RU2509199C2 - Drill bit with washing units - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: drill bit with washing units includes a body with an attachment thread to a drilling string, rock-breaking elements, channels to supply washing liquid to a bottomface, seats at the outlet from channels for placement of wear-resistant attachments with sealing and stop elements. At the inlet of the channel for supply of washing liquid from a nipple part to the bottom face there is a protective bushing from wear-resistant material, protruding with one side above the bottom of the hole in the nipple part of the body and having a support circular ledge at the opposite ledge, the external diameter of which is more than the diameter of the inlet channel. The attachment has in the upper part a smooth external cylindrical surface contacting with an elastic sealing ring, below on its external surface there is a side thread, and at the bottom - end ledges for a box wrench. Both end surfaces of the support circular ledge contact with elastic sealing rings, the first ring is installed in the cavity between the ledge on the wall of the inlet channel and the upper end surface of the circular ledge, the second one - between the lower end surface of the circular ledge and the upper end of the attachment. Below the attachment there is a stop check-nut with slots or holes at the end for another rotary box wrench, and the check-nut is installed on the thread in the seat wall for the attachment.

EFFECT: increased reliability and durability of a drill bit with replaceable washing units.

4 cl, 8 dwg

Description

The invention relates to the field of drilling equipment, and in particular to a tool for drilling deep wells in the oil and gas industry.

Known drill bit with a flushing unit [1], adopted for an analogue containing a nozzle made of wear-resistant material, fixed in the hole of the socket on the body of the paw with the direction of the jet of flushing fluid coming from it into the free space of the face between adjacent cones. The nest under the nozzle is connected by a channel to the internal cavity of the bit, from where the flow initially enters the internal cavity of the nozzle with a profile that forms a jet, and then onto the face, sparges the sludge of the destroyed rock, detaches it from the face and carries it along the annulus to the top of the well for sludge treatment and new pumping to the bottom.

A rectangular groove is made on the wall of the nest for the nozzle to install an elastic sealing ring with an inner diameter smaller than the outer diameter of the nozzle and an outer diameter equal to or slightly larger than the outer diameter of the nest of rectangular cross section. Due to the elastic properties, the ring covers the nozzle when it is pushed through the sealing ring installed in the groove. In order to keep the nozzle from falling out at high pressure of the flushing fluid, an annular half-groove of semicircular section and a corresponding half-groove of semicircular section on the outer surface of the nozzle body are made in its wall before exiting the nest.

When installing the nozzle, two half-spaces are combined on the wall of the nest and on the surface of the nozzle, and a toroidal annular surface is formed. In the body of the tide, a round hole is drilled under the nozzle on the body of the paw, the axis of which coincides with the ring axis of the resulting toroidal annular space. Through a hole in the tide, a rod in the form of a nail made of soft material is introduced into the toroidal space, which is a stopper from the nozzle leaving the socket during drilling. The nozzle can fall out of the nest during drilling only by cutting off half of the profile along the entire length of the nail inserted into the toroidal space. If it is necessary to replace the diameter of the outlet section of the nozzle according to the drilling conditions, the nail is pulled out of the head.

After replacing the size in diameter, the new nozzle is inserted into the removed position, the nail is straightened and hammered around the nozzle again. The elastic rubber ring can be changed if necessary.

This version of a drill bit with a nozzle for a flushing nozzle is widely used by domestic and foreign bit companies for the production of roller cone bits. However, in diamond PDC and matrix steel bits, such a fastening and sealing pattern for flushing nozzles is practically not used. This is due to both structural and technological inconveniences, since numerous flushing holes with carbide nozzles are most often located on convex surfaces of the body with a recess between the blades, with different distances and inclinations relative to the axis of the bit. For hundreds of commercially available diamond bit sizes, it is necessary to develop thousands of individual programs to carry out individual flushing units. This circumstance made us look for other, more convenient options.

