RU2527549C1 - Device for cleaning of inner surface of tubing (versions) - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device contains three identical scrapers fixed at the common bar, each having two identical radial knifes in the form of equilateral trapezium. All radial knives are fixed rigidly by larger bases of trapezium at lateral surface of the bar under angle of 90° to its surface parallel to its longitudinal axial line and are oriented towards each other per 180°. For the first radial knives working surfaces include lateral sides and the smaller base of trapezium. For the second radial knives working surfaces include only lateral sides of the trapezium. The filler body and rod are made hollow. For the first version: the cutter in the form of an obtuse parallelogram is fixed at the smaller base of the trapezium for the second radial knives. The cutter is fixed diagonally connecting obtuse angles and curved towards the wall of the cleaned tubing and equi-spaced from it. For the second version: radial knives of the outermost scrapers lie in the same plane and opposite in space in regard to the longitudinal axis of the bar. Radial knives of the medium scraper are unfolded in regard to the outermost ones per 90°. The cutter of two identical plates shaped as bands with grinding of both edges curved inside is fixed rigidly in the scrapers.

EFFECT: decrease in resistance to cutting, increase in cutting force, improved quantity of cleaning.

2 cl, 11 dwg

Description

The invention relates to the oil industry and can be used to remove asphalt-resin-paraffin deposits from the inner surface of tubing.

Closest to the proposed is a device for cleaning the inner surface of the tubing (options) (RF Patent No. 2393333, E21B 37/02, 06/27/2010). The device comprises an attachment unit to a flexible traction body, a weighting material, the body of which is extended, and the lower end of the weighting body has a cone shape, identical scrapers mounted on a common rod at an equal distance from each other, with the lower end being rigidly fixed to the upper end of the weighting body and the upper end is connected to the connection unit to the flexible traction body, while the longitudinal axial lines of the weighting body, the rod and the connection unit coincide, in addition, each scraper with it will have at least two radial knives identical in shape, made in the form of an equal-sided trapezoid, the sides of which are made by workers and have two-sided sharpening, and a cutter. Radial knives are rigidly fixed by large trapezium bases on the lateral surface of the rod at an angle of 90 ° to its surface, parallel to its longitudinal axial line. The cutter is rigidly fixed in the smaller base of the trapezoid of the radial knives and is made in the form of a plate with bilateral sharpening in the form of an ellipse, convex in the direction of the wall of the pipe being cleaned. One of the axes of the ellipse of the plate coincides with the smaller base of the trapezoid. The scrapers are deployed on the bar relative to each other so that in space the cutters of the upper scraper overlap the cutters of the lower scraper. The weighting body in the upper part below the attachment point of the upper scraper is provided with a through hole, the center line of which is perpendicular to the vertical center line of the body.

When performing the known device with two radial knives, the following disadvantages are identified. The shape of the cutters is an ellipse. In space, the cutters overlap each other, i.e. they are elongated along the horizontal center line. In order to obtain a high-quality cut in the overlapping zones, it is necessary to extend the ellipse horizontally to a length of not less than half the circumference of the inner wall of the tubing, which increases the cantilever for the ends of the torch. Since the ends of the torch are suspended with a long cantilever, the force exerted by them on the sheared sediment layer is weakened, which increases the cutting resistance, reduces the thickness of the shear and causes uneven thickness of the shearing of sediments along the inner perimeter of the tubing, reducing the quality of cleaning. The unevenness of the thickness of the cut is compounded by the fact that in the overlap zones in the known device there are no additional means weakening the adhesion of deposits to the tubing walls, since the inclined edges of the radial knives loosen deposits only in front of the middle part of the cutters. In addition, since the load on the end of the console when cutting is almost the same as in the place of attachment of the torch, the ends of the torch work on separation, which provokes emergency situations. Moreover, since the working edge of the torch in the form of a horizontally elongated ellipse is shallow, sections of the deposits are obtained in wide layers, which complicates the conditions for their removal from the tubing and reduces the quality of cleaning.

Thus, the closest to the proposed device for cleaning the inner surface of the tubing (options), the first option with two radial knives, in the implementation does not ensure the achievement of the technical result, which consists in reducing the cutting resistance, in reducing the cutting force, in improving the quality of cleaning , improving the conditions for removal of cut deposits and reducing the likelihood of emergency situations.

The present invention solves the problem of creating a device for cleaning the inner surface of a tubing (options), the implementation of which allows to achieve a technical result, which consists in reducing the resistance to cutting, in reducing the cutting force, in improving the quality of cleaning, in improving the conditions for the removal of cut deposits and reducing the likelihood of emergency situations.

The essence of the invention lies in the fact that in the device for cleaning the inner surface of the tubing (options), including the node connecting to the flexible traction body, a weighting agent, the casing of which is extended, and the lower end of the weighting casing has the shape of a cone, identical scrapers mounted on the common rod through an equal distance from each other, and the rod with the lower end is rigidly fixed to the upper end of the weighting casing, and the upper end is connected to the node connecting to the flexible traction body y, while the longitudinal axial lines of the weighting body, the rod and the attachment unit coincide, in addition, each scraper contains two identical in shape radial knives made in the form of an equal-sided trapezoid, the sides of which are made working and have two-sided sharpening, and the cutter is rigidly fixed on the smaller base of the trapezoid of the radial knife, the radial knives are rigidly fixed with large bases of the trapezoid on the side surface of the rod at an angle of 90 ° to its surface, parallel to its longitudinal axial line, while the scrapers are deployed on the bar relative to each other.

According to the first embodiment, the new one is that the device contains three scrapers in which the first and second radial knives are rotated 180 ° relative to each other and are rigidly fixed by large trapezium bases on the side surface of the rod symmetrically with respect to its longitudinal axial line, with a smaller base in each scraper the trapezoid of the first radial knife is made working and has two-sided sharpening, and the cutter is fixed on the smaller base of the trapezoid of the second radial knife, while the scrapers are deployed, the next one the previous one in such a way that the cutters are 120 ° offset from each other and overlap each other, while the cutter is a plate in the form of an obtuse parallelogram with a sharpening of the working edge inward, which is secured in each scraper by means of a recess on the smaller base of the trapezoid the second radial knife diagonally connecting obtuse angles, curved in the direction of the wall of the pipe being cleaned and equidistant from it, while the length of the diagonal connecting acute angles of the parallelogram, t It is such that in space the scraper cutters overlap each other, in addition, the weighting body and the rod are hollow, while the rod is attached to the lower end of the weighting body with the formation of a common coaxial internal cavity and with the possibility of communicating a common internal cavity with the outer space at the junction of the rod with a node connecting to a flexible traction body.

