RU1781407C - Step bit - Google Patents

Abstract

The invention relates to mining, and in particular to a rock cutting tool for drilling without coring, and improves bit performance by increasing the resistance of the rock cutting elements and improving the removal of sludge. In the housing 1 there are additional washing grooves 6, which are located in the washing grooves 2. The washing grooves 2 at each stage are interconnected and are located at an angle of 45 ... 75 ° to the axis of the bit. The height of each step refers to its width as 1: 3. During the operation of the bit, due to the flushing grooves communicated at each stage at each stage, repeated grinding of the sludge is excluded, which contributes to an increase in the resistance of the rock cutting elements. Slots 6 and slope of slots 2 at an angle of 45 ... 75 ° contributes to better sludge removal. The ratio of the sizes of the elements of the steps 1: 3 helps to increase the performance of the bit. 4 ill.

Description

The invention relates to mining, and in particular to a rock cutting tool for drilling without coring.

Known stepwise cutting bits consisting of a body with logs reinforced with hard alloy plates and flushing channels made in the body.

Structurally, these bits can be separated for drilling soft loose rock and for drilling medium hard and hard rock.

In drill bits intended for drilling soft loose rock, the blades are long and the steps have a height equal to or greater than the width. Moreover, on the blades x, the ratio of the height and width of the steps forms an acute "p, of the inclination of the end face of the bit. The flushing grooves formed between the body and the blades have a large area, and the side flushing channels are located very high from the bottom. This design of the bits provides high efficiency when drilling soft loose rocks, but does not provide effective drilling in hard fractured rocks. h

In bits intended for drilling in hard and medium hard formations, the length of the blades and the height of the steps are reduced and they form an obtuse angle of inclination of the working end to the bottom of the well. At the same time, the space of the flushing grooves is reduced, which makes it impossible to use them in soft loose rocks, where grooves are clogged with drilled rock, pressing, grooving and raising the tool for cleaning the bit.

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The closest in technical features is a stepped bit containing a housing with a central flushing channel, the ends of which are divided into sectors by inclined flushing grooves, and flushing channels located in the grooves and in communication with the central flushing channel.

The design of these bits provides for efficient hard rock drilling. The use of these bits in rocks alternating in drillability is inefficient, due to structural disadvantages.

The location of the inclined washing grooves separately at each stage leads to the ingress of slurry material under the subsequent stages, thereby secondary grinding of the slurry material and increased wear of carbide weapons. The absence of additional flushing grooves in the bottom parts of the inclined grooves when drilling in plastic rocks does not provide effective removal of sludge. It leads to clogging of inclined grooves and side flushing channels, especially when drilling wells with complete absorption of flushing fluid with minimal flow to the bottom.

The aim of the invention is to increase the productivity of drilling in alternating hardness rocks by increasing the resistance of rock cutting elements and improving the removal of sludge.

This is achieved by the fact that the housing is made with additional flushing grooves located in the bottom parts at the outlet of the inclined grooves and communicated with the flushing channels, and the height h refers to the width I of the housing steps as 1: 3, while the inclined flushing grooves of the steps made combined with each other and located at an angle to the axis of the bit 45-75 °.

The execution of the inclined washing grooves 2 at an angle to the axis of the bit 45-75 ° provides better removal of the sludge, and combining them with each other increases the resistance of the rock cutting elements by preventing re-grinding of the sludge.

In FIG. 1 shows a general view of the bit; in FIG. 2 - end view of the bit; in FIG. 3 - sectional bit; in FIG. 4 is a graph of the change in drilling speed versus height to width of steps.

The stepped bit consists of a body 1, divided into three sectors by inclined washing grooves 2 with three steps 1, II, III, reinforced with hard alloy plates 3. In the body of the bit there is a central channel 4 and side washing channels 5 located along the inclined washing grooves 2, perpendicular to the plane of the groove. The housing 1 is made with additional washing grooves 6 located in the bottom portions at the outlet of the inclined grooves 2 and communicated with the side washing channels 5. Opening the washing channels 5 with additional washing grooves 6 improves the removal of sludge. The height of the steps h refers to the width of the I steps as 1: 3. According to the studies, the height of the steps h during drilling in rocks of different drillability varies between 3-5 mm, and the width of the steps should be 3 times greater. The ratio of h to the length of I steps at peripheral points forms a tangent line with an angle of inclination p.

Inclined flushing grooves of 2 steps of the housing 1 are made combined with each other and are located at an angle to the axis of the bit 45-75 °.

When drilling, the flushing fluid flows through the flushing channels 5 and 4 to the bottom of the well, captures the destroyed rock, cools the hard alloy plates and, along the inclined flushing grooves 2 and additional flushing grooves b, carries the rock to the wellhead. In the cavity of the central channel 4, during drilling, fragments of core material are formed, which is discharged into the grooves through the windows 9 with the washing liquid 2. The arrangement of the hard alloy plates by sectors provides for the effective destruction of rocks with different drillability, and the developed system of washing channels and grooves ensures the effective and timely removal of the destroyed rocks from under the end face of the bit.

PRI me R. In PGO Center geologists, bits with the following geometric bits were tested

1. mm mm

2. mm

3.p & mm 14mm: 1 1: 1.75

4. mm mm, 4: 1

5. b 18mm1 14mm b: 1 1.29: 1

When testing the criterion for the performance of the bit, a change in the mechanical drilling speed was adopted depending on the geometrical dimensions for different rocks (from rocks of category II to rocks of category VII).

The test results are shown in the graph of FIG. 4. From the graphs it follows that the ratio is optimal

since the mechanical drilling speed varies within small limits (from 20 to 15 m / h) regardless of the rock category.

In other cases, this change in velocity has an unacceptable spread. The angle of inclination of the steps p with a ratio of the height and width of the step 1: 3 affects the angle of inclination of the washing grooves a, which should be three times larger. This provides reliable removal of the destroyed rock from the bottom of the well.

Using the proposed bit provides the following advantages compared with known designs:

- the possibility of effective drilling in rocks of various drillability by one run without changing the bit when changing rocks;

-increase in the mechanical speed of drilling in a complex of rocks;

-increase in drilling productivity and lower cost of work.

Claims (1)

SUMMARY OF THE INVENTION A stepped bit comprising a body with a central flushing channel, the ends of which are divided into sectors by inclined flushing grooves, and flushing channels located in manholes and in communication with a central flushing channel, characterized in that, in order to increase the productivity of the bit in the rocks alternating in hardness, rocks by increasing the resistance of the rock cutting elements and improving the removal of sludge, the housing is made with additional flushing grooves, located on the output parts of the inclined flushing grooves, which at each subsequent stage are made communicated with the previous ones and placed to the axis of the bit at an angle of 45-75 °, while the height h of the steps refers to their width I as 1: 3, and the additional washing grooves are in communication with the washing channels. FIG. 1 at /// FIG. 2 Fig.z Ume m / h 30 25 JAN fifteen 10Categories of breeds lo ЈNZ Fig. 4 ) ) fctfr / t 4/7) fcfBfrfcW)