School of Mechanical Engineering and Electronic Information, China University of Geosciences
Faculty of Engineering, China University of Geosciences

在能源勘探与开发过程中，除了取心钻进方式之外，全面(不取心)钻进也占有较大比例。不取心钻进可以减少提钻取心所消耗的大量提下钻时间，进而增加纯钻时间、提高钻进效率和降低钻进成本。传统不取心钻头在钻探过程中容易出现钻头唇面不均衡磨损的现象，为查明和改善这种不均衡磨损规律，提出采用组合式不取心钻头改善钻头偏磨现象。首先采用数值模拟方法对一二级组合不取心孕镶金刚石钻头进行了钻进花岗岩的数值模拟分析，模拟结果显示，由钻头外缘到中心，应力值由大逐渐变小，磨损量与之相对应。在靠近水口处的钻头外缘，胎体应力值和磨损量最大，最大应力为282.14 MPa，最大磨损深度为1.1×10−5 mm。而在靠近钻头中心处，钻头胎体应力和磨损量值最小，分别为0.002 MPa和1.3×10−6 mm。在钻头唇面半径为55 mm处，钻头磨损速度出现拐点。根据数值模拟结果，设计了二级组合式不取心钻头，由外环钻头、中心钻头和相应的水路系统组成，其中外环钻头规格为ø95/48 mm，中心钻头规格为ø46/16 mm，水路系统由中心孔、4条主水路、4条副水路和环状间隙水路组成。以常钻遇的可钻性为7~8级岩石为基础，对钻头胎体配方、金刚石参数和烧结工艺进行了设计，提高外环钻头胎体耐磨性、金刚石浓度、小粒径金刚石比例，同时增大烧结温度和提高烧结压力，以降低外钻头磨损量，保证钻头内外磨损一致。采用所设计的二级组合式不取心钻头结构，试制了ø75/16 mm不取心钻头，并在可钻等级为8级的花岗岩上进行了室内钻进试验，试验结果表明，钻头磨损均匀，钻进时效约1.84 m/h，胎体消耗高度约1 mm，能满足硬岩全面钻进的需要。本研究为不取心孕镶金刚石钻头设计、研制和施工提供了借鉴。

In addition to coring drilling, full (non-coring) drilling also occupies a large proportion in the energy exploration and development. Non-coring drilling can reduce the high time cost of lifting and lowering work required for coring, thereby increasing the net drilling time, improving the drilling efficiency and reducing the drilling costs. The traditional non-coring drill bits are prone to uneven wear on the bit surface during the drilling process. To identify and improve this law of uneven wear, it was herein proposed to use the assembling non-coring bit to improve the eccentric wear of bit. For this reason, numerical simulation analysis was conducted on the drilling of granite with a combination of stage-1 and stage-2 non-coring impregnated diamond bits at first. The simulation results show that the stress and wear on the bit are decreased gradually from the outer edge to the center. Definitely, the stress and wear of bit matrix have the maximal value on the outer edge of the bit close to the water outlet, which are 282.14 MPa and 1.1×10−5 mm respectively, while the minimum value near the center of the drill bit, which are 0.002 MPa and 1.3×10−6 mm, respectively. When the radius of the bit lip is 55 mm, the bit wear speed changes. Then, a two-stage assembling non-coring drill bit was designed based on the numerical simulation results, consisting of an outer ring drill bit, a center drill bit, and a waterway system. The outer ring drill bit is in the size of ø95/48 mm, the center drill bit is sized ø46/16 mm, and the waterway system consists of a center hole, 4 main waterways, 4 auxiliary waterways and an annular gap waterway. Meanwhile, the bit matrix formula, diamond parameters and sintering process were designed based on the common drillability of 7‒8 grade rocks. To improve the wear resistance of the outer ring bit matrix, the diamond concentration, the proportion of small diamond particles, the sintering temperature and the sintering pressure were increased to a certain degree, thereby reducing the wear of the outer bit and ensuring the wearing consistency between the outer and inner bits. Besides, laboratory drilling test was carried out on the granite of grade-8 drillability with the designed ø75/16 mm two-stage assembling non-coring bit. The experiment results indicate that the bit is worn evenly, the rate of penetration is about 1.84 m/h, and the matrix consumption height is about 1 mm, which can meet the needs of full drilling in hard rocks. Generally, this research provides reference for the design, development and construction of non-coring impregnated diamond bit.

国家自然科学基金项目(42272365)

杨展，谭松成，杨凯华，等. 基于有限元分析的组合式金刚石钻头磨损规律与设计研究[J]. 煤田地质与勘探，2023，51(9)：164−170.

YANG Zhan，TAN Songcheng，YANG Kaihua，et al. Wear law and design of assembling diamond bit based on finite element analysis[J]. Coal Geology & Exploration，2023，51(9)：164−170.