According to the second variant, it is new that the device contains three scrapers in which the first and second radial knives are rotated 180 ° relative to each other and are rigidly fixed by large trapezium bases on the side surface of the rod symmetrically with respect to its longitudinal axial line, with a smaller base in the extreme scrapers the trapezoid of the first radial knives is made by the worker and has two-sided sharpening, in addition, the radial knives of the extreme scrapers lie in the same plane, while the radial knives of the same name of the extreme scraper are spatially opposite relative to the longitudinal axial line of the rod, and the radial knives of the middle scraper are rotated 90 ° relative to the extreme, in addition, a cutter is rigidly fixed in the scrapers, which is two identical plates in the form of tapes with sharpening of both edges inward, the ends of which are connected to form the tips and are rigidly fixed on the smaller bases of the trapezoid of the second radial knives of the extreme scrapers with the formation of an angle between them at which the working surface of the cutter plates is equidistant from the inner side the surface of the tubing, with the middle part of the plates mounted respectively on the smaller radial knife base of the middle scraper symmetrically relative to the longitudinal center line of the rod, the weighting body and the rod are hollow, while the rod is attached to the lower end of the weighting body with the formation of a common coaxial inner cavity and with the possibility of communication of the common inner cavity with the outer space at the junction of the rod with the node connecting to the flexible traction body.

The technical result when implementing the claimed device for cleaning the inner surface of the tubing (options) is achieved as follows.

For all options, the essential features of the claims are: “A device for cleaning the inner surface of a tubing, including a connection unit to a flexible traction body, a weighting agent whose body is extended, and the lower end of the weighting body has a conical shape, identical scrapers attached to a common rod through an equal distance from each other, and the rod with the lower end is rigidly fixed to the upper end of the body of the weighting material, and the upper end is connected to the node connecting to the flexible traction organ, while the longitudinal axial lines of the weighting body, the rod and the attachment unit coincide, in addition, each scraper contains two radial knives identical in shape, made in the form of an equal-sided trapezoid, the sides of which are made by workers and have two-sided sharpening, and a cutter, rigidly fixed on the smaller base of the trapezoid of the radial knife, the radial knives are rigidly fixed by large bases of the trapezoid on the side surface of the rod at an angle of 90 ° to its surface, parallel to its longitudinal axial line, When this scraper deployed on the rod relative to one another ... "are an integral part of the inventive device in combination with the remaining features provide significant performance and implementation of the claimed invention and, therefore, provide the achievement of the claimed technical result.

In each embodiment, the device contains three identical scrapers, each of which contains two identical radial knives in the form of an equal-sided trapezoid, which are rotated 180 ° relative to each other and are rigidly fixed by large bases of the trapezoid on the side surface of the rod symmetrically about its axis. As a result, the scraper's radial knives lie in the same plane. In this case, the scrapers are fixed on a common rod through an equal distance from each other and the next one is deployed relative to the previous one. Since the rod with the lower end is rigidly fixed on the upper end of the housing, and the upper end is connected to the node connecting to the flexible traction body, the proposed geometry and fixing of the radial blades of the scraper allow them to simultaneously perform the function of the ribs to stabilize the position of the housing during its movement, which prevents the rotation of the housing in the tubing under the influence of a moving fluid during operation of the device, which reduces the resistance to cutting, improves the quality of cleaning and reduces the likelihood of emergency situations.

In the scrapers, everything, the edges of the first (the smaller base of the trapezoid and the sides of the trapezoid), and the side edges of the second radial knives (sides of the trapezoid) are made by workers with double-sided sharpening. In this case, they are structurally in front of the cutters. As a result, when moving the scrapers, the radial knives loosen in front of the cutters on the tubing walls, thereby reducing the cutting resistance. As a result, the cutting resistance is reduced and the operating conditions of the torches are improved and the quality of cleaning is improved. At the same time, the cutting force is reduced, which increases the stability of the entire mechanism and reduces the likelihood of emergency situations. In addition, due to bilateral sharpening, loosened deposits are, firstly, thrown into the tubing, and secondly, when moving under the action of the oncoming gas-liquid mixture flow, they are broken into sharpened edges of the knives into smaller fractions, which contributes to their active removal of the gas-liquid mixture from the tubing and improves the quality of cleaning.

According to the first embodiment, the device contains three identical scrapers, each of which contains two identical radial knives (first and second) in the form of an equal-sided trapezoid. In each scraper, all sides of the trapezoid of the first radial knife are made by workers, and in the second radial knives only sides are made by workers. The working sides of the radial cutters have double-sided sharpening.

In this case, on a smaller base of the trapezoid of the second radial knife, the cutter is rigidly fixed. The cutter is a plate with a double-sided sharpening in the form of an obtuse-angled parallelogram, which is mounted on the smaller base of the trapezoid of the radial knife diagonally connecting obtuse angles, is bent in the direction of the wall of the pipe being cleaned and equidistant from it.

As a result, when cutting sediments, the cutting technique resembles the operation of a plow: cut sediments fall off to the width of the torch on both sides of the fixing line of the cutting insert. Since the cutter plate is equidistant from the tubing walls, the cut is uniform, which improves the quality of cleaning. At the same time, thanks to the sharpening inside the cutter plate, the cut deposits are discarded into the tubing, and due to the inclination of the sides of the cutter plate relative to the attachment point, the cut deposits fall simultaneously to the sides of the central cut, breaking into small pieces, which facilitates their removal from the tubing. Moreover, since the sides of the torch plate are inclined, this violates the stability of the trimmed deposits, which contributes to a more rapid separation of the cut deposits, and also provokes a weakening of adhesion of adjacent layers under the influence of their own weight. The latter reduces the cutting resistance for the sides of the torch with its further advancement, which increases the quality of cleaning, reduces the cutting force and helps to stabilize the operation of the device.

At the same time, fixing the cutter in the recess of the edge of the second radial knife allows the cutter to be fixed almost flush, which ensures a uniform cut. In addition, with this fastening of the cutters during the movement of the scrapers, the lateral working edge of the second radial knife, having a two-sided sharpening, which performs loosening of deposits in front of the cutter, cuts the resistance to cutting and cuts into the sediment layer first. The cutter cuts off already loosened deposits, which improves the quality of cleaning, reduces the effort when cutting deposits and increases the stability of the entire device, reduces the likelihood of emergency situations. In addition, since when moving the scrapers, the radial knives of the scrapers loosen before the deposit cutter on the tubing surface, the contact time of the cutting knives with asphalt-resin-paraffin deposits decreases, which also reduces the cutting resistance and, together, improves the quality of cleaning, the stability of the device, and reduces the likelihood of emergency situations.

