岩层钻孔过程中切削模型及影响因素分析

针对岩层钻孔过程中钻孔效率较低,以及获取地层应力较困难等问题,将钻孔过程分解为轴向压入岩体和转动切削岩体2个环节,分析了切削刃转动切削岩体的静力学关系,建立了切削刃切削力与岩体抗力之间的关系,构建了转动切削静力学模型,获得了切削深度、切削刃形状、岩体力学性质对切削力影响规律。研究结果表明:切削深度与切削力呈线性关系,切削深度越大则切削岩体切削力越大;切削力随切削刃角度的增大呈先增大后减小的变化趋势;岩石黏聚力、内摩擦角与切削力呈线性关系,黏聚力、内摩擦角越大则所需切削力越大。

Analysis of cutting model and influencing factors in the process of rock formation drilling

In view of the low drilling efficiency and the difficulty in obtaining formation stress during the drilling process of rock formation,the drilling process was decomposed into two steps:axial compression into rock mass and rotational cutting rock mass,the static relationship of cutting rock mass rotary cut by cutting edge was analyzed,the static model of rotational cutting was constructed.The influence law of cutting depth,cutting edge shape and rock mass mechanical property on cutting force was obtained.The results show that there is a linear relationship between cutting depth and cutting force,the greater the cutting depth,the greater the cutting force;the cutting force increases first and then decreases with the increase of cutting edge angle;rock cohesion,internal friction angle is linear with the cutting force,the greater the cohesion and internal friction angle,the greater the cutting force required.