摘要
冲击工具、PDC钻头钻齿类型以及硬岩地层的配伍性是延长冲击工具和钻头使用寿命、获得最佳破岩效果的关键因素,但是目前相关研究较少。针对此,考虑旋转冲击钻井过程中轴向静载与冲击载荷、钻齿以及地层之间的相互作用,建立了常规钻井和旋转冲击钻井条件下单、双斧形齿三维破岩数值模型,对比了不同钻井方式下多齿破岩效果的差异性,分析了冲击载荷作用下单、双齿条件下岩石内部拉应力、压应力与剪应力的分布,揭示了冲击载荷作用下多齿破岩机制,研究了不同钻齿倾角和双钻齿间距条件下钻齿侵彻深度、切削面下岩石损伤以及钻齿受力变化规律。研究结果表明:在双斧形齿破岩过程中,岩石内部存在明显的剪应力及拉应力干涉现象;随着钻齿前倾角的增大,岩石剖面损伤面积、侵彻深度和钻齿切向受力均逐渐减小,前倾角为20°时为最佳切削倾角;在钻齿前倾角保持不变的情况下,增大钻齿间距会导致双齿之间的干涉效果逐渐减弱,残余岩脊变得更加显著;考虑岩石切削效果和钻齿受力情况,当双斧形齿间距为16 mm时,钻齿具有较高的破岩效率和较长的使用寿命。研究结果可为冲击钻井过程中PDC钻头类型的选择和钻齿的布局提供理论和工程参考。
The compatibility of percussion tools,PDC cutter types and hard rock formations is a key factor in extending the service life of percussion tools and drill bits and achieve the best rock breaking effect,but it has been rarely studied.In this paper,considering the interaction between the axial static load and the impact load,cutters and formation during rotary percussion drilling,a numerical model of single and double axe-shaped cutter threedimensional rock breaking under conventional drilling and rotary percussion drilling modes was established.The multi-cutter rock breaking effects under different drilling modes were compared,the distribution of tensile,compressive and shear stresses in the rock which is broken by single and double cutters under impact load was analyzed,and the mechanism of multi-cutter rock breaking under impact load was revealed.The penetration depth of the cutters,the rock damage under the cutting surface and the variation of the force of the cutters under different cutter rake angles and double cutter spacing were studied.The results show that there is obvious interference of shear stress and tensile stress in the double-cutter rock breaking process.As the front rake angle of the cutters increases,the rock section damage area,penetration depth and tangential force of the cutters gradually decrease,and the best front rake angle is 20°.Given the front rake angle,increasing the cutter spacing will lead to the gradual weakening of the interference between two cutters,and the residual rock ridge will become more significant.Considering the rock cutting effect and the force of the cutters,the double axe-shaped cutters spaced at 16 mm can achieve a high rock breaking efficiency and service life.The research results provide theoretical and engineering references for the selection of PDC bit type and the layout of cutters in the process of percussion drilling.
作者
冷有恒
王立新
陈鹏羽
刘荣和
席岩
Leng Youheng;Wang Lixin;Chen Pengyu;Liu Ronghe;Xi Yan(PetroChina Amu Darya Natural Gas Exploration&Development(Beijing)Co.,Ltd.;CNPC Chuanqing Drilling Engineering Company Limited;PetroChina Research Institute of Petroleum Exploration&Development;Beijing University of Technology)
出处
《石油机械》
北大核心
2025年第7期58-66,共9页
China Petroleum Machinery
基金
国家自然科学基金面上项目“CCUS工程多场耦合及跨时空尺度条件下井筒密封完整性失效机理及控制方法研究”(52374001)。
关键词
PDC钻头
斧形齿
钻齿参数
破岩机制
数值模拟
侵彻深度
切向力
钻齿间距
PDC bits
axe-shaped cutter
cutter parameter
rock-breaking mechanism
numerical simulation
penetration depth
tangential force
spacings