In the claimed device, the scrapers are deployed subsequent relative to the previous one so that the cutters are displaced in space one relative to the other by 120 °. In addition, the torch plate is curved in the direction of the wall of the pipe being cleaned so that its working surface is equidistant from the surface of the walls being cleaned and has a diagonal length connecting the acute angles of the parallelogram of the torch plate, in which the scrapers cutter space overlap each other. Thus, each cutter captures more than 1/3 of the lateral surface of the tubing. As a result, the cut is performed on a cylindrical surface, which ensures a uniform cut of deposits from the inner surface of the tubing along the entire perimeter, which improves the quality of cleaning.

As shown above, in the prototype the ends of the torch are fixed with a long console, which makes insufficient for the ends of the torch the forces formed by the weighting agent for high-quality cutting of deposits. In the claimed device, the ends of the cutter are also fixed with a long console, however, the proposed geometry of the radial knives and cutters, the proposed fastening of the cutters, as well as their combined action of all the cutting elements of the device, provide the possibility of reducing the cutting resistance, high-quality and uniform cutting of deposits across the entire width of the cutter plate. This is explained by the following.

As already shown above, the cutter is included in deposits that are previously loosened by the lateral working edge of the second radial knife on which the cutter is fixed, i.e. the adhesion of deposits to the tubing wall in front of the working angle of the torch (obtuse angle) is already weakened, and therefore, the cutting resistance is reduced.

The cutters are mounted on the smaller bases of the trapezoid of the second scrapers and overlap each other in space. As a result, the first radial scraper blades, which are rotated 180 ° relative to the second radial knives, are in which all the edges are made with double-sided sharpening, are located inside the overlapping zone formed by the cutters. As a result, when moving the scrapers, the first radial knives, working with all the edges, loosen the deposits on the tubing surface in front of the cutters in the overlap zone, improving the cutting conditions inside the overlap zone, and therefore, reducing the cutting resistance inside the overlap zone formed by the cutters. In addition, a decrease in cutting resistance is also facilitated by the fact that when the torch enters the deposition layer with an obtuse angle and when it is further advanced simultaneously with the cutting of the layer due to the geometry of the torch, the balance is disturbed and the adhesion of deposits to the tubing walls on both sides of the torch attachment is weakened, which reduces the force required to cut layers located on both sides of the torch attachment. As a result, despite the rather long cantilever of securing the ends of the torch, the conditions for cutting deposits on its sides are improved, and therefore, the cutting resistance is reduced and it is possible to perform high-quality surface cleaning.

When cutting deposits in tubing, cutting surfaces come into contact with asphalt-resin-paraffin deposits, which contain a large amount of paraffin mixed with sand, which leads to a high coefficient of friction when they are cut and increases cutting resistance. The proposed device allows to reduce the proportion of the influence of the coefficient of friction introduced by him in the formation of resistance to cutting. The declared geometry of the radial knives of the scrapers and cutters, as well as the proposed fixing of the latter allows cutting deposits with minimal contact of the cutting surfaces of the device with the cut deposits: the contacting surface of the torch is uniformly reduced in both directions from its attachment point; loosening of deposits is carried out by the working edges of the radial knives. The ability to minimize the contacting cutting surfaces of the device with cut deposits is reduced by the duration of their contact with deposits on the walls of the tubing, which reduces resistance to cutting. As a result, the cutting force decreases, the quality of cleaning increases, the stability of the device increases, and the likelihood of emergency situations decreases.

According to the second variant, the device contains three identical scrapers, each of which contains two identical radial knives (the first and second) in the form of an isosceles trapezoid. The first and second radial knives are rotated 180 ° relative to each other and are rigidly fixed by large trapezium bases on the side surface of the rod symmetrically about its axis, i.e. lie in the same plane symmetrically to the axis of the rod. In addition, the radial knives of the extreme scrapers also lie in the same plane, while the radial knives of the same name of the extreme scrapers are spatially opposite relative to the axis of the rod, and the radial knives of the middle scraper are rotated 90 ° relative to the extreme ones.

The proposed geometry of the radial knives of the scrapers and the placement of the scrapers on the rod provides the possibility of fixing on them a cutter from two identical plates in the form of a tape. The ends of the plates are connected with the formation of a point and are fixed on the smaller bases of the trapezoid of the second radial knives at an angle at which the working surface of the cutting plates is equidistant from the inner side surface of the tubing, which ensures a uniform cut of deposits. In this case, the possibility of securing the cutter plates equidistant from the inner surface of the tubing is ensured, moreover, by the identity of the cutter plates, which makes it possible to symmetrically mount the cutter plates relative to the longitudinal axis of the rod, and also by the fact that the geometry of the radial knives of the scrapers allows radial knives to be made with a maximum transverse dimension, close to the inner diameter of the tubing, and the middle part of the plates is fixed respectively on the smaller bases of the radial knives of the middle scraper symmetrically relative to the rod axis.

As a result, the cutter is inclined, has a continuous working surface and is common to three scrapers, and the cutter plates are connected in a shape close to an ellipse, in which the major axis is determined by the distance between the fastening of the ends of the plates on the extreme scrapers, and the small axis is determined by the distance between the points fastenings to the central radial knives. Since the geometry of the radial knives of the scrapers allows them to be made with a maximum transverse dimension close to the inner diameter of the tubing, at the optimal distance between the scrapers, the cut of the deposits is performed according to the spatial shape, which is a truncated cylinder, the axis of rotation of which coincides with the longitudinal axis of the rod, and the side surface is the inner surface of tubing covered with sediments. In this case, the plane of the ellipse formed by the cutter plates is the inclined base of the spatial figure. As a result, the cutter is an inclined circular knife, in which, thanks to the proposed rigid fastening of the cutting inserts, the position of the working surface of the inserts relative to the inner surface of the tubing walls is fixed and the cutting angle is fixed (the angle of inclination of the ellipse plane with respect to the longitudinal axis of the rod). Due to the fact that the sides of the torch plate have a slope, this violates the stability of the cut deposits, which contributes to a more rapid separation of the cut deposits, and also provokes a weakening of adhesion of adjacent layers under the influence of their own weight. The latter reduces the cutting resistance for the sides of the torch with its further advancement, which increases the quality of cleaning, reduces the cutting force and helps to stabilize the operation of the device. As a result, the execution of the cutter inclined allows you to reduce the force required for high-quality cutting of deposits, which increases the stability of the device and reduces the likelihood of emergency situations.