Another drill bit with a flushing unit [2] is also known, which is also taken as an analogue, in which a steel spring expansion ring is used as a locking device, installed in an annular groove on the wall of the socket hole under the nozzle, part of the end surface of the ring enters the groove groove, and part protrudes inside the diameter of the nest and prevents the nozzle from flying out during drilling. There are two options for installing the snap ring. The first option - the snap ring is installed in the groove of the slot below the solid nozzle. The second option - the snap ring during installation is installed in the groove on the nozzle itself, is compressed with the help of "antennae" with special pliers with protrusions under the antennae holes. The nozzle together with the compressed ring is inserted into the socket in the paw, and the retaining ring is released from compression when it coincides with the width of the groove under the ring on the wall of the socket for the nozzle. Changing the size of the nozzle hole, necessary for hydraulic calculations, is performed in the reverse order - first, the circlip is compressed, and then the nozzle is pushed out of the socket. The installation scheme of the sealing elastic ring is the same as in the previous analogue. If necessary, this ring can be changed with the nozzle.

The disadvantages of both options are as follows. It is technologically difficult to harden the retaining rings - under-tempered ones do not return to their original position after compression, overheated ones can be too fragile and break when changing the nozzle. Therefore, the replacement of nozzles in the field, especially in winter, is difficult. In addition, when drilling at high pressures on the riser, the nozzles act on standard thin retaining rings, bend them in diameter, bend in thickness and gradually push the nozzles into the face along with the retainer rings.

Another PDC drill bit with a flushing unit [3] is adopted as a prototype. It includes a housing with a connecting thread to the drill string, rock cutting elements, channels for supplying flushing fluid to the bottom of the hole, nests at the outlet of the channels to accommodate wear-resistant nozzles with sealing and locking elements, and at the entrance to the channel for supplying flushing fluid to the bottom of the nipple part protective sleeve made of wear-resistant material, protruding on one side above the bottom of the hole in the nipple part of the housing and having a supporting annular protrusion at the opposite end, diameter greater than the inlet diameter of the nozzle has in its top part smooth outer cylindrical surface in contact with an elastic sealing ring on the lower outer surface thereof has a lateral thread, and bottom - end projections for a socket wrench.

The disadvantages of the prototype are as follows. There is no inlet clearance protection between the protective sleeve and the housing. There is no protection for the gap between the ends of the protective sleeve and nozzle. The PDC bit can be used up to hundreds of hours, so the nozzles can be turned up and fall out due to vibration at the bottom. It is necessary to increase the reliability of the locking element. The side and end sealing of the protective sleeve and nozzle is not sufficiently reliable.

The aim of the invention is to provide a reliable embodiment of a drill bit with flushing units.

The technical result of the present invention is to increase the reliability and durability of the PDC drill bit with interchangeable flushing units. This result is achieved by the fact that in the drill bit with flushing units, including a body with a connecting thread to the drill string, rock cutting elements, channels for supplying flushing fluid to the bottom, jacks at the outlet of the channels for accommodating wear-resistant nozzles with sealing and locking elements, and a protective sleeve of wear-resistant material is installed on the inlet of the channel for supplying flushing fluid to the bottom of the nipple, protruding on one side above the bottom of the hole in the nipple part a mustache and having a supporting annular protrusion at the opposite end, the outer diameter of which is larger than the diameter of the inlet channel, the nozzle has a smooth outer cylindrical surface in contact with the elastic sealing ring in the upper part, side thread is lower on the outer surface, and end protrusions for the end key, while the end surfaces of the support annular protrusion are in contact with the elastic sealing rings, the first ring is installed in the cavity between the ledge on the wall of the input ala and the upper end surface of the annular projection, the second - between the lower end surface of the annular projection and the upper end of the nozzle, and the lower nozzle is mounted on a threaded socket wall under the nozzle retainer locknut with grooves or holes on the other end for pivoting the mechanical key.

In addition, in another embodiment of the proposed bit, in addition to the channel inlet, the gap between the protruding protective sleeve and the wall of the hole beneath it is additionally sealed with an annular layer of welding, surfacing or soldering.

In another embodiment of the proposed bit, the contact end surfaces: the lower at the annular protrusion of the protective sleeve, the upper end of the nozzle and the sealing ring installed between them, are located at an acute angle α = 20 ÷ 45 ° from the side of the inlet to the washing hole.

