design. The postposition nozzle outlet should not be too large, otherwise too much shunt will affect the operation of the bit. Meanwhile, it cannot be too small, otherwise it will affect cuttings transportation and the re- duction of blade temperature. Its value should be taken between 5 -6 mm in design according to the practical condi- tions. The postposition angle of the post-nozzle cannot be too large, otherwise the attenuation of upward velocity com- ponent of drilling fluid will be too fast. The value can be taken near 30~ according to the specific structure in design.
出处
《石油机械》
北大核心
2012年第9期1-4,共4页
China Petroleum Machinery
基金
国家科技重大专项"钻井新装备新工具研制"(2011B-4301)
关键词
计算流体力学
随钻扩眼工具
冲洗水眼
赫-巴流变模式
流场模拟
CFD
reaming tool while drilling
flushing nozzle
Herschel-Bulkely rheological model
flow field simulation
