孕镶金刚石钻头的局部体积破碎研究

Study on local volume breakage of diamond-impregnated bit

针对孕镶金刚石钻头在坚硬岩石中的低钻速、高能耗问题,提出以体积破碎的碎岩方式来提高钻进效率的方法。为了进一步探究孕镶金刚石钻头的体积破碎形式,首先设计了单颗金刚石压入岩石全过程的室内实验。通过分析试验数据发现,金刚石压入岩石发生首次局部体积破碎即为金刚石钻头的体积破碎类型。然后,建立了金刚石压入岩石发生首次体积破碎时钻头的钻压和钻速计算模型,并通过对比理论值和实际值,进一步验证了单颗金刚石压入岩石试验结果以及计算模型的正确性。最后,通过分析计算结果,提出了在小粒径金刚石钻头中添加大颗粒金刚石来实现部分体积破碎的方法,并推导出钻头中应添加大颗粒金刚石的制品浓度,确定了大小粒径金刚石的添加量,并对大颗粒金刚石在钻头中的分布情况以及碎岩方式进行了探讨,可为实际中钻头参数设计提供参考依据。

To solve the problem of high energy consumption and slow drilling speed of impregnated diamond drill in hard rock,the method of volume crushing to improve drilling efficiency was put forward.In order to study the crushed volume of impregnated diamond bit in hard rock,firstly,an test of single diamond pressed into rock was designed.According to the experimental data,the first partial broken volume when single diamond was pressed into rock was the volume breakage type of impregnated diamond bit.Then the mathematical model of optimal drilling pressure and speed in first partial broken volume was deduced.By comparing the theoretical value with the actual value,the results of test of single diamond pressed into rock and the correctness of mathematical model were further verified.Finally,we put forward a method to improve drilling speed,the method is to add large-grained diamond to small-grained diamond bit,to quantitatively calculate the theoretical concentration of large-grained diamond,and the addition amount of small and large diamond grain was determined,the distribution and rock crushing ways of large diamond was discussed,which will provide reference for parameter design of diamond-impregnated bit.