A kind of enhanced pulse pdc drill bit for drilling

Abstract

The invention relates to an improved pulse PDC bit for well drilling. The inner cavity of a bit body is provided with a water flow channel along the axis. The lower part of the water flow channel is provided with a divergence area. Pulse nozzles are uniformly installed in the lower part of the divergence area. An organ pipe structure is arranged above the divergence area. The organ pipe structure is sequentially provided, from top to bottom, with an organ pipe water inlet cavity, an organ pipe resonance cavity and an organ pipe water outlet, which are of a laddered cylindrical hole shape. The diameter of the organ pipe water inlet cavity is greater than the diameter of the water flow channel and greater than the diameter of the organ pipe resonance cavity. The diameter of the organ pipe resonance cavity is greater than the diameter of the organ pipe water outlet. The upper-end water inlet of the organ pipe water inlet cavity is communicated with the water flow channel, and the organ pipe water outlet is communicated with the center of the divergence area. Each pulse nozzle is sequentially provided with a nozzle water inlet, a nozzle disturbance area, a nozzle collision area and a nozzle separation area from top to bottom, wherein the lower end of the nozzle separation area is provided with a nozzle water inlet. By adopting the bit, the effect of well bottom cleaning and the capability of hydrodynamic rock breaking can be improved.

Description

technical field [0001] The invention relates to a drill bit for drilling, in particular to an enhanced pulse PDC drill bit for drilling, and belongs to the technical field of petroleum drilling equipment. Background technique [0002] The drill bit is the main tool for drilling and breaking rocks. Since its appearance, it has developed into different types and series for different strata and lithology. Usually, when selecting a drill bit, the engineering and geological conditions are considered, and economic benefits are taken into consideration, mainly from the following two aspects: (1) the same drill bit can obtain more footage; (2) the same time can obtain Faster ROP. The amount of footage obtained by the same drill bit is mainly related to geological conditions, drilling materials and engineering technical parameters; under certain conditions of geological conditions, drilling materials and engineering parameters, a higher ROP can be obtained at the same time, and the ...

AI Technical Summary

Problems solved by technology

[0006] 1. Combination of conventional PDC bit and ordinary nozzle, when the drilling fluid flows out of the nozzle after passing through the water hole in the drilling tool and the inner cavity of the drill bit, since the fluid has not been disturbed, a continuous jet is produced at the bottom of the well. Although this continuous jet is to a certain extent It is helpful for hydraulic rock breaking and cleaning of the bottom of the well, but the degree of tumbling and migration of cuttings is limited, and it is easy to cause repeated cutting; the continuous jet also produces a relative positive pressure field at the bottom of the well, which has a certain impact on the rock at the bottom of the well. Suppression, which limits the increase in ROP

[0007] 2. When the pulsed cavitation jet tool is used to cooperate with the drill bit, the length of the tool itself plus the height of the drill bit usually causes cavitation to occur about 0.5m away from the nozzle. The effective spray distance of any cavitation jet is certain. If the effective spray distance If it is less than the distance between the cavitation occurrence location and the water hole of the drill bit, the pulse jet generated at the nozzle will be weakened, and the effect of hydraulic rock breaking and bottom hole cleaning will also be weakened, and the degree of increasing the ROP will be limited

[0008] 3. Since the design of the pulse nozzle is limited by the size of the drill bit water hole and its own strength requirements, the pulse effect generated cannot be maximized. In addition, after the depth of the well, as the bottom hole confining pressure increases, the performance of the pulse nozzle will also be weakened. The actual effect, which makes the effect of hydraulic rock breaking and cleaning the bottom of the well is weakened, and the degree of increasing the ROP is also limited

[0009] 4. One of the principles of drilling safety is to simplify drilling tools as much as possible, that is, the joints in the drilling tool assembly should be as few as possible. When using pulse cavitation jet joints, it will increase the hidden safety hazard in the well; in addition, the single-bend screw is now vigorously promoted Continuous steerable drilling technology, when it is necessary to control and adjust the well trajectory, due to the access of the pulse cavitation jet joint, it increases the difficulty of engineering control and adjustment of the well trajectory

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