Method for passing through fracture zone during drilling of through-type air reverse circulation down-the-hole hammer

Abstract

The invention discloses a method for passing through a fracture zone during drilling of a through-type air reverse circulation down-the-hole hammer. The method comprises the following process steps that (1) judgment of the fracture zone is conducted, and specifically, 1, the deslagging speed and the deslagging amount are obviously increased and are equivalent to two times of the normal discharge amount; and 2, the gas supply pressure of a whole drilling tool gas supply system is obviously reduced and is less than or equal to 1/2 of the normal working pressure, and meanwhile, the footage is obviously accelerated and is equivalent to 3 times-5 times of the normal drilling, namely the fracture zone is judged; (2) the thickness of the fracture zone is judged, specifically, the drilling footage meeting the condition in the step (1) is the thickness h of the fracture zone; (3) the fracture zone is treated, specifically, and if the thickness of the fracture zone is less than 2m, a hole cleaning measure is adopted for penetration; and when the thickness of the fracture zone is greater than 2m, grouting well cementation wall protection is carried out; (4)detection and inspection are conducted after wall protection, specifically, a dry well section is subjected to test drilling after 7 days of cementing, the footage is controlled at about 5 m/min, and the properties of rising cuttings are observed when entering the original broken section; and the main performance is that C30 concrete rock debris is added into rock in the fracture zone, the air pressure is normal, the deslagging is normal, the predicted well cementation section is not abnormal during drilling, and normal drilling can be realized.

Description

technical field [0001] The invention relates to a down-the-hole hammer drilling method, in particular to a brand-new through-type air reverse circulation down-the-hole hammer drilling method for passing through the broken zone when drilling into the broken zone. Background technique [0002] At present, in the drilling construction of the through-type air reverse circulation DTH hammer, when drilling the broken zone, one relies on the advantage of the fast penetration of the through-type reverse circulation DTH hammer to quickly pass through, but it is difficult for the thicker broken zone Through, and even if the thin layer passes through, it is very easy to cause block stuck pipe; second, because the air is used as the circulating medium, there is basically no wall protection effect. Only in relatively complete formations, harder formations can show its drilling advantages, but The problem of retaining walls brought along therewith is very prominent, that is, the well-form...

AI Technical Summary

Problems solved by technology

[0002] At present, in the drilling construction of the through-type air reverse circulation DTH hammer, when drilling the broken zone, one relies on the advantage of the fast penetration of the through-type reverse circulation DTH hammer to quickly pass through, but it is difficult for the thicker broken zone Through, and even if the thin layer passes through, it is very easy to cause block stuck pipe; second, because