DTH Impact Cone

Abstract

The invention discloses a down-the-hole impact cone which comprises a drill rod, an impactor and a sleeve, wherein a punch hammer is positioned in the impactor. The upper portion of the impact cone extends into the impactor to be connected with the impactor through a spline and is locked through a safety pin installed in a vertical strip-shaped hole, so that the impact cone can move up and down within a certain range relative to the impactor. The upper portion of the impact cone is provided with an L-shaped air hole, the middle of the impact cone is provided with a step, and the bottom of the impact cone is provided with a conical head. An impact shoe is located below the impact cone and is in threaded connection with the sleeve, the lower end of the impact shoe is conical and extends out of the sleeve, a channel for the lower portion of the impact cone to pass is arranged in the impact shoe, and the taper angle of the conical head is equal to that of the end of the impact shoe. When the step presses the top of the impact shoe, the conical surface of the conical head is just coplanar with the conical surface of the lower end of the impact shoe. The drilling efficiency is improved, the construction cost is reduced, the drilling scrapping is effectively avoided, and smooth core taking and sampling of a pipe following well section are guaranteed.

Description

technical field [0001] The invention belongs to the field of geological drilling engineering, and in particular relates to a down-the-hole impact cone. Background technique [0002] At present, there are three main types of drilling devices commonly used in the field of geological drilling: [0003] (1) Eccentric down-the-hole hammer follow pipe system [0004] Principle: According to the principle of eccentric mechanism, relying on a guide bit to drive an eccentric reamer, under the impact of the down-the-hole hammer, the guide drives the eccentric reamer to ream, so that the hole diameter is slightly larger than the outer diameter of the casing. The pipe follows the drill bit synchronously to protect the hole wall. [0005] Advantages: The drill bit can extend out of the casing to drill, and the casing can be followed up synchronously, and can drill into relatively hard rock formations. When encountering large turning stones, it can directly drill and follow up the casin...

AI Technical Summary

Problems solved by technology

[0006] Existing problems: First, the drill bit needs to be extended out of the casing to drill. If the drill tool is to be lifted out of the hole, the drill tool must be rotated in reverse, and the outer drill bit must be retracted into the casing through the telescopic mechanism to be lifted out.

Due to the complex working environment in the borehole, the fine sand particles often get stuck in the telescopic mechanism, causing it to fail, so that the outer drill bit cannot be retracted into the casing

In this way, the only way to pull out all the sleeves is to cause the whole hole to be scrapped and the loss is huge.

The second is that the whole hole needs to be discharged during the drilling process. When the drilling is deep, it is difficult to discharge the slag, and the drilling efficiency is reduced or it cannot be drilled.

[0010] There are problems: one is the high cost of use

If calculated at a depth of 30 meters per hole, the cost will increase by more than 30 yuan per meter, and there is no market competitiveness

The second is that the connection method between the casing and the pin is unreasonable, and the strength is not enough, and it is easy to crack at the stress concentration part of the casing, resulting in accidents in the hole

The third is that the whole hole slag needs to be discharged during the drilling process. When the drilling is deep, the slag discharge is difficult or the slag is discharged from the outside of the casing, resulting in a decrease in drilling efficiency or failure to drill.

[0015] Existing problems: First, you cannot drill in when encountering larger rocks

The second is to hit the ground with a heavy hammer, and there is no guide in the hole, which may easily cause the drilling to deviate

The third is that the conical drill bit and the pipe shoe are connected by threads. Once the conical head is removed, it cannot be reconnected, and it is impossible to drill with the pipe again, which has great limitations.

Fourth, the disassembly of the tapered drill should be completed by sending a special drill pipe into the hole. When the hole is deep, the amount of deflection is large, and the special drill pipe cannot be effectively connected with the threaded thread of the tapered drill, which may cause disassembly failure and lead to complete failure. hole scrap

As long as the tapered drill bit cannot be removed smoothly, the channel between the casing and the bottom of the hole cannot be opened, causing the hole to be scrapped

Fifth, when the heavy hammer impacts on the ground, the elasticity of the drilling tool and the casing in the hole will absorb the impact energy. Affected, the speed of following the tube gradually slows down or cannot continue to follow the tube

Sixth, it is not possible to take core samples in the follow-up well section

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