基于数字钻孔的钻头磨损与随钻参数关系研究

Research on the Relationship Between Bit Wear and Drilling Parameters Based on Digital Drilling

通过随钻参数反演岩石力学参数是数字钻孔技术的核心问题,PDC钻头是数字钻孔技术中破岩的主要结构。为了分析PDC钻头磨损程度对随钻参数的影响,基于煤矿液压锚杆钻机建立了数字钻进系统。利用该系统进行了钻头不同磨损程度下的数字钻进试验,同时结合有限元软件对钻进过程进行模拟,研究了PDC钻头磨损条件下随钻参数的变化规律。研究结果表明:钻进过程中各随钻参数之间的相关性与岩石强度变化规律显著;随钻参数对钻头磨损程度响应明显,在相同动力以及岩石强度条件下,钻进速度随着钻头磨损程度的增大而减小,钻杆扭矩随磨损程度增加而增大。试验结果与数值计算结果变化规律一致,证明了钻头不同磨损程度对于数字钻孔技术确定岩石性质具有重要影响。该研究为PDC钻头在数字钻孔中合理调整钻进参数以及反演岩石力学参数提供了参考。

The inversion of rock mechanics parameters by drilling parameters is the core issue of digital drilling technology,and PDC bit is the main structure for rock breaking in digital drilling technology.In order to analyze the influence of PDC bit's wear degree on drilling parameters,a digital drilling system was established based on coal mine hydraulic anchor drilling rig.The system was used to carry out digital drilling tests under different wear degrees of the bits.At the same time,the drilling process was simulated by finite element software,and the variation law of driing parameters under PDC bit's wear conditions was studied.The results show that the correlation among the drilling parameters and the variation of rock strength are significant.The drilling parameters have obvious response to the wear degree of the bit.Under the same dynamic and rock strength conditions,the drilling speed decreases with the increase of the wear degree of the bit,and the torque of the drill pipe increases with the increase of the wear degree.The experimental results are consistent with the numerical calculation results,which proves that the different wear degrees of the bits have an important influence on the determination of rock properties by digital dilling technology.This study provides a reference for PDC bit to reasonably adjust drlling parameters and invert rock mechanics parameters in digital drilling.