RU2530956C1 - Drilling diamond bit - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: drilling diamond bit comprises a housing, the blades extending over it, equipped with rock cutting and protective cutters PDC, the washing carbide nozzles in slots on the housing, the central cavity in the nipple of the housing, the channel system supplying washing liquid to the washing carbide nozzles. In the central cavity of the nipple the device is mounted to protect the flushing nozzles from clogging, made in the form of a cylinder or other body of revolution, open at one end and closed at the other, with an outer annular shoulder from the open end for mounting and fixing on the step of the nipple cavity, a plurality of holes of round or other shapes is made in the wall of the device for passage of washing liquid. Area of the central hole in the nipple (S_NIP), the area of the maximum cross-section of the device (S_DEV), the total area of the holes in the wall of the device (S_SIDE) and the total area of the jets of washing nozzles (S_NOZ) are related by inequation S_NIP> S_DEV> S_SIDE > S_NOZ.

EFFECT: improving the reliability and efficiency of the diamond bit operation, protection against clogging of washing carbide nozzles.

4 cl, 4 dwg

Description

The invention relates to the field of rock cutting tools, namely to drilling diamond bits used for drilling deep wells.

Known drill bit [1], taken as an analog. To protect the cavities of the cones of the cones against ingress of large particles of sludge when drilling, cylindrical tubes inserted at one end into the nests are provided in the inner cavity of the shank of the bit body. The other end of the tube is closed. On the protruding part of the tube, fixed in the socket at an angle to the axis of the internal cavity, there are many holes for passage of the purge agent part into the support cavity. A positive quality of the analogue is that large particles, capable of clogging and clogging the purge hole as they accumulate, are cut off when the purge agent passes through the outer surface of the protruding tube and the hole dimensions are smaller than the size of the large particles. The negative qualities of the analogue are that it is impossible to use it in bits with washing the face.

Another drill bit is known [2], also taken as an analogue. An elastic cone-shaped reflector is placed in the inner cavity of its shank, covering the entire area of this cavity with lateral valve openings on the sides for further passage of the purge agent without large particles into the support cavity. At the end of the conical funnel there is a spring valve that opens during drilling by the pressure of the purge agent and closes when the compressors stop.

A positive quality of this analogue is also the ability to delay large particles of sludge and prevent them from falling into the cavity of the support. The disadvantage is the inability to use in bits with flushing face.

Another cone-type drill bit is known [3], also taken as an analogue. In the inner cavity of the shank on the ledge, there is an upper corrugated chamber in the form of a tube and a bell with a snap expansion ring and a groove and a movable lower chamber on the surface of the upper chamber tube with split elastic petals - sludge chippers, which rises and overlaps the holes of the perforated chamber in case of pressure in the riser falls or stops.

Known for another drill bit [4], adopted as a prototype. This is a diamond bit with PDC cutters mounted on the surface of the blades protruding above the body and the side surfaces of the body to protect against loss of diameter by the bit during drilling. In the niches between the blades, several replaceable carbide wash nozzles are installed. The larger their number in the bit, the better the face and surface of the body and the blade blades are washed, the less chance of pickling of the cutters, leading to a decrease in the mechanical speed of drilling and penetration to the bit.

An increase in the number of nozzles with a reduced diameter allows for a constant flow rate of flushing fluid to increase the number of overlap zones and improve the cleaning of the bottom. This is a positive property of the prototype.

But reducing the output diameters of the flushing nozzles often leads to a complete and dense clogging of one or more of them with scraps of rubber coatings of the turbodrills, the stator shell of the volumetric engine, or large particles of sludge. With such a blockage, flushing from one or more nozzles stops, which leads to a deterioration in flushing of the face, greasing and termination of part of the cutters and, as a result, the mechanical drilling speed and penetration to the bit decrease.

The technical result of the present invention is to increase the reliability and efficiency of the diamond bit.

