Hybrid drill bit

Abstract

The invention relates to a hybrid drill bit for petroleum, natural gas and geological drilling. The hybrid drill bit comprises a drill bit body, wherein a cutter wing and a roller cone are arranged on the drill bit body, cutting teeth are arranged on the cutter wing, the roller cone is connected with the drill bit body through a cone leg, and the hybrid drill bit is characterized in that the roller cone is a disk type roller cone. A cutting element on the disk type roller cone is shaped like a disk cutter or an intermittent disk cutter. The patent disclosed by the invention has the beneficial effects that, 1) the scraping motion of a diamond drill bit and the rolling motion of a disk type roller cone drill bit are combined for realizing precrushing at the bottom of a well, thereby ensuring that the diamond cutting teeth can effectively bite rock, eliminating the stick-slip phenomenon of the drill bit in some special formations and the probability of impact disrepair of a polycrystalline diamond compact (PDC) and improving the cutting efficiency and the mechanical drilling speed of the drill bit; and 2) the disk type roller cone can realize the precrushing of a rock layer at the bottom of the well more steadily, reduce the impact on the PDC, enhance the stability in drilling of the drill bit and enable the drill bit to realize faster and more stable drilling.

Description

technical field [0001] The patent of the present invention relates to a hybrid drill bit for oil, natural gas and geological well drilling, which is suitable for drilling in hard formations and interlayer formations. Background technique [0002] In the prior art, when the drilling encounters a hard formation, the commonly used PDC diamond bit mainly realizes downhole drilling through scraping movement, and the main cutting elements on the nose and shoulder of the diamond bit are difficult to effectively eat into the bottom of the well For rocks, the ROP of the diamond drill bit will become very slow; while the roller cone bit breaks the rock by impact crushing, which is easy to produce deep crushing tooth pits in the rock, but due to the hard formation, the rock cannot be broken by volume, so The cutting efficiency of the cutting teeth of the roller cone bit is also very low, and the drilling speed of the roller cone bit is also very slow. On the other hand, when the drill...

AI Technical Summary

Problems solved by technology

[0002] In the prior art, when the drilling encounters a hard formation, the commonly used PDC diamond bit mainly realizes downhole drilling through scraping movement, and the main cutting elements on the nose and shoulder of the diamond bit are difficult to effectively eat into the bottom of the well For rocks, the ROP of the diamond drill bit will become very slow; while the roller cone bit breaks the rock by impact crushing, which is easy to produce deep crushing tooth pits in the rock, but due to the hard formation, the rock cannot be broken by volume, so The cutting efficiency of the cutting teeth of the roller cone bit is also very low, and the drilling speed of the roller cone bit is also very slow

On the other hand, when the drill bit encounters some formations with more soft and hard interlayers, the cutting elements of the PDC diamond bit are extremely vulnerable to impact damage. In order to deal with this situation, Chinese patent document CN200880016630. A hybrid drill bit composed of diamond drill bits, although the hybrid drill bit has strong comprehensive performance, it has the following disadvantages: due to the rock-breaking mechanism of the tricone bit’s unique impact crushing, the impact load generated by the cone rotation is easy to cause the diamond The PDC composite sheet of the cutting element of the drill bit is broken, resulting in a decrease in the ROP of the drill bit

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