In addition, in the claimed device due to the proposed rigid fastening of the torch and its implementation, two versions of the technique for cutting deposits from the walls of the tubing are used. This is explained by the following.

In the claimed device, the cutter plates are connected with the formation of a tip and are rigidly fixed on the smaller bases of the trapezoid of the second radial knives of the extreme scrapers with an angle between them, the middle part of the plates is fixed respectively on the smaller bases of the radial knives of the middle scraper symmetrically with respect to the longitudinal axial line of the rod. Thus, the cutter is divided into two parts from the point of attachment of the tip on the lower and upper second radial knives to the fastening of the middle part of the cutter plates on the middle scrapers.

During the descent of the device, the first part of the cutter (lower) comes into operation first, which, cutting into the deposits with a tip, works according to the principle of a plow, in which the sides are the first and second plates, until they are fixed on the middle scrapers. The lower part of the cutter cuts off deposits from the tubing surface facing it. When the first part of the torch is used for descent, the cut deposits fall off on both sides of the fixing line of the cutting insert. At the same time, when advancing the tip of the torch, due to the geometry of the torch, the adhesion of deposits to the tubing walls on both sides of the torch mount is weakened. As a result, the conditions for cutting sediments by its sides are improved, and therefore, the resistance to cutting is reduced.

The second part of the cutter (upper) - from fixing the middle part of the cutter plates on the second radial knives to fixing the tip on the second radial knife of the first (upper) scraper. During the descent in the second part of the torch, the working surfaces of the plates move along the surface of the tubing walls facing them, stripping off a section of deposits by a longitudinal strip with a width equal to the distance between the plates.

When lifting the device, the first and second parts of the torch are changed by the sediment shearing technique, namely: the first part of the torch strips the deposits with a longitudinal strip with a width equal to the distance between the plates from the tubing walls facing its plates, and the second part of the torch works according to the plow principle, performing a section of deposits from the tubing walls facing its plates. As a result, when lifting the device, the surface of the tubing is cleaned, moreover, by changing the technique of cutting deposits on surfaces treated during descent, which improves the quality of cleaning.

Moreover, in both cases, due to the sharpening of the cutting edges inward, the cut deposits fall off into the tubing and are carried away by a counter-gas-liquid flow.

In addition, as shown above, the slope of the cutter plates due to stability violations contributes to a more rapid separation of the cut deposits, and also provokes a weakening of adhesion of adjacent layers under the influence of their own weight. This reduces the contact time of the cutting knives with asphalt-resin-paraffin deposits, which reduces the cutting resistance and together increases the quality of cleaning, the stability of the device, reduces the likelihood of emergency situations.

Since the lateral surface of the cutter plates is equidistant from the tubing walls, the cut is uniform, which improves the quality of cleaning.

In addition, due to the declared execution and mounting of the cutter on the radial knives when moving the scrapers both during descent and when lifting in front of the cutter, the edges of the radial knives always work, namely the lateral edges of the radial knives on which the plates are fixed, and all the working edges of the first radial knives . As a result, the cutter cuts off already loosened deposits, which reduces cutting resistance. In addition, since when moving the scrapers, the radial knives of the scrapers loosen before the deposit cutter on the tubing surface, the contact time of the cutting knives with asphalt-resin-paraffin deposits is reduced, which reduces the cutting resistance and, together, improves the quality of cleaning, the stability of the device, and reduces the likelihood of emergency situations.

When cutting deposits in tubing, cutting surfaces come into contact with asphalt-resin-paraffin deposits, which contain a large amount of paraffin mixed with sand, which leads to a high coefficient of friction when they are cut and increases cutting resistance. The proposed device allows to reduce the proportion of the influence of the coefficient of friction introduced by him in the formation of resistance to cutting. This is achieved due to the fact that the proposed geometry of the radial knives of the scrapers and the cutter, as well as the proposed fixation of the latter allow cutting deposits with minimal contact of the cutting surfaces of the device with the cut deposits: the plane of the cutter is tilted, which reduces the cutting force; the contact surface of the torch is made in the form of a tape; preliminary loosening of deposits is carried out by the working edges of the radial knives. The ability to minimize the contacting cutting surfaces of the device with cut deposits is reduced by the duration of their contact with deposits on the walls of the tubing, which reduces resistance to cutting. As a result, the cutting force decreases, the quality of cleaning increases, the stability of the device increases, and the likelihood of emergency situations decreases.

For all options. It is known that when the scrapers move down, the device body takes on the flow of a gas-liquid mixture rising upward, which impedes its movement. This can lead to the device freezing on solid deposits and, with a further increase in pressure under the housing, lead to the scraper toppling with the subsequent formation of a plug. In the claimed device, the body of the weighting device and the rod are hollow, while the rod is attached to the lower end of the housing with the formation of a common coaxial inner cavity and with the possibility of communication of the common inner cavity with the outer space at the point of connection of the rod to the flexible traction body. As a result, an additional channel is formed for the upward flow of the gas-liquid mixture, which leads to a decrease in pressure on the housing from the side of the oncoming gas-liquid mixture and, as a result, improves the conditions for the operation of the scrapers: simultaneously with a decrease in the resistance of the oncoming gas-liquid flow, the cutting resistance is reduced and, therefore, the force is reduced cutting. As a result, the quality of cleaning and the stability of the device are increased, the likelihood of emergency situations is reduced.

In addition, due to the small diameter of the axial hole compared to the inner diameter of the tubing, the gas-liquid flow rate through the internal cavity common for the body and the rod significantly exceeds the sediment removal rate by the flow moving along the tubing walls. As a result, the jet of gas-liquid mixture emerging from the cavity of the rod forms vortices that pick up pieces of cut sediments, break them into smaller fractions and increase the rate of their removal from the tubing. This improves the quality of cleaning.

