【作者】 谢晓红；

【导师】 张绍和；

【作者基本信息】 中南大学 ， 地质工程， 2011， 硕士

【摘要】 本文针对如何降低PDC取芯钻头切削齿在钻进岩层时的磨损,在理论分析的基础上,利用复合片在立式车床上磨削岩样的方法模拟PDC取芯钻头切削岩石,对PDC取芯钻头的切削角、出露量、平均线速度和岩石压入硬度对复合片切削齿磨损规律的影响进行了研究。试验设定了六组不同的切削角、五组不同的出露量、五组不同的平均线速度以及五组不同岩样,在正压力和磨削路程不变的情况下,分别测得各个条件下复合片体积磨损量的变化规律。采用ANSYS有限元分析软件对钻头切削角在钻进时的应力分布做了进一步分析,并通过现场试验对前期的研究成果进行了可行性验证。本课题得到的主要结论有：(1)为了最大限度地降低复合片切削齿的体积磨损量,当切削角为10°和15°时,其最佳出露量为2.00mm；当切削角为20°25°和30°时,最佳出露量为3.00mm;而5°的切削角是不可取的；(2)为了最大限度地降低复合片切削齿的体积磨损量,当出露量为1.50mm时,切削角应选用10°；出露量为2.00mm时,切削角选择10°-15°之间的数值；出露量为2.50mm时,切削角应选择20°；出露量为3.00mm和3.50mm时,切削角应设计为30°；(3)复合片切削齿的体积磨损量在钻进时与平均线速度成正比：(4)复合片切削齿的体积磨损量与岩石压入硬度成反比；(5)压入硬度大的岩石,适宜采用较大的切削角,而压入硬度小的岩石,适宜较小的切削角；(6)切削齿受力点的有效应力随切削角的减小而增大。更多还原

【Abstract】 In order to decrease cutter’s abrasion of PDC coring bit, PDC (Polycrystalline diamond compact) was used to abrade rock in the lathe as PDC coring bit cutting rock on the academic analysis. By the experiment, the effect on PDC cutter’s abrasion rule where the cutting angle, the height of protrusion, the linear velocity and rock’s indentation hardness were made was researched. Under the same stress, same rub distance, five different groups of cutting angle, six different groups of height of protrusion, five different groups of linear velocity and five different kinds of rock, PDC cutter’s abrasion volumes were measured respectively. The Finite Element Method software ANSYS was used to analyze stress distribution in rock. And the results were all verified by the field experiment.The main conclusion is that:(1) In order to decrease the PDC cutter’s abrasion volume as far as possible, when the cutting angle of PDC coring bit is 10°or 15°, 2.00mm is the optimal height of protrusion. When the cutting angle is 20°,25°or 30°,3.00mm is the optimal height of protrusion. And 5°is not recommended to be the cutting angle.(2) In order to decrease the PDC cutter’s abrasion volume as far as possible, the cutting angle should be designed to be 10°, when the height protrusion is 1.50mm; the cutting angle should be designed to be between 10°～15°, when the height protrusion is 2.00mm; the cutting angle should be designed to be 20°, when the height protrusion is 2.50mm;and the cutting angle should be designed to be 30°, when the height protrusion is 3.00mm or 3.50mm.(3) The PDC cutter’s abrasion volume and the linear velocity are in direct proportion during drilling.(4) The PDC cutter’s abrasion volume is in inverse proportion to indentation hardness.(5) When the indentation hardness of rocks is larger, bigger cutting angle of PDC coring bit should be designed.(6) When the cutting angle is enlarged, the effective-stress of cutter will be decreased.更多还原