热力复合作用下PDC钻头动态磨损机理与引磨力平衡布齿理论研究

PDC bit is the main rock-breaking tool in oil and gas drilling field. However, when drilling in high temperature and hard formation, PDC bit wears out obviously and the phenomenon of force imbalance is prominent, which leads to rapid failure of the PDC bit, great decrease in drilling efficiency. This seriously affects the progress of drilling exploration and development. As an effective method to improve drilling performance of bit, force-balanced cutter layout technology has not considered wear factor. In view of the fact that the effect of bit wear on force-balanced characteristics in high temperature environment is not clear yet, and the interaction between wear and cutting force is difficult to describe scientifically, this project starts from three aspects: single cutter wear mechanism under the coaction of heat and force, dynamic wear mechanism of PDC bit, and guided-wear cutter layout theory for maintaining real-time force balanced. Dynamic wear mechanism of PDC bit and guided-wear force balanced cutter layout theory under the coaction of heat and force is systematically studied by the combining method of theoretical analysis, experimental analysis and verification. This study will form the basic theory and method of guided-wear force balanced cutter layout, which can solve the problem of force imbalance caused by wear, prolong the service life of drill bit, improve drilling stability and efficiency, and provide theoretical and experimental support for the application of PDC bit in high temperature hard rock. The research results of this project will have broad application prospects in bit life prediction, cutter layout design and geothermal bit development.

PDC钻头是油气钻井领域的主要破岩利器，然而其在钻遇高温硬地层时磨损明显、由磨损引起的力不平衡现象突出，导致钻头快速失效、钻井效率大幅降低、严重影响探勘开发钻井进度。力平衡布齿设计技术作为提高钻头钻井性能的有效措施，尚未考虑磨损因素。本项目针对高温环境下钻头磨损对力平衡特性的影响规律尚不明确、磨损和切削受力相互作用关系难以科学表述等特点，从热力复合作用下单齿磨损机理、PDC钻头动态磨损机理、维持钻头实时力平衡的引磨布齿理论三方面研究入手，采用理论分析、实验分析与验证相结合的办法，系统开展热力复合作用下的PDC钻头动态磨损机理及引磨布齿理论研究。通过本研究将形成引磨力平衡布齿基本理论及方法，解决由磨损引起的力不平衡问题，延长钻头寿命，提高钻井稳定性与效率，为PDC钻头在高温硬岩中的应用提供理论和实验支撑。本项目研究成果将在钻头寿命预测、布齿设计、地热钻头研制等方面有广泛应用前景。

PDC钻头是油气钻井领域的主要破岩利器，然而其在钻遇高温硬地层时磨损明显、由磨损引起的力不平衡现象突出，导致钻头快速失效、钻井效率大幅降低、严重影响探勘开发钻井进度。力平衡布齿设计技术作为提高钻头钻井性能的有效措施，尚未考虑磨损因素。本项目针对高温环境下钻头磨损对力平衡特性的影响规律尚不明确、磨损和切削受力相互作用关系难以科学表述等特点，从热力复合作用下单齿磨损机理、PDC钻头动态磨损机理、维持钻头实时力平衡的引磨布齿理论三方面研究入手，采用理论分析、实验分析与验证相结合的办法，系统开展热力复合作用下的PDC钻头动态磨损机理及引磨布齿理论研究。取得的重要成果具体如下：.（1）构建了考虑温度因素的单颗PDC齿线磨损模型以及切削受力模型，分析了PDC齿工作参数、结构参数、钻井参数和环境参数对PDC齿切削受力、齿体温度以及磨损速率的影响规律，找到了影响PDC齿磨损的主要因素，揭示了PDC齿在温度载荷作用下的磨损机理。.（2）分析了PDC钻头上相互关联破岩、相互关联受力、相互关联磨损的各切削齿的磨损趋势，得到了PDC钻头齿的磨损规律及特征。.（3）构建了PDC钻头的钻压、扭矩、侧向力和弯曲力矩模型，分析并获得了磨损对PDC钻头切削受力的影响规律。.（4）构建了PDC钻头力平衡布齿优化设计模型，提出模型求解方法和布齿方案，形成了考虑温度和载荷影响的PDC钻头力平衡布齿优化方法。.（5）依托项目研究，发表高水平论文7篇，其中SCI 4篇；授权专利2件，其中发明专利1件。培养硕士研究生3人。.通过本研究形成了考虑温度和磨损因素的PDC钻头力平衡布齿基本理论及方法，解决了由磨损引起的力不平衡问题，这对延长钻头寿命，提高钻井稳定性与效率具有重要意义。