Special tooth PDC drill bit

Abstract

The invention provides a special tooth PDC drill bit, belongs to rotary drilling drill bits for petroleum and geology, and particularly relates to a drill bit of a special tooth special structure. Thespecial tooth PDC drill bit comprises a drill bit body and a connector. The drill bit body is composed of multiple knife wings and a gage. PDC special teeth are further brazed on the knife wings, diamond layers are arranged on base bodies of the PDC special teeth, and the diamond layers are vertical to respective normal directions. The diamond layers are provided with front bulging ridges, rear bulging ridges and sharp corners. The special tooth PDC drill bit has the advantages that the diamond layers of the PDC special teeth are vertical to the respective normal directions, all the diamond layers can participate in cutting, the drill bit has higher grinding resistance, and the service life of the drill bit is prolonged. The force bearing mode of the diamond layers is changed, the axial impact resistance of the drill bit can be improved in multiples, and the possibility that the drill bit is damaged by bit bouncing and percussion drilling is reduced.

Description

technical field [0001] The invention belongs to a rotary drilling bit for petroleum and geology, in particular to a bit with a special structure of special-shaped teeth. Background technique [0002] At present, in drilling operations in fields such as petroleum and geological exploration, rotary drilling bits using PDC teeth as cutting teeth (PDC bits for short) are widely used. The PDC bit has the advantages of high ROP and long drilling life. However, there are also the following problems: 1. In the drilling of plastic mudstone and shale formations, the formation has strong plasticity, and the popular name is "rubber formation". Neither conventional PDC bits nor roller cone bits can effectively overcome this formation. , there is a situation that the mechanical drilling speed is extremely low, or even completely immobile, which is currently a major difficulty. 2. In the drilling of extremely abrasive quartz sandstone formations, only 30-40% of the PDC teeth on the conve...

AI Technical Summary

Problems solved by technology

But there are also the following problems: 1. In the drilling of plastic mudstone and shale formations, the formations have strong plasticity, and the popular name is "rubber formations". Neither conventional PDC bits nor roller cone bits can effectively overcome this formation. , there is a situation where the ROP is extremely low, or even can’t move at all, which is currently a major difficulty

2. In the drilling of extremely abrasive quartz sandstone formations, only 30-40% of the PDC teeth on the conventional PDC bit and the diamond layer can participate in the cutting of the formation, resulting in a single PDC bit with less footage and multiple trips. Affect the drilling cycle and increase the drilling cost

At present, impregnated drill bits are generally used for drilling in extremely abrasive quartz sandstone formations. The use of impregnated drill bits requires the use of turbodrilling tools. Since turbodrilling tools require mud with low solid content, conventional mud cannot meet the requirements and must be used. Replace the mud system, which will greatly increase the drilling cost

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