| Summary: | Bionic coupling polycrystalline diamond compact (PDC) was designed according to the biological coupling theory, its performance was evaluated by wear resistance experiment, and then the bionic coupling PDC bit was made and used in field drilling test. The design of the bionic coupling PDC was based on natural models (e.g. shell, mole cricket, human teeth, bamboo and tree annual ring) and started with materials of polycrystalline diamond and carbides, polycrystalline diamond-carbides interface and polycrystalline diamond non-smoothed surface. The wear resistance experiment results show that: the bionic coupling PDC performs higher drilling speed and better wear-resistance than the conventional PDC of the same size, the abrasion ratio is increased by 18.4% and the wheel wear rate is improved by 167%. In field drilling test, the bionic coupling PDC bit was designed according to stratum and depth and compared with the conventional PDC bit used in nearby wells. The mechanical drilling speed of the bionic coupling PDC bit is 2.5 times that of the conventional PDC bit, so the bionic coupling PDC bit can reduce drilling cycle and decrease drilling cost greatly. Key words: bionic coupling, polycrystalline diamond compact, drilling, bit
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