SU899823A1 - Drilling bit - Google Patents

Description

(54) DRILLING BIT

one

The invention relates to the mining industry, namely to devices for drilling wells with periodically replaceable (as wear) cutting parts.

Drill bits (chisels) are known for drilling holes in rocks of different strength categories, but they all require periodic drilling stops for their replacement (due to wear or breakage), which is always associated with significant working time, especially for disassembly lifting operations 1.

A drill bit is known for drilling wells with replaceable bottom-hole cutting parts, including a housing, a cutting element in the form of a roller cutter on a horizontal axis with two grooves, in which the housing legs, a ratchet mechanism, a spring-loaded piston and a rod, driven by the pressure of the injected fluid, are located 2

However, the design of the cutting element (sharoshka) in a known bit requires an increased axial load, and the turning of the cutting element and the replacement of the incisors are not always associated with their wear and can occur with any increase in fluid pressure. In addition, the bit has insufficiently reliable transmission of torque and axial load on the cutting

 element and low reliability of the ratchet mechanism, which uses pins on the outer surface of the roller cutter to rotate the cutting element.

The purpose of the invention is to increase the efficiency of drilling operations by increasing tool durability and sharply reducing tripping operations.

The chisel consists of a body with a shank and heads, a cutting device (in the form of a pair of radially arranged feathers),

15 mechanisms for its movement, rotation and fixation. The force is transmitted through the cutouts in the form of feathers on the lower part of the body; the washing liquid enters through special channels in the box 20.

FIG. 1 shows the proposed chisel; in fig. 2 shows section A-A in FIG. one; in fig. 3 is a view B in FIG. one; in fig. 4 is a view of B in FIG. one.

The housing 1 with the channels 2, for supplying the washing liquid, has the form of a short thick-walled cylinder, bounded on both sides of the lower 3 and supporting 4 parts. The latter forms a single whole with the plug and the shank (not shown). The lower part 3 of the housing 1 in the outer part has special notches in the form of a matrix for transmitting torque and axial pressure to the cutting device 5.

The cutting device 5, which in this case consists of paired reinforced, radially arranged feathers, is a massive structure consisting of two main parts: the first, which is smaller in size, forming a single unit with the horizontal axis of rotation of the device, and the second one has the same, in shape, pens, but of a larger size, fixed on the said axis of rotation with a tongue and nut.

The side surface of the cutting device 5 (on the side of smaller feathers), which has a spherical shape, is also reinforced with hard alloys and serves to calibrate the well.

In the working position, the upper pair of feathers is engaged with the lower part 3 of body 1 (pushed into special notches according to the shape of the specified feathers), while the next two pairs of them contact the front and rear planes with the end surface of the same part (Figs. 3 and 4).

In the process of drilling, the replacement of a regular pair of feathers (when they are worn or broken) occurs automatically, when the bit is raised from the bottom, by mechanisms of movement, rotation and fixation.

A moving mechanism for withdrawing the feathers of the cutting device from engagement with notches in the lower part 3 of the housing 1 includes a sleeve 6, inside which there is a brush 7 and a spring 8 of the turning mechanism, a guide bushing with a cup 9, a brush and a plug 10, a support plate 11. The amplitude of movement of the sleeve b in the housing 1 is limited on one side by the stop 12, on the other by the depth of the internal undercut of the lower part 3 of the housing 1. The sleeve 6 under the pressure of the spring 13 places the rod 7 and the cutting device mounted on it (through the sliding bearing 14)5 to the starting position for rotation.

The mechanism of rotation and fixation of feathers consists of a stem 7 and a spring 8, a ratchet wheel 15, a flat rotary spring 16, a paw of a fixing device 17 (with a flat spring 18 and an emphasis 19). One end of the rotary spring 16 is rigidly attached with bolts 20 to the edge portion of the sleeve 6, the other is engaged with the ratchet wheel 15. The replacement of the next pair of feathers (after moving) is performed by a flat rotary spring 16 with an independent extension of the shaft 7 with the cutting device 5 under the influence springs 8.

The movement mechanisms of rotation and fixation are protected from slit penetration by a movable diaphragm 21 rigidly attached to the rod 7.

The flushing fluid is supplied through two closed channels 3 cut through the walls of the housing.

Drilling is performed as follows.

When lowering the chisel on the bottom of the upper pair of feathers of the cutting device, compressing

spring 8 and 13, is included in special cuts in the lower part 3 of the housing 1, and the adjacent two pairs of them are in contact with the end surface of the lower part of the housing (Fig. 3 and 4). With this connection, a reliable torque transmission is created.

and axial pressure on the cutting device 5, this transmission is, in addition, partially duplicated by a transverse stop 12.

Drilling is performed under conditions of normal circulation of drilling fluid supplied to the bottom of the well through channels 2, which provide cooling of the feathers, complete removal of drill cuttings, as well as cleaning the cutouts of the lower part of the housing 1 and the feathers of the cutting device 5.

When the front pair of feathers is worn, they are replaced. For this operation, it is necessary to temporarily stop drilling and, without stopping the flushing, slightly raise the bit over the bottom. This action causes automatic movement of the cutting device 5 and its disengagement from the lower part 3 of the housing 1, followed by rotation of the feathers by a given angle in the sequence described above. To continue penetration, it is required only (under the same conditions of circulation

flushing fluid) lower the chisel to the bottom. At the same time, the upper pair of feathers of the cutting device 5 is engaged again with cut-outs of the lower tip 3 of the housing 1, and the swing spring 16

becomes the starting position.

Claims (2)

1. F. A. Technology and technology exploration drilling. M., “Nedra, 1973. 2. USSR author's certificate No. 350922, cl. Е 21 В 9/08, 1970 (prototype). / 1- / 1 Fig.} .2 8id B