In the next embodiment of the proposed bit, a thread is made on the end of the protective sleeve protruding above the bottom of the nipple, the nut is screwed on, with its help an elastic sealing ring is pressed against the bottom surface and seals the gap between it and the protective sleeve.

In the proposed bit, the flushing unit provides a full guarantee of fixing the nozzle in the flushing unit during the entire life of the bit, the reliability and ease of changing the nozzle when such a need arises for drilling.

During installation, the nozzle is wrapped, compressing the first and second elastic rings to the stop. The clamping force can be calibrated using a torque wrench.

List of drawings

The figure 1 presents a fragment of the proposed drill bit with the first embodiment of the flushing unit.

In figure 2 and figure 3 presents two options of lock nuts for fixing the installed nozzle.

The figure 4 presents a view And the lower end of the nozzle.

In figures 5, 6, 7 and 8 presents fragments of the proposed drill bit, respectively, with the second, third and fourth variants of the flushing unit.

In the figure, 1 positions denote: 1 - the body of the drill bit, 2 - the bottom of the hole of the nipple part of the bit, 3 - the channel from the nipple part of the bit to the bottom side, 4 - the protective sleeve, 5 - the first elastic sealing ring, 6 - the annular protrusion of the protective sleeve, 7 - inner end of the protective sleeve, 8 - outer end of the protective sleeve, 9 - step on the wall of the hole to accommodate the protective sleeve, 10 - second elastic sealing ring, 11 - nozzle, 12 - annular groove on the wall of the hole for the nozzle, 13 - third sealing ring, 14 - thread on the sides o of the nozzle surface, 15 - thread on the side surface of the nozzle hole, 16 - protrusions on the bottom of the nozzle for the turn key, 17 - lock nut for fixing the installed nozzle, 18 - thread on the side surface of the lock nut, 19 - thread on the wall of the lock nut hole.

In figure 2, the position indicated: 20 - grooves for the socket wrench on the first embodiment of the lock nut 17, the remaining positions are the same as in figure 1.

In figure 3, the position denotes: 21 - holes for the socket wrench on the second version of the nut 22, the remaining positions are the same as in figure 1.

In the figure, 4 positions denote: 23 - protrusions on the lower end of the nozzle, 24 - grooves for the socket wrench on the lower end of the nozzle, 25 - the central hole in the nozzle.

Figure 5 shows the following version of the proposed bit, the position indicated: 26 - sealing ring layer of welding, surfacing or soldering the transition from the bottom surface 2 to the gap between the protective sleeve 4 and the wall of the hole under it. The remaining positions are the same as in the previous figures.

Figure 6 shows the following variant of the proposed bit, the positions indicated: 27 - O-ring with a different shape, close to a conical, cross-section and with a bevel under protection 28 on a protective sleeve located at an acute angle α = 20 ÷ 45 ° to the axis of the sleeve . The remaining positions are the same as in the previous figures. This allows you to provide a simultaneous clamping of the sealing ring to the end face of the protective sleeve, and to the wall of the socket under the nozzle.

In figure 7, a variant of variant 1 of the proposed bit without an elastic sealing ring 5 is proposed. The remaining positions are the same as in the previous figures.

In figure 8, the following variant of the proposed bit is proposed, without an annular welding layer 26. In this embodiment, a thread (preferably self-braking) 29 is made on the protruding end of the protective sleeve 4. The sealing elastic ring 31 is pressed, for example, by a nut 30 to the surface of the bottom 2, providing sealing of the transition from the bottom surface into the gap between the protective sleeve 4 and the wall of the hole under it.

The assembly of the washing unit according to the first embodiment (Fig. 1) or replacing the nozzle in the field is as follows. The elastic o-ring 5 is put fully into the protrusion 6 of the protective sleeve 4. Then, the sleeve 4 with the ring 5 is inserted into the hole in the body of the bit 1, the elastic o-rings 10 and 13 are installed, using the socket wrench, the nozzle 11 is fully tightened, clamping the rings 5 and 10. The reliability of the clip can be checked, for example, using a torque wrench with experimental selection of the minimum effort on a key scale. Then, a lock nut 17 is wrapped with a socket wrench, guaranteeing the absence of any nozzle flap. When changing the nozzle, the operations are carried out in the reverse order.

