Strong suction type reverse-circulation coring drill bit

Abstract

The invention discloses a strong suction type reverse-circulation coring drill bit. An internal pipe is inserted into an inner chamber of a drill bit body; an annular space is formed between the outer wall of the internal pipe and the inner wall of the inner chamber of the drill bit body; the inner chamber of the internal pipe is a center passage of the drill bit body; an inner jet hole and a bottom jet hole are formed in the sidewall of the drill bit body; an eccentric passage and a pressurization groove are formed in the bottom of the drill bit body; the inner sidewall of the lower end of the internal pipe is an arc-shaped surface; an annular nozzle is formed between the arc-shaped surface and a circular bead which is arranged at the lower end of the drill bit body. The strong suction type reverse-circulation coring drill bit disclosed by the invention has the beneficial effects of being reasonable in structural design and beneficial for improving the drilling efficiency and core (sample) exploitation rate of a down hole hammer, and having great significances for improving the reverse circulation formation effect and guaranteeing safe, rapid and efficient running of a through down hole hammer.

Description

technical field [0001] The invention relates to a reverse circulation drill bit, in particular to a powerful suction type reverse circulation core drill bit. Background technique [0002] At present, the through-type DTH hammer reverse circulation drilling technology has been successfully applied in the fields of mineral resource exploration, hydrology and water well drilling, foundation engineering construction, etc. It also has broad application prospects in oil and gas well drilling, mine emergency rescue and other fields. However, reverse circulation is difficult to form when drilling into broken and lost formations, and some gas is discharged from the annular gap in a positive circulation manner, resulting in incomplete removal of cuttings at the bottom of the hole and affecting drilling efficiency. The fine cuttings particles carried by the gas discharged by the positive circulation are easy to accumulate at the variable diameter of the drilling tool, and in serious ca...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the technical problem of incomplete reverse circulation formation of existing reverse circulation drill bits in broken formations, and provide a powerful suction reverse circulation core drill bit based on the Coanda Coanda effect

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