Research of diamond weak combined bit for high geo-stress stratum drilling;

Research into the new electroplating weak-holding diamond bits;

Research,development and application of the series core drilling bit for uranium exploration;

Research of the Edge Grinding with the Simplified Conical Drill;

Dynamic Model of Drill during Vibrational Drilling;

A Forecasting System for Wear of Drill;

Geared hydraulic motor design for drill bit of rotary well wall coring utensil;

Investigation in the direction controlling system of drill bit on horizontal auger;

The quantitative calculation of the forces between drill bit and formation is vital for drilling trajectory control.

In this paper,by testing and analyzing,it is showed that the performance of drill bits are influenced by various factors in the hot pressure sintering process of intermediate-frequency furnace.

CAD/CAM technique in PDC drilling bits female mould processing base on Pro/E;

, drilling parameters reasonably matched well, polymer clay free drilling fluid injected-time prolonged, drilling bit types .

Geometrical optics approach can only calculate the high frequency approach solution of drilling bit vibration source wave equation in non caustic area but it become invalid in caustic area.