Multi-jetflow bodied tricone bit

Abstract

The invention relates to a multi-jetflow bodied tricone bit. The multi-jetflow bodied tricone bit comprises a drill bit body, three cone palms and three cones. A drill bit handle is arranged at the top of the drill bit body, the middle of the drill bit body is provided with an inner flow passage, three side nozzles are peripherally arranged on the lower portion of the drill bit body and communicated with the inner flow passage, and lower portions of the cone palms are provided with journals with the cones. The multi-jetflow bodied tricone bit is characterized in that a central nozzle seat is arranged at the lower end of the middle of the drill bit body, a central nozzle is mounted in the middle of the lower end of the central nozzle seat, three middle nozzles are arranged at the lower end of the central nozzle seat surrounding the outer periphery of the central nozzle, and the central nozzle and the middle nozzles are communicated with the inner flow passage through a cavity. The multi-jetflow bodied tricone bit has the advantages that drilling fluid can be jetted to a mesh gap between each two adjacent cones, so that turbulence velocity and crossflow velocity of the drilling fluid at the bottom of a well can be increased to enable rock debris to be quickly taken away from the bottom of the well; the cones can be cleaned more uniformly to effectively avoid bit balling of the tricone bit, and accordingly increase of mechanical drilling rate of the bit and reduction of drilling cost are realized.

Description

technical field [0001] The invention relates to a body type tricone drill bit used for oil, natural gas, geology, mine, hydrology and geothermal resource drilling, in particular to a multi-jet body type tricone bit using drilling fluid as a circulating medium. technical background [0002] According to the actual needs of drilling engineering, the diameter of the earth-drilling tri-cone bit is generally 98.425mm (37 / 8") ~ 914.4mm (36"). The tri-cone bits of each diameter are divided into dozens of different models to meet the needs of different formations and different drilling techniques. [0003] Existing earth-boring roller cone bits usually include three palms 2 and three roller cones 4, also known as tri-cone bits. Processed three holes on the drill bit, are used for installing side nozzle 9. A supporting journal 7 is provided on the tooth palm 2, and an inner hole whose center line is coaxial with the conical rotary body is provided on the cone, and a cone 4 is insta...

AI Technical Summary

Problems solved by technology

The obvious disadvantage of this invention is: due to the space limitation of the tooth palm, the hole for installing the intermediate nozzle 10 can only be located below the journal, that is, the intermediate nozzle 10 can only be installed under the cone

After the middle jet 13 is ejected from the middle nozzle 10, it is directly sprayed on the surface of the cone 4, which may easily cause the shell of the cone to be eroded, or cause the cutting teeth of the toothed cone bit to fall off from the cone.

[0014] Chinese Patent Application No. 91201791.0 discloses a hydraulic structure in which the lengthened side nozzle 9 cooperates with the central nozzle 11. The risk of the lengthened side nozzle is that when the drill bit encounters a gravel layer or a large volume of rock falls from the well wall, Gravel or falling rocks are easy to crush Extended side nozzle

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