深部钻探极端环境下金刚石钻头工作特性与失效机制研究进展与展望

Research progress and prospects on working characteristics and failure mechanisms of diamond drill bits under extreme environments in deep drilling

摘要:

金刚石钻头在深部钻探高温、高压、高研磨、强腐蚀及多场耦合极端环境下的工作性能面临严峻挑战。本文系统梳理了PDC钻头与孕镶金刚石钻头在上述环境下的工作特性与失效机制。结果表明：高温环境下PDC钻头以热损伤与界面剥离为主，孕镶金刚石钻头表现为胎体软化和金刚石热损伤；高压环境下PDC钻头易发生切削齿断裂与分层剥离，孕镶金刚石钻头则出现胎体变形与金刚石脱落；高研磨环境下两类钻头均遭受磨粒磨损与振动疲劳的协同失效；腐蚀环境下PDC钻头发生化学溶解与微电偶腐蚀，孕镶金刚石钻头以黏结相选择性溶蚀为主，腐蚀?磨损协同作用显著加速材料流失；多场耦合使各损伤机制相互促进，产生非线性放大效应。相应地，分别可通过水力结构优化与耐热材料改性、异形齿与射流辅助、仿生结构与超耐磨胎体、组分优化与表面涂层、梯度结构设计等来延长钻头寿命或提高破岩效率。未来应重点深化多场耦合机理研究、推进极端环境专用材料的工程验证、发展智能钻头技术，支撑深部极端环境钻探技术的迭代升级。

Abstract:

The working performance of diamond drill bits faces severe challenges under extreme deep-drilling environments characterized by high temperature， high pressure， high abrasiveness， strong corrosion， and multi-field coupling. This paper systematically reviews the working characteristics and failure mechanisms of PDC bits and impregnated diamond bits under the aforementioned environments. The results indicate that： under high-temperature conditions， PDC bits primarily suffer from thermal damage and interfacial delamination， while impregnated bits exhibit matrix softening and thermal damage to diamond； under high-pressure conditions， PDC bits are prone to cutter fracture and delamination， whereas impregnated bits undergo matrix deformation and diamond particle shedding； under highly abrasive conditions， both types of bits experience synergistic failure caused by abrasive wear and vibration fatigue； under corrosive conditions， PDC bits undergo chemical dissolution and micro-galvanic corrosion， whereas impregnated bits mainly exhibit selective dissolution of the binder phase， and the corrosion-wear synergy significantly accelerates material loss； multi-field coupling promotes mutual reinforcement among various damage mechanisms， producing a nonlinear amplification effect. Correspondingly， the service life of drill bits can be extended or the rock-breaking efficiency can be improved through hydraulic structure optimization and heat-resistant material modification， shaped cutters with jet assistance， bionic structures and ultra-wear-resistant matrices， composition optimization and surface coating， as well as gradient structure design. Future research should focus on deepening the research on multi-field coupling mechanisms， promoting the engineering validation of extreme-environment-specific materials， and developing intelligent drill bit technologies， thereby supporting the iterative upgrades of drilling technologies for extreme deep-earth environments.