组合切削具产生的预破碎区对钻进效果的影响

Influence of Pre-break Zone Generated by the Combination of Cutting Tools to Drilling Effect

从组合切削具将在岩石中产生预破碎区的论点出发,通过实验定量研究了预破碎区深度与掏槽刃切入深度的关系,得出了预破碎区有利于降低岩石强度及岩石破碎能耗的结论,并用生产试验结果进行了验证。提出了孕镶金刚石钻头钻进Ⅶ～Ⅷ级硬岩时仍存在预破碎区和切削、微切削破岩方式,以及预破碎区并非越大越好的学术观点。

Based on the view that the combination of cutting tools can produce pre-break zone in rock,this paper quantitatively studies the relationship between the depth of pre-break zone and the cut depth of cutting edge.The results show that the pre-break zone can contribute to reduce rock strength and rock fragmentation energy,which is also verified by the field test results.It gets the following two academic views： there are still pre-break zone,cutting and micro-cutting rock breaking modes when drilling Ⅶ～Ⅷ-class hard rock with the impregnated diamond bit;the view ＂the bigger of pre-break zone,the better of drilling effect＂ is not correct.