Development of Multi-stage High Matrix Diamond Coring Bit

An important way to improve overall drilling efficiency is to crease each bit's life and footage,, high matrix diamond coring bits are especially used in deep hole. In this paper, the brazing process of designing and manufacturing high matrix diamond coring bit was introduced. Firstly, impregnated diamond blocks were manufactured using hot pressing method; secondly, new drill bit steel body including waterway was processed; in the end, the impregnated diamond blocks was welded on the new drill bit steel body using brazing process. Using brazing process, a φ75/54.5 two-stage high matrix diamond coring bit was developed, its work layer is 15 mm, the experimental results showed that the drilling efficiency increased, and the bit life improved over 50% comparing with the conventional impregnated diamond coring bit. And then, a φ75/54.5 three-stage high matrix diamond coring bit was developed, its work layer is 22 mm, and the bit life improved over 120%.