A composite bearing casing centralizer

Abstract

The present invention belongs to the field of casing lowering equipment and facilities, and proposes a composite bearing type casing straightener, including a pair of sleeves and a plurality of elastic wing assemblies, wherein the sleeves include a sleeve body, an installation port, a welding positioning plate, an upper hoop and a lower hoop, and the elastic wing assembly includes an end piece, an inner spring sheet and an outer spring sheet, and a cantilever plate and an impeller group are arranged on the inner side of the inner spring sheet, and the axis of the impeller group faces the side of the inner spring sheet, and the inner spring sheet and the outer spring sheet are both double-bow structures and the bow directions of the two are opposite, and the inner spring sheet and the outer spring sheet are respectively provided with double-row balls and single-row balls on the side facing away from the center of the casing, and the double-row balls are used to support the outer spring sheet and reduce the friction in the direction of the casing lowering, and the single-row balls are used to reduce the friction in the direction of the casing lowering. The present invention has reasonable design, good wear resistance, good straightening effect, is conducive to promoting the circulation effect of the underground circulating medium, and can use the well environment to advance the progress of casing lowering, and is suitable for large-scale promotion.

Description

Technical Field

[0001] The invention belongs to the field of casing running equipment and facilities, and in particular relates to a composite bearing type casing centralizer. Background Art

[0002] During the casing lowering operation, there are elevators on the rig. After lowering one casing, the casing is stuck under the elevator. Lower another casing into the elevator, tighten the casing thread, loosen the elevator, and lower the casing again. This process is repeated until the casing reaches the designed layer. Casing lowering usually requires some downhole tools, such as centralizers, back pressure valves, guide shoes, etc. Centralizers are used to ensure that drilling tools, pipes, etc. are centered in the wellbore or trench.

[0003] Existing centralizers can generally be divided into rotary centralizers, wear-resistant coating centralizers, elastic centralizers and hydraulic centralizers. Among them, rotary centralizers and elastic centralizers are more commonly used. The former is a rotary centralizer, such as a casing centralizer disclosed in the existing patent CN201920630638.1. When the drill moves in the wellbore, the part of this type of centralizer in contact with the wellbore wall can rotate freely, converting sliding friction into rolling friction, reducing friction and wear; the latter is a casing elastic centralizer device disclosed in CN202021858952.4. When this type of centralizer passes through an irregular wellbore, a reduced diameter section or contacts the wellbore wall, these elastic fins can adaptively deform, buffer the rigid collision and friction between the wellbore wall, and reduce local stress concentration. However, the general rotary centralizer is weaker in the passability of complex well sections than the elastic centralizer, especially in complex well sections with reduced diameters, which are prone to drill jams. As for the elastic stabilizer, there are also some problems in its practical application. First, the main bearing force direction of the elastic stabilizer is radial. Since one end of the elastic stabilizer can slide along the casing body, the axial force it receives in the forward direction will also cause the elastic wing to deform. Although a certain straightening effect can be achieved, the wear and tear of the elastic wing is significantly increased, and the axial force and radial force received over this distance are difficult to evolve into axial thrust, which is not conducive to the advancement of the casing lowering progress; second, the centralizer moves downward with the casing in the opposite direction to the circulation direction of the drilling fluid outside the casing. The use of the centralizer will have a certain impact on the circulation of the drilling fluid, especially when encountering some small-sized wells, which will significantly interfere with the circulation of the drilling fluid, which may cause the bottom hole cuttings to fail to be carried out of the wellhead in time, and be repeatedly crushed by the working drill bit, reducing the drilling efficiency, and will also affect the cooling effect of the drilling fluid due to insufficient circulation, further accelerating the wear of the drill bit and shortening the service life of the drill bit. Summary of the invention

