Working Principle and Characteristics of PDC Bit
what is a pdc bit? PDC bit is the abbreviation of Polycrystalline diamond compact bit, also known as polycrystalline diamond cutting block bit or composite chip bit. Because of its advantages of fast drilling speed, long service life and high footage, PDC bits are widely used in oil drilling.
Structure Characteristics of Drilling PDC Bits
PDC bit is composed of the a bit body, PDC cutting teeth and a nozzle. According to different structures and drill bit manufacturing processes, the drilling PDC bits are divided into two series: steel body and matrix body.
The whole bit body of rigid drilling PDC bit is made of medium carbon steel and formed by the machine manufacturing process. Drill holes on the working face of the bit, and fix PDC cutting teeth on the bit crown by pressing in and tight-fitting. The crown of a drill bit is treated by a surface hardening process (spraying tungsten carbide wear-resistant layer, carburizing, etc.) to enhance its erosion resistance. The main advantage of this kind of drilling PDC bit is a simple pdc bit manufacturing process, but the disadvantage is that the bit body is not erosion resistant and the cutting teeth are difficult to be fixed, so it is seldom used at present.
The upper part of the drilling PDC bit is made of steel and the lower part is made of WC wear-resistant alloy. The PDC bit is made by powder metallurgy sintering process. The PDC cutting teeth are welded on the preformed groove of the carcass with low-temperature solder. Tungsten carbide matrix has high hardness and erosion resistance, so the matrix PDC bit has long service life and high footage, which is widely used at present.
Working Principle of PDC Drilling Bits
Drilling PDC drilling bit breaks rocks by cutting. The self-sharpening cutting teeth can easily cut into the formation under the action of WOB and move the shear rock forward under the action of torque. When multiple PDC cutting teeth work at the same time, and there are many free faces of the bottom rock, the rock is easy to be broken under the shear action. That’s way PDC drilling bit has higher rock-breaking efficiency ans faster drilling speed.
Correct Use of PDC Rock Bits
Diamond PDC bit has the best effect in large homogeneous soft to medium-hard formation. It is not suitable for drilling gravel layer and soft hard cross formation.
Before the PDC rock bit is put into the well, the bottom of the well shall be clean to ensure that there is no metal falls.
When the PDC rock bit is just put into the well, it should adopt small bit pressure and low rotation speed to run, andresume normal drilling until the bottom of the well is formed.
PDC drilling bit is an integral bit without any moving parts, suitable for high-speed turbo drilling.
Drilling PDC bits produced by Great Drill Bit, a leading pdc cutter manufacturer, are featuring good drilling effects like low WOB, high rotation speed and large displacement.