The proposed device in both versions allows you to get fine fractions cut off from the walls of the tubing deposits, which improves the conditions for their removal from the tubing. This is ensured by the fact that as a result of moving the device both up and down, the first radial knives loosen deposits, and the cutter cuts loose deposits around the perimeter from the walls of the tubing uniformly and simultaneously. Cut sediments crumble into the gas-liquid mixture flowing under pressure inside the tubing. Moreover, thanks to sharpening inward, cuttings cut off by cutters fall into the space between the radial knives and are picked up by the fluid flow, additionally breaking up on the working edges of the radial knives. An additional grinding of cut sediments and an increase in the rate of their removal from the tubing is facilitated by a jet of gas-liquid mixture emerging from the cavity of the rod. As a result, the conditions for removal of cut deposits from the tubing are improved and the quality of cleaning is improved.

In addition, the geometry of the radial blades of the scrapers allows them to be made with a maximum transverse dimension close to the inner diameter of the tubing. This during the operation of the device allows the scrapers to simultaneously perform the function of centralizers, which ensures uniform cutting of deposits from the inner surface of the tubing along the perimeter and improves the quality of cleaning.

For all options. Thus, from the foregoing, it follows that the proposed device for cleaning the inner surface of the tubing (options) in the implementation ensures the achievement of a technical result, which consists in reducing the resistance to cutting, in reducing the cutting force, in improving the quality of cleaning, improving the conditions for the removal of cut deposits and reducing the likelihood of emergency situations.

For all options. As a result of a patent search, a device was discovered for cleaning the inner surface of a tubing (RF Patent No. 123451, E21B 37/02, December 27, 2012), which comprises sliding scrapers connected together by a common longitudinal axial axis, upper and lower, and a weighting agent, whose body is made with a through hole along the longitudinal axis. The identified device during implementation ensures the achievement of a technical result, which consists in improving the quality of cleaning and improving the reliability of the device.

In contrast to the claimed, the known device ensures the achievement of a technical result, which consists, in addition, in reducing the resistance to cutting, in reducing the cutting force.

This is achieved by the fact that in the claimed device the body of the weighting device and the rod are hollow, while the rod is attached to the lower end of the housing with the formation of a common coaxial internal cavity and with the possibility of communication of the common internal cavity with the outer space at the point of connection of the rod to the flexible traction body. As a result, an additional channel is formed for the upward flow of the gas-liquid mixture, which leads to a decrease in pressure on the housing from the oncoming gas-liquid mixture side and, as a result, improves the conditions for the operation of the scrapers, since simultaneously with a decrease in the resistance of the oncoming gas-liquid flow, the cutting resistance decreases and, therefore, cutting force is reduced.

In the known device, in contrast to the claimed through hole is made only in the body of the weighting agent. This solves the problem of improving the quality of cleaning by improving the conditions for the removal of cut deposits by using the gas-liquid mixture exiting from the opening.

Thus, as a result of a comparative analysis of the known and claimed device for cleaning the inner surface of the tubing, no influence on the claimed technical result of the features of the formula of the known device that match the features of the distinctive part of the claimed claims.

Figure 1 shows a photograph of a device for cleaning the inner surface of a tubing, the first option; figure 2 is a schematic illustration of a device for cleaning the inner surface of the tubing, the first option, figure 3 is a view of the cutter from the side of the rod; figure 4. - view of the cutter from above; figure 5 - sharpening the working edge of the torch; figure 6 - recess on the second radial knife of the scrapers for mounting the torch; Fig.7 - sharpening the working edges of the radial knives; on Fig shows a photograph of a device for cleaning the inner surface of the tubing, a second variant; figure 9 is a schematic illustration of a device for cleaning the inner surface of a tubing, a second variant; figure 10 is a view of A; figure 11 is a top view of A.

According to the first embodiment (figure 1, figure 2), the device for cleaning the inner surface of the tubing contains three identical scrapers 1, 2, 3, mounted on a common rod 4 through an equal distance from each other. Each scraper 1 (2, 3) contains the first and second, respectively 5, 6; 7, 8; 9, 10 identical in shape radial knives made in the form of an isosceles trapezoid. All radial knives are rigidly fixed by large trapezoid bases on the lateral surface of the rod 4 at an angle of 90 ° to its surface, parallel to its longitudinal axial line. In addition, in scrapers 1 (2, 3), the first 5 (7, 9) and second 6 (7, 9) radial knives are rotated 180 ° relative to each other and are rigidly fixed by large trapezoid bases on the side surface of the rod 4 symmetrically with respect to its longitudinal axis. At the same time, the first 5 (7, 9) radial knives made the sides of the trapezoid and the smaller base, and the second 6 (7, 9) radial knives made the sides of the trapezoid. The working edges of the radial knives have two-sided sharpening. On the smaller base of the trapezoid of the second 6 (7, 9) radial knives, the cutter 11 is fixed. The scrapers 1, 2, 3 are deployed next relative to the previous one so that the cutters 11 are offset in space by 120 ° relative to each other. Cutter 11 is a plate in the form of an obtuse parallelogram with sharpening the working edge inward. The cutter plate in each scraper 1 (2, 3) is fixed by means of a recess 12, made on the smaller base of the trapezoid of the second 6 (8, 10) radial knife, bent diagonally connecting obtuse angles, curved in the direction of the wall of the pipe being cleaned and equidistant from it. The length of the diagonal connecting the acute angles of the parallelogram of the cutter 11 is such that in the space of the cutter 11 of the scrapers 1, 2, 3 overlap each other.

In addition, the device comprises a node 13 for connecting to a flexible traction body and a weighting compound 14, the body of which is extended and the lower end of the weighting body 14 has the shape of a cone 15. The rod 4 is rigidly fixed to the upper end of the weighting body 14 by the lower end and connected to the upper end to node 13 joining (swivel) to a flexible traction body (not shown). In this case, the longitudinal axial lines of the body of the weighting member 14 of the rod 4 and the connection unit 13 coincide. The body of the weighting member 14 and the rod 4 are made hollow. The rod 4 is attached to the lower end of the body of the weighting compound 14 with the formation of a common coaxial inner cavity 16 and with the possibility of communication of the common inner cavity 16 with the outer space at the junction of the rod 4 with the node 13 connecting to the flexible traction body.

