Mixed drilling bit with enhanced core part cutting function

Abstract

The invention relates to a mixed drilling bit with an enhanced core part cutting function used for petroleum, natural gas and geology drilling. The mixed drilling bit comprises a drilling bit body, wherein cutter wings and a spray nozzle are arranged on the drilling bit body, the outline of the cutter wings is divided into a core part, an inner cone, a nose part, a shoulder part and a diameter maintaining part from inside to outside, fixed cutting teeth are arranged at the inner cone, the nose part, the shoulder part and the diameter maintaining part of the outline of the cutter wings on the cutter wings, a tooth palm is arranged between the cutter wings, the upper end of the tooth palm is connected into a whole with the drill bit body, the lower end of the tooth palm is provided with a tooth wheel, and tooth wheel cutting teeth are arranged on the tooth wheel. The mixed drilling bit is characterized in that the core part of the lower end of the drilling bit body is provided with the movable cutting teeth. The mixed drilling bit has strong integral performance, and shaft bottom rock can be effectively subjected to pre-crushing, so the fixed cutting teeth of the drilling bit can effectively enter the rock, in addition, the impact on the fixed cutting teeth can be reduced, the cutting efficiency and the mechanical drilling speed of the core part of the drilling bit can be respectively improved and accelerated, and the integral cutting efficiency and the mechanical drilling speed can be respectively improved and accelerated.

Description

technical field [0001] The invention relates to a hybrid drill bit with enhanced core cutting function for petroleum, natural gas and geological 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 fixed cutting teeth on the nose and shoulder of the diamond bit are difficult to effectively enter the well The drilling speed of the diamond drill bit will become very slow if the bottom rock is used; 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. Therefore, the cutting efficiency of the cutting teeth of the roller cone bit is also very low. On the other hand, when the drill bit encounters some formatio...

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 fixed cutting teeth on the nose and shoulder of the diamond bit are difficult to effectively enter the well The drilling speed of the diamond drill bit will become very slow if the bottom rock is used; 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. Therefore, the cutting efficiency of the cutting teeth of the roller cone bit is also very low

On the other hand, when the drill bit encounters some formations with more soft and hard interlayers, the fixed cutting teeth of the PDC diamond drill bit are extremely vulnerable to impact damage. In order to deal with this situation, Chinese patent document CN200880016630. A hybrid drill bit composed of PDC diamond 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 rotation of the cone is easy to cause The fixed cutting tooth composite sheet of the drill bit is broken, resulting in a reduction in the drilling speed of the drill bit, and the fixed cutting tooth is the closest to the axial center of the drill bit on the drill bit. Since the fixed cutting tooth is too close to the axial center of the drill bit, the radius of gyration is small. The cutting speed is low, so the cutting efficiency is low; and the fixed cutting tooth speed alone cuts the axial center rock at the bottom of the well, which bears a large load, and the composite layer is prone to fracture or fall off

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