The assembly of the washing unit according to the second embodiment (Fig. 5) differs from the assembly of the first embodiment by the presence of welding, surfacing or soldering 26. It can be carried out after the assembly of the assembly is complete. In order to avoid burning rings 5, 10, 13 during welding, the body of the bit should be lowered into the tank with water during welding, the level of which on the nozzle side should overlap the sealing ring 5.

When changing the size of the nozzle, the lock nut 17, nozzle 11 is first turned out, and in case of damage, the elastic sealing rings 13 and 10. Then, a new nozzle 11 and lock nut 17 are screwed in place.

The assembly of the washing unit according to the third embodiment (Fig. 6) differs from the first embodiment by the presence of a conical elastic sealing ring 27, protected from erosion by a bevel 28 on the lower end of the protective sleeve 4, made at an angle to the axis of the sleeve α = 20 ÷ 45 °, when the nozzle is inverted also provided with a bevel on the upper surface in contact with the ring.

The assembly of the washing unit and the replacement of the nozzle according to the fourth embodiment (Fig. 8) differ from the first four options by the presence of a mechanical seal 31, thread 29 at the end of the protective sleeve 4 and clamping nut 30. After assembling the protective sleeve 4 with ring 5, installing rings 10 and 13 , turning the nozzle 11 and the lock nut 17 onto the end of the protective sleeve 4, a sealing ring 31 is put on, the cross section of which may be different (for example, flat, as shown in Fig. 8). By tightening the nut 30, the ring 31 tightly seals the gap between the protective sleeve 4 and the wall of the hole under it. If necessary, a guarantee against the flap of the nut 30 and its abrasive wear by the flow of washing liquid over it can be installed another lock nut (not shown).

When replacing the nozzle, the nut 30 is first unscrewed, and then disassembly and assembly are carried out similarly to option 1, followed by fixing the seal 31 with the nut 30.

The results of field tests of samples of the proposed drill bits confirm their significant advantage in durability and simplified replacement of nozzles in the field.

Information sources

1. US patent No. 3084751 C1, 175-340, "the drill bit" (analog).

2. Composite - catalog of the company "Varel" (USA), 1995, p. 14 (analogue).

3. Espacenet WO 2008/060561 A1, 05/22/2008, E21B 10/61 (prototype).

Claims (4)

1. A drill bit with flushing units, including a housing with a connecting thread to the drill string, rock cutting elements, channels for supplying flushing fluid to the bottom, jacks at the outlet of the channels for accommodating wear-resistant nozzles with sealing and locking elements, and at the channel inlet for supplying the face of the flushing fluid from the nipple part has a protective sleeve made of wear-resistant material that protrudes on one side above the bottom of the hole in the nipple part of the body and has on the opposite side there is a supporting annular protrusion, the outer diameter of which is larger than the diameter of the inlet channel, the nozzle has a smooth outer cylindrical surface in contact with the elastic sealing ring in the upper part, side thread is lower on its outer surface, and end protrusions for the socket wrench are characterized by that both end surfaces of the support annular protrusion are in contact with elastic sealing rings, the first ring is installed in the cavity between the step on the wall of the inlet channel and the upper end wail surface of the annular projection, the second - between the lower end surface of the annular projection and the upper end nozzle below the nozzle is mounted on a threaded socket wall under the nozzle retainer locknut with grooves or holes on the other end for pivoting the mechanical key. 2. A drill bit with flushing units according to claim 1, characterized in that at the channel inlet, the gap between the protruding protective sleeve and the wall of the hole beneath it is additionally sealed with an annular layer of welding, surfacing or soldering. 3. A drill bit with flushing units according to claim 1 or 2, characterized in that the contact end surfaces: the lower at the annular protrusion of the protective sleeve, the upper end of the nozzle and the sealing ring installed between them, are located at an acute angle α = 20 ÷ 45 ° from the entrance to the flushing hole. 4. A drill bit with flushing units according to claim 1, characterized in that a thread is made on the end of the protective sleeve that protrudes above the bottom of the nipple and the nut is screwed on, using it an elastic o-ring is pressed against the bottom surface and seals the gap between it and protective sleeve.

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