According to the second embodiment, the device for cleaning the inner surface of the tubing contains three identical scrapers 17, 18, 19, mounted on a common rod 20 at an equal distance from each other. Each scraper 17 (18, 19) contains the first and second, respectively 21, 22; 23, 24; 25, 26, identical in shape radial knives, made in the form of an isosceles trapezoid. All radial knives are rigidly fixed by large trapezium bases on the lateral surface of the rod 19 at an angle of 90 ° to its surface, parallel to its longitudinal axial line. In addition, in all the scrapers, the first 21 (23, 25) and second 22 (24, 26) radial knives are rotated 180 ° relative to each other and are rigidly fixed by large trapezium bases on the lateral surface of the rod 19 symmetrically with respect to its longitudinal axis. In the extreme scrapers 17, 19 of the first 21, 25 radial knives, the sides and the smaller base of the trapezoid are made by workers, and in the second 22, 24, 26 radial knives of the scrapers 19, 20, 21 and in the first radial knife 23 of the middle scraper 18 are made working sides . All working edges of the scrapers have double-sided sharpening.

In addition, the radial knives 21, 22 of the scraper 17 and the radial knives 25, 26 of the scraper 19 lie in the same plane, while their radial knives of the same name are spatially opposite relative to the longitudinal axis of the rod 20, namely, knife 21 is opposite to knife 25, and knife 22 is opposite to knife 26. Radial knives 23, 24 of the middle scraper 20 are deployed relative to the extreme 90 °. In the scrapers 17, 18, 19, the cutter 27 is rigidly fixed, which is two identical plates 28 and 29 in the form of tapes with the sharpening of both edges inward. The ends of the plates 28, 29 are fixed on the smaller bases of the trapezoid of the second radial knives 22, 26 of the extreme scrapers 17, 19 with the formation of an angle between them at which the working surface of the plates of the cutter 27 is equidistant from the inner side surface of the tubing. In addition, at the junction of the plate 28, 29 form a tip 30. The middle part of the plates 28, 29 are mounted respectively on the smaller radial knives of the middle scraper 18 symmetrically with respect to the longitudinal axial line of the rod 20.

In addition, the device comprises a node 31 for connecting to a flexible traction body and a weighting agent 32, the body of which is extended and the lower end of the weighting device 32 has the shape of a cone 33. The rod 20 is rigidly fixed to the upper end of the weighting body 32 by its lower end and connected to the upper end to node 31 joining (swivel) to a flexible traction body (not shown). In this case, the longitudinal axial lines of the body of the weighting member 31, the rod 20 and the connection unit 31 coincide. The body of the weighting agent 32 and the rod 20 are made hollow. The rod 19 is attached to the lower end of the body of the weighting compound 32 with the formation of a common coaxial inner cavity 34 and with the possibility of communication of the common inner cavity 34 with the outer space at the junction of the rod 20 with the node 31 to attach to the flexible traction body.

For all options. As tests have shown, the ratio between the maximum diameter of the cargo shell (D1) and the diameter (D2) of the through axial hole is optimal: D2 / D1 = 1/2. In this case, when the weight of the cargo is reduced by 20% due to the through axial hole, the resistance force of the oncoming flow is reduced by 60%.

All radial knives and cutters are rigidly fixed by welding. Typically, the thickness of the radial knives and cutters is 3 mm.

Two-sided sharpening of the working edges of all radial knives can be performed with the ratio of the lengths of the sharpened sides of the outer to the inner relative to the axial edge, for example, 1: 5, for example 0.5 mm: 2.5 mm, respectively. Sharpening the working edge of the torches is usually performed from 30 to 35 ° relative to the outer edge of the edge.

The rod 4 (20) is rigidly fixed, for example, by a threaded connection with anti-rotation control, the lower end is on the upper end of the weighting body 14 (32), and the upper end is connected to the assembly 13 (31) of attachment to a flexible traction body, for example to a swivel, which reduces the chance of twisting the wire (not shown).

The length of the smaller base of the trapezoid of the radial blades of the scrapers on which the cutters are fixed, and therefore, the height of the cutters, is selected from the condition that the maximum allowable size of the joint gap in the tubing string is exceeded, which ensures unhindered passage of the joints with scrapers when moving the device in both directions.

The weight of the weighting compound 14 (32) is selected based on the characteristics of the well or based on a high-yield well having a high pressure (and, therefore, high speed) of the fluid moving in it. The latter makes the weighting agent universal.

The length of the body of the weighting agent is selected based on the fact that the device, together with the scrapers and the connection unit to the flexible traction unit, is included in the lubricator.

Before assembling the device, the actual data on paraffin deposits in the tubing of the well to be processed are taken into account, and taking into account the characteristics of the well and the formation, the weight of the weighting body and scrapers of the appropriate design and diameter are selected.

The cone 15 (33) can be made as a separate part and is rigidly fixed to the lower end of the body of the weighting compound 14 (32), for example, by a threaded connection with control against unwinding.

The weighting body 14 (32) in the upper part may be provided with a through hole (not shown), the axial line of which is perpendicular to the vertical axial line of the weighting body, made in the upper part of the weighting body 14 (32) below the point of attachment of the upper scraper 11 (17), which allows you to quickly replace the scraper wire after the development of its resource. For this, the rod with scrapers is lifted into the lubricator, a pin is inserted into the hole, the position of the entire scraper is fixed, the spent wire is untied and a new one is tied.

The device is made of steel, which must be corrosion-resistant, as well as resistant to acids and alkalis. All threaded connections are locked with a Grover washer or split.

All variants of the claimed device have the ability to perform rigid joints of the rod with scrapers with a weighting body, cone and connection unit dismountable, for example, threaded. As a result, it is possible to quickly change the scrapers to other design dimensions both as the tubing is cleaned and when switching to another well. Threaded connections lock Grover washer.

The assembly includes connecting to the lower end of the cone body, and to the upper end - the lower end of the rod with scrapers, and to the upper part of the rod - the device connecting to the traction body.

According to the first option

The maximum transverse size of the scrapers is close to the inner diameter of the tubing (usually less than 1 mm). The choice of the transverse size of the scraper is determined based on the characteristics of the well, while the transverse size of the scraper is inversely dependent on the density of paraffin deposits and in direct relation to the flow rate of the well.

The length of the smaller base of the trapezoid of the second radial knives 6, 8, 10 to the recess 12, in which the cutter 11 is mounted, is selected from the condition that the maximum allowable size of the connecting gap in the tubing string is exceeded, and the height of the cutter 11 (the length of the diagonal connecting obtuse angles) is chosen less than this size, which ensures unhindered passage of joints with scrapers when moving the device inside the tubing in both directions.

According to the second option, the length of the smaller base of the trapezoid of all the radial knives is selected from the condition that the maximum allowable size of the docking gap in the tubing string is exceeded, and the height of the cutter 27 mounted on them is chosen to be smaller than this size, which ensures unhindered passage of the joints with scrapers when moving the device inside the tubing in both directions.

