斧形PDC齿破岩规律数值模拟研究

斧形PDC齿具有独特的齿形,在破岩实验中表现出更好的破岩性能。但斧形PDC齿破岩规律和工作参数及齿形的优选方法不明确。因此,利用ABAQUS软件建立了斧形PDC齿切削岩石的三维有限元模型,通过有限元数值模拟方法分析后倾角、斧刃角对斧形PDC齿破岩效果的影响。结果表明:后倾角为15 °时,斧形PDC齿破岩效率最高;在后倾角相同的情况下,斧刃角越小,切向裂纹越易于向岩石内部发展,最优斧刃角为110 °。根据模拟结果,优化了斧形PDC齿钻头外形参数,并在现场试验中获得较好的效果。该研究结果可为斧形PDC齿钻头优化设计提供重要依据。

Study on Rock Breaking Rules of Axe-shaped PDC Cutter with Numerical Simulation

Axe-shaped PDC cutter is of special shape and presents better breaking performance in rock breaking experiment. However, the rock breaking rules of axe-shaped PDC cutter and the optimization method of its working parameters and shape are ambiguous. Therefore, a three-dimensional finite element model of cutting rock with axe-shaped PDC cutter was established with ABAQUS software, and the effects of back dip angle and axe edge angle on the rock breaking effect of axe-shaped PDC cutter were analyzed by finite element numerical simulation method. The results showed that the rock breaking efficiency of the axe-shaped PDC cutter was the highest when the back dip angle was 15 °; with the same back dip angle, the smaller the axe edge angle was, the easier the tangential crack was to propagate inside the rock, and the optimal axe edge angle was 110 °. According to the simulation results, the shape parameters of the bit with axe-shaped PDC cutter were optimized, and good results were obtained in the field test. The results of the study provide an important basis for the optimal design of the bit with axe-shaped PDC cutter.