用于煤系软硬互层新型PDC取心钻头的设计与应用

Design and Application of New PDC Bit in Coal-measures Soft and Hard Interbeded Formation

摘要:

PDC（Polycrystalline Diamond Compact）钻头适用于软到中硬的均质地层钻进，具有钻速高、寿命长等特点，但不适合软硬互层等地层。鉴于此，针对煤系软硬交错地层（3～8级）钻进效率低、钻头寿命短和岩心采取率低的特点，提出了加强保径结构、改善水路循环和超前辅助切削齿的设计。设计制造的φ77 mm PDC取心钻头在重庆市綦江县同华煤矿勘探3号孔钻进中取得了较好的使用效果。

Abstract:

PDC bit is applicable to drill in soft to medium-hard homogeneous layer with high ROP and long service life, but not suitable for drilling in gravel and multi-interbedded formation. According to the problems of low efficient, short service life and low core recovery in coal-measures soft and hard multi-interbeded formation(3~8 degree), the paper put forward a design with strengthening radius retention structure, improving the water circulation and advancing auxiliary cutting teeth. φ77mm PDC bit was designed and manufactured, and good application effect was achieved in the exploration borehole No.3 of Tonghua coal mine in Qijiang County of Chongqing.