The claimed device for cleaning the inner surface of the tubing (options) works as follows.

The device in assembled form is introduced into the lubricator. Then the valve of the lubricator is opened and the device is inserted into the tubing to be cleaned.

For all options. The cone 15 (33) first crashes into the deposits, which centers the position of the device in the tubing. The cone 15 (33) provides laying of the working channel: it loosens and at the same time smooths deposits in front of the lower scraper 3 (19). In this case, the conical shape reduces the oncoming resistance of the medium as the weighting material 14 (32) moves down, which facilitates the advancement of the entire device as a whole and makes it smoother.

The weighting compound 14 (32), practically without rotating, lowers under the weight of its weight, dragging the rod 4 (20) with the scrapers 1, 2, 3 fixed on it (17, 18, 19).

After passing the cone 15 (33) into the tubing to a depth exceeding the length of the body of the weighting compound 14 (32), with further descent of the device, scrapers 1, 2, 3 begin to work under the weight of the weighting compound (17, 18, 19).

According to the first option. The first radial knives 9, 10 of the lower scraper 3 cut into the deposits with the lower lateral working edges and loosen them. Then, as the scraper 3 moves downward, cutter 11 cuts into the paraffin deposits on an obtuse angle, and the smaller base of the trapezoid of the first 9 radial knife cuts from the opposite cutter. Cutter 11 begins to cut deposits on the principle of a plow. Cut strips, turning away to the sides, slide along the sides of the torch, while falling into the tubing, crumble and are carried away upstream by the fluid moving in the tubing. At the same time, when the obtuse angle of the torch 11 is moved on both sides of it along the height-reducing plate of the torch 11, the adhesion of the layers to the tubing walls is weakened, reducing the cutting resistance of the tapered ends of the torch 11. In addition, the first radial knife 9 of the lower scraper loosens in the working area of the ends of the deposition torch 11. 3, which also reduces cutting resistance.

Further, with the continuation of the descent of the rod 4 with scrapers 1, 2, 3 in the tubing, the process of cutting sediments is repeated. In this case, the second 2 and first 1 scraps come into operation sequentially, namely: the lower side edges of the second radial knife 8 (6), the cutter 11 mounted on it and the first radial knife 7 (5).

Moreover, since the scrapers 1, 2, 3 are deployed subsequent relative to the previous one in such a way that the cutters 11 are 120 ° offset from each other and overlap each other, the first radial knives 5, 7, 9 of the scrapers 1, 2, 3 are loosened deposits in the overlapping zone formed by the working ends of the cutters 11, reducing the resistance to cutting.

The oncoming stream carries the cut deposits up. Due to the distance between the scrapers 1, 2, 3, the cut off deposits do not accumulate, but are moved upward by the liquid. At the same time, they additionally crumble, breaking into radial knives 5-8 and cutters 11, which improves the conditions for their removal from the tubing.

During the return stroke, the sediment shearing process is repeated. Moreover, since the scrapers 1, 2, 3 have a transverse dimension close to the diameter of the tubing, and the scrapers in space overlap each other, then during the return stroke the device finishes the walls of the tubing.

In addition, since the transverse dimension of the scrapers 1, 2, 3 along the horizontal axial is close to the inner diameter of the tubing, while the device is moving inside the tubing, the device is centered.

According to the second option. The first radial knives 25, 26 of the lower scraper 19 cut into the deposits with the lower lateral working edges and loosen them. As the device moves down, the lower part of the cutter 27 and the smaller base of the trapezoid of the first radial knife 25 of the lower scraper come into operation. At the same time, the cutter 27 cuts into the paraffin deposits almost simultaneously on the one side — the lower tip 30 and the smaller cutter on the opposite side 27. the base of the trapezoid of the first radial knife 25. The cutter 27 cuts into the deposits with the lower tip 30, and then the side plates according to the plow principle. Thanks to the sharpening of the plates 28, 29 of the cutter 27 inward, the cut strips, turning away to the sides, slide along the sides of the plates 28, 29 of the cutter 27, while falling into the tubing, they crumble and are carried away upward by the fluid moving in the tubing. At the same time, due to the advancement of the cutter by the lower tip 30 on both sides of it along the plates 28 and 29 of the cutter 27, the adhesion of the layers to the tubing walls is weakened, reducing the cutting resistance to the plates 28, 29 of the cutter 27.

Further, when the descent of the rod 20 with the scrapers continues, the second scraper 18 comes into operation: the lower lateral working edges of the first 25 and second 26 radial knives cut into the deposits and loosen the deposits immediately before the plates 28, 29 of the cutter 27 fixed on them, reducing the cutting resistance and reducing the force on the cutter 27 in the place of its fastening, thereby increasing the structural strength of the device and reducing the likelihood of emergency situations.

Thus, when lowering, the lower part of the cutter 27, which includes half of the first 28 and second 29 plates, fixed with the formation of the lower tip 30 on the second radial knife 26 of the third scraper 19 and on the corresponding first 25 and second 26 radial knives of the second scraper 18, cuts off plow deposits.

With further descent of the plate 28, 29 of the cutter 27 in the place of their fastening on the second scraper 18 and above cut deposits in vertical stripes.

The first scraper 17 comes into operation, in which, on the smaller base of the trapezoid of the second radial knife 22, the plates 28, 29 of the cutter 27 are connected and rigidly fixed to form an angle between them. As a result, plates 28, 29 cut into the deposits by working edges connected by an angle. In addition, the lower lateral working edges of the second 22 and first 21 radial knives cut into the deposits and loosen the deposits on the tubing walls immediately before the cutter plates fixed on them and on the opposite side, respectively. With further downward movement, the parts of the plates 28, 29, mounted on the second radial knife 22 of the first scraper 17 and the second scraper, cut off the deposits in longitudinal strips.

Thus, during descent, the second part of the cutter (upper), which includes half of the first 28 and second plates 29, mounted on the corresponding first 23 and second 24 radial knives of the second scraper 18 and connected and fixed on the second radial knife 22 of the first scraper 17, cuts off deposits in vertical stripes.

The oncoming stream carries the cut deposits up. Due to the distance between the scrapers, the cut off deposits do not accumulate, but move upward with the liquid. At the same time, they additionally crumble, breaking into radial knives and cutters, which improves the conditions for their removal from the tubing through the elements of the scrapers.

