结构参数对气体钻井防沉屑工具性能的影响

Influence of structural parameter on performance of cuttings falling-prevent tool in gas drilling

针对气体钻井岩屑易沉积的问题,研制一种具有分流继能功能的防沉屑工具。利用计算流体动力学(CFD)技术研究分流喷孔结构参数(开孔斜度、开孔方位、喷孔线型)对防沉屑工具吹扫和推举性能的影响。结果表明:随开孔斜度和开孔方位增大,轴向射流动能急剧减小,切向射流动能缓慢增大;开孔方位增大,径向射流动能降低;流线型喷孔与直线型和曲直型喷孔相比,其射流动能损耗最小,轴向、径向和切向射流动能均最高;改变喷孔结构参数可以有侧重地增强防沉屑工具的径向、切向吹扫能力和轴向推举能力,以适用于造斜段、水平段及深部直井段的气体钻进施工。

A cuttings falling-prevent tool was developed to solve the problem of cuttings sedimentation in gas drilling.Using the computational fluid dynamics technology,the effect of the structural parameters of split-flow nozzle including nozzle gradient,nozzle azimuth,nozzle linetype on the sweeping and carrying cuttings capability of cuttings falling-prevent tool was researched.The results show that with the nozzle gradient and nozzle azimuth increasing,the axial kinetic energy of jet-flow reduces dramatically,the tangential kinetic energy of jet-flow grows slowly.When the nozzle azimuth angle increases,the radial kinetic energy of jet-flow brings down.Compared with streamlined and straight-line nozzle,the curved-straight line nozzle is the smallest wear and tear of jet-flow kinetic energy.Axial,radial and tangential kinetic energy of jet-flow are all the highest.Changing structural parameters of nozzle can enhance the radial and tangential sweeping capability and axial carrying cuttings capability of cuttings falling-prevent tool respectively,so as to adjust to directional,horizontal and deep vertical section in gas drilling.