Blade type PDC (Polycrystalline Diamond Compact) drill bit

Abstract

The invention discloses a blade type PDC (Polycrystalline Diamond Compact) drill bit, comprising blades, PDC cutting teeth, nozzles, chip grooves, a drill bit diameter-maintaining part and a drill bit body, wherein the blades are fixed on the crown head of the drill bit body; the blades includes main blades and short blades, which are uniformly distributed at intervals; the tail ends of the three main blades extend to be connected with one another and supported mutually; the distances of the short blades of a 8.5'' drill bit from the drill bit center respectively are 45 mm, 55 mm and 65 mm; the back of each blade forms an inclination of 8-12 degrees with the central line of the crown head of the drill bit body; the thickness of each blade is gradually increased along with the distance between the blades and the cutting edge; the tail part of each blade is of the shape of a parabola; PDC cutting teeth are arranged on the blades; the chip grooves are arranged between adjacent blades; and the fixed nozzles and the adjustable nozzles are inlaid on the drill bit body. According to the drill bit, the shape of the main blades and the distribution of the nozzles and water holes are adjusted based on the traditional drill bit structure, therefore, the diameter of the drill bit can be better prevented from being worn, the forming of drill bit bouncing and drill bit balling can be avoided, the service life of the drill bit can be prolonged so that the well building period can be shortened. The blade type PDC drill bit is also applicable to drilling ultra deep wells and wells in complex conditions for oil and natural gas.

Description

technical field [0001] The invention relates to a drilling tool in the coal bed gas drilling process, in particular to a blade-type PDC drill bit suitable for medium-hard and hard blocks. Background technique [0002] The geological structure of coalbed methane blocks is complex, with staggered formation layers, mixed soft and hard, and gravel in some blocks, resulting in rapid wear and tear of drill bits. For many years, coalbed methane development drilling has been drilled with three-cone bits, but the three-cone bits are not wear-resistant, and the cutting time is slow; conventional PDC bits, including six-blade PDC bits, are inlaid with cylindrical polycrystalline Diamond composite sheet, because each blade is separated independently, it is very easy to break and wear quickly. During the drilling process, due to formation changes and drill bit reasons, it is often necessary to pull out the drill midway and replace the drill bit, which not only increases the labor intens...

AI Technical Summary

Problems solved by technology

[0003] In view of the problems existing in the above-mentioned prior art, the present invention provides a blade-type PDC drill bit, which optimizes the geometric shape of the existing six-blade PDC drill bit blade and the water hole of the drill bit, and can solve complex and large formation changes. The rock is hard, the drill bit is easy to wear, and the drilling speed is slow. This drill bit has a wide range of applications and high overall efficiency.

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