During the return stroke, the second part of the cutter 27 (upper) cuts off deposits according to the plow principle, and the first part of the cutter 27 (upper) cuts off deposits in longitudinal strips. Otherwise, the process of cutting sediments is similar. Moreover, since: the cutter 27 is made continuous; the working surface of the plates 28, 29 of the torch is equidistant from the inner side surface of the tubing; the ends of the plates 28, 29 are rigidly fixed on the smaller bases of the trapezoid of the second radial knives (tip 30), and the middle part of the plates 28, 29 are rigidly fixed respectively on the smaller bases of the radial knives 23, 24 of the middle scraper 18 symmetrically with respect to the longitudinal axial line of the rod 20, then lifting device, the scrapers and cutter perform finishing. Moreover, the processing of the entire inner surface of the tubing is sequentially performed by two types of shearing technique: longitudinal strips and dump by analogy with the work of the plow.

In addition, the proposed design of all radial knives, the cutter and the mounting of the latter provide both the centralizer function both during the descent and during the lifting of the device.

For all options. In the claimed device, the weighting body 14 (32) and the rod 4 (20) are hollow, while the rod 4 (20) is attached to the lower end of the weighting 14 (32) with the formation of a common coaxial internal cavity 16 (34) and with the possibility of a common internal cavities with external space at the point of attachment of the rod 4 (20) to the flexible traction body 13 (31). As a result, an additional channel is formed for the upward flow of the gas-liquid mixture, which leads to a decrease in pressure on the body of the weighting compound 14 (32) from the oncoming flow of the gas-liquid mixture and, as a result, improves the working conditions of the scrapers. Simultaneously with a decrease in the resistance of the oncoming gas-liquid flow, the cutting resistance decreases and, therefore, the cutting force decreases. As a result, the quality of cleaning and the stability of the device are increased, the likelihood of emergency situations is reduced.

In addition, due to the small diameter of the axial hole in comparison with the inner diameter of the tubing, the gas-liquid flow rate through the internal cavity 16 (34) common for the weighting body 14 (32) and rod 4 (20) significantly exceeds the sediment removal rate by the flow moving along the tubing walls. As a result, the jet of gas-liquid mixture emerging from the cavity of the rod forms vortices that pick up pieces of cut sediments, break them into smaller fractions and increase the rate of their removal from the tubing. This improves the quality of cleaning.

Claims (2)

1. A device for cleaning the inner surface of the tubing, including the connection unit to the flexible traction body, a weighting agent, the body of which is extended, and the lower end of the weighting body has the shape of a cone, identical scrapers mounted on a common rod through an equal distance from each other, moreover, the rod with the lower end is rigidly fixed to the upper end of the body of the weighting material, and the upper end is connected to the node connecting to the flexible traction body, while the longitudinal axial lines of the weighting body I, the rods and the attachment unit are the same, in addition, each scraper contains two identical in shape radial knives made in the form of an isosceles trapezoid, the sides of which are made by workers and have two-sided sharpening, and a cutter rigidly fixed to the smaller base of the trapezoid of the radial knife, radial knives are rigidly fixed with large trapezoid bases on the lateral surface of the rod at an angle of 90 ° to its surface, parallel to its longitudinal axial line, while the scrapers are deployed on the rod relative to each other, characterized in that the device contains three scrapers in which the first and second radial knives are rotated 180 ° relative to each other and are rigidly fixed by large bases of trapeziums on the side surface of the rod symmetrically with respect to its longitudinal axial line, and in each scraper there is a smaller base of the trapezoid of the first radial knife made by the worker and has a double-sided sharpening, and the cutter is mounted on the smaller base of the trapezoid of the second radial knife, while the scrapers are deployed subsequent to the previous one in such a way that the cutters are 120 ° offset from each other and overlap each other, while the cutter is a plate in the form of an obtuse parallelogram with a sharpening of the working edge inward, which is secured in each scraper by a recess on the smaller base of the second radial the knife along the diagonal connecting the obtuse angles is bent in the direction of the wall of the pipe being cleaned and equidistant from it, while the length of the diagonal connecting the acute angles of the parallelogram is such that In this way, the scraper cutters overlap each other, in addition, the weighting body and the rod are hollow, while the rod is attached to the lower end of the weighting body with the formation of a common coaxial internal cavity and with the possibility of a common internal cavity communicating with the outer space at the junction of the rod with the connection unit flexible traction body. 2. A device for cleaning the inner surface of the tubing, including a connection unit to the flexible traction body, a weighting agent whose body is extended, and the lower end of the weighting body has a cone shape, identical scrapers mounted on a common rod at an equal distance from each other, moreover, the rod with the lower end is rigidly fixed to the upper end of the body of the weighting material, and the upper end is connected to the node connecting to the flexible traction body, while the longitudinal axial lines of the weighting body I, the rods and the attachment unit are the same, in addition, each scraper contains two identical in shape radial knives made in the form of an isosceles trapezoid, the sides of which are made by workers and have two-sided sharpening, and a cutter rigidly fixed to the smaller base of the trapezoid of the radial knife, radial knives are rigidly fixed with large trapezoid bases on the lateral surface of the rod at an angle of 90 ° to its surface, parallel to its longitudinal axial line, while the scrapers are deployed on the rod relative to each other, characterized in that the device comprises three scrapers in which the first and second radial knives are rotated 180 ° relative to each other and are rigidly fixed by large bases of trapeziums on the side surface of the rod symmetrically relative to its longitudinal axial line, and in the extreme scrapers there is a smaller base of the trapezoid of the first radial knives made by the worker and has a double-sided sharpening, in addition, the radial knives of the extreme scrapers lie in the same plane, while the radial knives of the same name with the extreme scrapers are spatially n are opposite relative to the longitudinal axial line of the rod, and the radial knives of the middle scraper are rotated 90 ° relative to the extreme ones; in addition, a cutter is rigidly fixed in the scrapers, which is two identical plates in the form of tapes with sharpening of both edges inward, the ends of which are connected to form a tip and rigidly fixed on the smaller bases of the trapezoid of the second radial knives of the extreme scrapers with the formation of an angle between them at which the working surface of the cutter plates is equidistant from the inner side surface of us a main-compressor pipe, while the middle part of the plates is mounted respectively on the smaller radial knife base of the middle scraper symmetrically with respect to the longitudinal axial line of the rod, in addition, the weighting body and the rod are hollow, while the rod is attached to the lower end of the weighting body with the formation of a common coaxial inner cavity and with the possibility of communication of the common internal cavity with the outer space at the junction of the rod with the node connecting to the flexible traction body.

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