PDC钻头钻进岩石破碎过程及其与钻进规程参数关系的分析研究

Analytical research on the rock fragmentation process and its relationship with drilling parameters in PDC bit drilling

摘要:

PDC复合片钻头在地质勘探和石油天然气钻井等领域得到了广泛的应用，取得了很好的技术经济效果。但是，对于其碎岩过程及其与钻进规程参数间的关系研究不够深入，影响了技术经济指标的进一步提高。俄罗斯钻探工作者在这方面做了很多工作，取得了一定效果，值得引起我们的注意。例如，他们建议，由于岩石破碎方式是变化的，所以，尽量使岩石破碎处于体积破碎状态；如果把钻头每转进尺能耗量指标作为一个评价指标考虑进去，则评价系统会更加科学和更加全面；钻头每转进尺，不是越高越好，有一个最优值，这个最优值与钻进规程参数密切相关；提出了临界钻进规程的概念，即当轴载和转速的乘积高达一定数值时，切削具温度急剧上升、钻头磨损明显加剧，冲洗液量再大也无济于事，因此，此时应该采取措施，及时调整规程参数，避免钻进过程处于临界规程状态，以便使钻进处于正常状态，继续钻进下去。

Abstract:

Drill bits with PDC（Polycrystalline Diamond Compact）are used widely in geological exploration ， oil and gas drilling and other corresponding fields and good technical， and economic results have been obtained. However， the research on the rock fragmentation process and relationship with drilling parameters in not enough and it affects the further increase of the technical and economic indexes of the PDC bits. Russian drillers have made a lot of work in this field，including the bits，and obtained definite success and it worth us pay attention to. For example， they propose that rock fragmentation should be proceeded under volumetric fragmentation state as well as possible because the rock fragmentation mode is changed； If energy consumption of penetration per revolution of bit is included as an evaluation index， the evaluation system will be more scientific and more overall； Penetration per revolution of bit is not the higher the better， it has an optimum value. The value is depended from drilling parameters closely； it is put forward an idea of critical drilling parameters， meaning that while the product of bit weight and rotary speed is more， than the product， the temperature of the bit will rise drastically， the bit will wear seriously and any large quantity of drilling fluid cannot help resolve the problems. In this case it is necessary to take measures， adjust drilling parameters and avoid drilling process being in the critical state， so that drilling is in the normal state and the drilling can be continued.