自进式直旋混合射流钻头结构优化与钻孔能力分析  

Structure optimization and drilling capacity analysis of a self-propelled straight-swirling mixed jet bits

作　　者：杜鹏 张汶定 DU Peng;ZHANG Wending(School of Mechanical Engineering,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学机械工程学院,安徽淮南232001

出　　处：《煤田地质与勘探》2022年第7期173-182,共10页Coal Geology & Exploration

基　　金：国家自然科学基金青年项目(51804007)。

摘　　要：自进式射流钻头作为水力喷射径向钻井技术开采煤系气的核心部件,对钻井效率有决定性影响。为获取直旋混合射流钻头结构的最优参数,采用Fluent数值模拟与室内钻进试验相结合的办法,分析不同钻头结构参数下三维流场的速度特性,给出优化准则,并通过钻进试验加以验证,得到钻头的最优参数:中心孔孔径1.2 mm,叶轮槽槽宽0.7 mm,叶轮长度4.5 mm,叶轮径向长度3.5 mm,倾角45°,混合腔腔长6 mm。并通过理论分析解释了不同参数对钻头钻进速度产生变化的原因,主要是通过影响直旋混合射流中直射流与旋转射流的通量,进而引起射流三维的变化。采用灰色关联分析法得出各参数结构对钻进位移的敏感性系数由高到低依次为:中心孔孔径、叶轮槽宽、叶轮径向长度、混合腔腔长、叶轮倾角、叶轮长度。室内钻进试验结果表明:优化后的射流钻头具有更高的钻进效率,在关联分析中对钻进效率影响最大的是直射流与旋转射流通量,且直旋通量比在0.54时,射流能量分配较合理。研究成果对径向钻井煤层气、天然气开采中钻头的设计与结构优化具有指导意义。As the core part of hydro-jet radial drilling technology for coal-measure gas extraction,the self-propelled jet drill bit has a decisive impact on drilling efficiency.In order to obtain the optimal parameters of the direct rotating mixed jet,the velocity characteristics of the three-dimensional flow field with different bit structure parameters are analyzed by the combination of Fluent numerical simulation and specific experiments,and the optimization criteria are given.The optimal parameters of the drill bit are obtained in the drilling test:the central hole of diameter 1.2 mm,the impeller groove of width 0.7 mm,the impeller of thickness 4.5 mm,radial length 3.5 mm,and inclination angle 45°,and the mixing chamber of length 6 mm.Through theoretical analysis,the reasons why different parameters change the bit drilling speed are explained.That is,the three-dimensional change of the jet is caused mainly by affecting the flux of the direct flow and rotating jet in the direct rotating mixed jet.The sensitivity coefficients of each parameter structure on drilling displacement are obtained by using gray correlation analysis from high to low are as follows:center hole diameter,impeller groove width,impeller radial length,mixing chamber length,impeller inclination and impeller thickness.The results show that the optimized jet bit has higher drilling efficiency.In the correlation analysis,the direct flow and rotating jet flux have the greatest impact on the drilling efficiency,and the jet energy distribution is more reasonable when the direct rotating flux ratio is 0.54.The research has guiding significance for the design and structure optimization of bits in the radial drilling of coalbed methane,and natural gas production.

关 键 词：直旋混合射流钻头 径向钻井 三维速度 灰色关联度 钻进试验 

分 类 号：TD231.62[矿业工程—矿井建设]