复合载荷冲击破岩作为新的高效破岩技术之一可以解决复杂难钻地层机械钻速缓慢、钻具失效严重等问题.基于弹性力学和冲击力学理论,建立了复合载荷作用下压头的破岩模型,分析了模型因素对压头侵深的影响.同时,应用有限元软件分析了复合载荷作用下岩石位移和应力的响应.通过现场应用进一步证明复合载荷冲击破岩的提速效果.理论研究结果表明:该破岩方法可以在保证钻深基础上,减少钻具失效;还扩大了岩石的响应范围和载荷的作用区域,加剧了岩石振动的剧烈程度;当激励频率与岩石固有频率相同或接近时,岩石产生共振,整体振动位移达到峰值.现场应用效果表明,高频低幅轴向冲击工具应用井段平均机械钻速可达3 m/h,与常规钻具相比,平均提速可达67.65％.%Impacting rock under combined loads,as one of efficient rock breaking technology,can solve the drilling problem of complex hard formation,such as slow drilling rate,serious drilling tool failure.Based on the theories of elastic mechanics and impact mechanics,a rock breaking model of indenters was proposed and the effects of factors on the invasion depth were studied.Also,finite element software was used to analyze the response of displacement and the stress of the rock.At last,the effect of increasing speed under the impacting of combined loads was proved further through field applications.Results of theoretical research show that:the technology not only can guarantee the invasion depth,but also can reduce the drilling tool failure.It also can expand the response range of rock and the working area of loads and increase the intensity of rock vibration.When the excitation frequency is the same as or is close to the natural frequency of rock,the rock will be resonant and the vibration displacement is the largest.Effects of field applications show that:the average of drilling rate of high-frequency low-amplitude axial impact tool is 3 m/h.It is increased of 67.65％ compared with conventional drilling tools.
展开▼
