Inner-chip removal polycrystalline diamond compact (PDC) bit

Abstract

The invention provides an inner-chip removal polycrystalline diamond compact (PDC) bit, which comprises a bit body, a cutting portion and mudproof packages, wherein a connecting head is formed on the upper end of the bit body, a gauge protection portion is formed on the lower end of the bit body, an inner cone hole is formed in the bottom end of the gauge protection portion, and a chip removal cavity which is run through along the axial direction is arranged in the bit body, and is communicated with the inner cone hole. The cutting portion is connected on the bottom end of the gauge protection portion, and is provided with a plurality of spiral knife blades, and the spiral knife blades are convexly arranged on an inner cone surface of the inner cone hole along the peripheral direction. The mudproof packages are connected on the lower end of the gauge protection portion and are arranged between the every two spiral knife blades. The inner-chip removal PDC bit has an active mudproof package function, prevents forming a bit mud package during the drilling process, and meets the demands of self-buried drilling to the functions of PDC bits.

Description

technical field [0001] The invention relates to a PDC drill bit, in particular to an internal chip removal PDC drill bit used in the field of self-buried drilling. Background technique [0002] At present, a new self-burial drilling method without drilling rig, without drilling fluid, and buried while drilling is being formed. It can realize unmanned exploration and monitoring of formations in complex areas and harsh environments, saving a lot of manpower and material resources. In this new type of drilling method, since there is no drilling fluid to flush the blades of the drill bit, and cuttings are required to be sent upwards from the inside of the drill bit to the body of the drill bit, mud balls are easily formed between the blades, resulting in the termination of drilling. [0003] Existing PDC bits use the high-pressure drilling fluid ejected from the bit nozzle to carry the broken cuttings from the annular space between the drill string and the well wall to the surfa...

AI Technical Summary

Problems solved by technology

This new type of drilling method, because there is no drilling fluid to rinse the blades of the drill bit, and the cuttings are required to be sent upward from the inside of the drill bit to the drill body, so mud bags are easily formed between the blades, resulting in the termination of drilling

[0003] Existing PDC drill bits use the high-pressure drilling fluid injected from the drill bit nozzle to carry the broken cuttings from the annular space between the drill string and the well wall to the surface to achieve self-cleaning, which obviously cannot meet the functional requirements of self-burial drilling.

Due to the complex and unknown stratum conditions, the existing internal chip removal PDC bit used for self-burial drilling only has the internal chip removal function, which cannot handle the mud balls formed between the blades, which seriously affects the drilling of the PDC bit

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