The indicated technical result is achieved in that in a diamond drill bit containing a housing, blades protruding above it, equipped with PDC rock cutting and protective cutters, carbide flushing nozzles in the housings on the housing, a central cavity in the housing nipple, a system of channels leading the flushing fluid to the carbide flushing nozzles, in which a device for protecting carbide washing nozzles from clogging, made in the form of a cylinder or other body, is rotated in the central cavity of the nipple open from one end and closed from the other, with an outer annular shoulder on the side of the open end for installation and fastening on the step of the nipple cavity, a lot of holes of a round or other shape are made in the wall of the device for the passage of flushing fluid, while the area of the central hole in the nipple (S _NPC ), the maximum cross-sectional area of the device (S _SET ), the total area of the holes in the wall of the device (S _SIDE ) and the total area of the nozzles of the washing nozzles (S _US ) are related by the inequality (S _NPC > S _SET > S _SIDE > S _US ), the diameter of the holes in the wall of the device of round shape d or the largest width of such holes of a different shape b must be less than the minimum diameter of the nozzles in the range d (or b) = (0.4 ÷ 0.7) d _HACmin ; the device case is, for example, made of alloy cast irons or other wear-resistant material coated with metal carbides; the axis of the holes in the wall of the device is inclined at an acute angle α to the side of its closed end in order to reduce hydraulic losses and erosion of the wall of the central cavity of the nipple by jets of washing liquid.

The device can be fixed on the step of the nipple cavity by any known method, for example, as shown in the third analogue, using a lock nut (not shown in our diagram). The fastening should provide the ability to replace or reuse the device in another bit.

List and description of drawings

Figure 1 presents a General view of the diamond bit PDC with a steel body.

Figure 2 presents a longitudinal section of figure 1 with carbide rinsing nozzles and the proposed device for protecting carbide rinsing nozzles from clogging.

Figure 3 presents a variant of the proposed device. Figure 4 presents another variant of the proposed device. In figure 1, the positions denote: 1 - the body of the bit, 3 - flushing carbide nozzles, 4 - connecting thread, 5 - PDC cutters rock-cutting, 6 - PDC teeth to protect the diameter, 7 - grooves for the key wrench bit.

In figure 2, the positions indicated: 1, 3-7 - the same details as in figure 2, 2 - the internal cavity of the bit nipple, 8 - the proposed device, 9 - the outer annular shoulder, 10 - a step in the cavity of the nipple for installation devices.

In figure 3 and 4, the positions indicated: 8-9 - the same details as in figure 1; 11 - holes in the wall of the device for the outlet of the washing liquid into the internal cavity 2 and to the nozzles 3; 12 - wall thickness of the device, selected depending on the material and pressure on the riser; acute angle α denotes the direction of exit of the jets from the holes in the device wall, d is the diameter of these holes, b is the width of the holes of a different shape, except round, which is the main dimensional obstacle from the penetration of clogging particles.

The filter housing can be installed in the bit at the factory or just before the bit is lowered into the well. If necessary, during the forced lifting of the bit and inspection, the filter housing can be replaced with a new one, for example, with smaller holes. After locking the device, the version of which is mentioned above, the bit is lowered to the bottom. The size and shape of the holes in the filter allow you to reliably hold in a significant amount of the internal cavity of the device any scraps of rubber coatings of the drive or large particles of sludge, preventing them from falling into the flushing nozzles, and therefore avoid a decrease in drilling performance with a bit.

Information sources

1. US patent No. 6405811 of 06/18/2002, class. E21B 10/24 (analog).

2. Copyright certificate No. 1603877 dated 05/27/2000, class. E21B 10/24 (analog).

3. US patent No. 3401758 of 09.17.1968, class. 175-318 (analogue).

4. Composite catalog of Volgaburmash OJSC for 2012, p. 36 (prototype).

Claims (4)

1. A diamond drill bit containing a housing, blades protruding above it, equipped with PDC rock cutting and protective cutters, carbide rinsing nozzles in the housings, a central cavity in the housing nipple, a system of channels leading the rinsing fluid to the carbide rinsing nozzles, characterized in that a device for protecting the flushing nozzles from clogging is installed in the central cavity of the nipple, made in the form of a cylinder or other body of revolution, open from one end and closed from the other, from the outside a circular annular collar from the side of the open end for installation and fixing on the step of the nipple cavity, in the device wall there are many holes of a round or other shape for the passage of flushing fluid, while the area of the central hole in the nipple (S _NPC ), the maximum cross-sectional area of the device (S _TSI ), the total area of the holes in the wall of the device (S _SIDE ) and the total area of the nozzles of the washing nozzles (S _US ) are related by the inequality S _NPC > S _USE > S _SIDE > S _US . 2. Diamond drill bit according to claim 1, characterized in that the diameter of the round holes (d) or the largest width of the holes of another shape (b) must be less than the minimum diameter of the nozzles within d (or b) = (0.4 ÷ 0 , 7) d _{US min} . 3. The diamond drill bit according to claim 1, characterized in that the housing of the device is made of wear-resistant material or with a wear-resistant coating with metal carbides. 4. Drilling diamond bit according to claim 1, characterized in that the axis of the holes in the wall of the device are inclined at an acute angle α towards its closed end.

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