[0004] In view of the technical problems existing in the above-mentioned elastic centralizer, the present invention proposes a composite load-bearing casing centralizer with reasonable design, good wear resistance, good centralizing effect, conducive to promoting the circulation effect of underground circulating medium and capable of utilizing the wellbore environment to advance the progress of casing lowering.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is that a composite load-bearing casing centralizer provided by the present invention comprises a pair of hoops for being sleeved with the casing, the tightening ends of the hoops are provided with pin tubes and pins, a plurality of evenly distributed elastic wing assemblies are provided between the hoops, the hoops comprise a sleeve body, a plurality of mounting openings penetrating one end of the sleeve body are provided on the sleeve body, a welding positioning plate for fixing the elastic wing assembly is provided at the mounting opening, an upper tightening member is provided on the end of the sleeve body opposite to the mounting opening, a lower tightening member is provided on the sleeve body in the direction of the open end of the mounting opening, the lower tightening member is sequentially connected with a plurality of elastic wing assemblies, and the elastic wing assembly comprises a pair of hoops connected with two hoops The end pieces are connected respectively, and an inner spring sheet and an outer spring sheet are arranged between the end pieces, the end of the inner spring sheet is bent into a triangle, and the end of the outer spring sheet is bent and extended inwardly of the end of the outer spring sheet to form a C shape and is connected to the bent end of the inner spring sheet, a cantilever plate is arranged on the inner side of the inner spring sheet, and a pair of impeller groups are arranged on the cantilever plate, and the axis of the impeller group faces the side of the inner spring sheet, the inner spring sheet and the outer spring sheet are both double-bow structures and the bow directions of the two are opposite, the inner spring sheet and the outer spring sheet are respectively provided with a double row of balls and a single row of balls on the side facing away from the center of the casing, the double row of balls is used to support the outer spring sheet and reduce the friction in the direction of the lower casing, and the single row of balls is used to reduce the friction in the direction of the lower casing.

[0006] Preferably, the width of the inner spring sheet is greater than that of the outer spring sheet, the bent end of the inner spring sheet is provided with a transition opening, the transition opening is provided with a transition sheet connecting the inner spring sheet and the outer spring sheet, and the parts of the inner spring sheet located on both sides of the transition sheet are angular free ends.

[0007] Preferably, the maximum axial spacing between two impeller groups in the same pair is smaller than the width of the inner spring sheet, the impeller group comprises a wheel axle, the wheel axle cooperates with the shaft hole arranged on the cantilever plate, a circular shaft end plate is arranged at one end of the wheel axle, the shaft end plates of the two impeller groups are welded and rollingly cooperate with the wheel hole arranged in the middle of the cantilever plate, the other end of the wheel axle is provided with two impellers welded back to back, and the rotating surface of the impeller group is a double cone surface.

[0008] Preferably, the end piece is welded to the end of the inner spring sheet, and the end piece includes a pair of fins welded close to both sides of the inner spring sheet, the side of the fin facing away from the sleeve is a slope, and the fin is provided with a socket connected to the edge of the installation port, and the fin is also provided with a pair of T-shaped positioning ports for connecting with the welding positioning plate, the welding positioning plate is I-shaped and its plate body is a curved surface, and the side of the welding positioning plate is welded to the sleeve body.

[0009] Preferably, the upper hoop comprises two circles of O-shaped tubes spaced apart vertically and an upper hoop rope, the two ends of the upper hoop rope are inserted into one end of the two O-shaped tubes to form a U-shaped end, and the upper hoop rope is inserted into the other end of the two O-shaped tubes and is locked and connected with the U-shaped end.

[0010] Preferably, the lower hoop fastener comprises a plurality of broken tubes spaced apart from the mounting opening and a lower hoop rope, the broken tubes being used to correspond to the through holes provided on the inner spring sheet, and the two ends of the lower hoop rope are successively connected through the broken tubes and the through holes and are locked and connected at the passing-out ends.

[0011] Preferably, a wear-resistant alloy sheet is arranged on the outer side of the end of the inner spring sheet, and a ridge is formed in the middle of the wear-resistant alloy sheet toward the side facing away from the inner spring sheet to form a triangular structure.

[0012] Preferably, wear-resistant coatings are provided on both sides of the outer spring piece, the cross section of the wear-resistant coatings is U-shaped, and the U-shaped openings of the wear-resistant coatings on both sides of the outer spring piece are in opposite directions.

[0013] Compared with the prior art, the advantages and positive effects of the present invention are:

[0014] 1. The present invention provides a composite load-bearing casing centralizer. The inner and outer spring pieces of the elastic wing assembly can not only dynamically adjust the center position of the casing according to the radial force, but also bear the axial force, and convert the axial force it bears into thrust on the paired casing in the form of mutual extrusion deformation. In addition, part of the pressure can be converted into rolling friction through double-row balls and single-row balls, which is beneficial to the efficiency of advancing the casing while reducing friction and wear.

[0015] 2. The composite load-bearing casing straightener provided by the present invention can convert the pressure exerted by the drilling fluid on it into rotational power by using an impeller group near the connection position between the sleeve and the elastic wing assembly. The rotational power reacts on the drilling fluid, which is beneficial to improving the circulation efficiency of the drilling fluid, promoting the timely carrying of the bottom hole cuttings out of the wellhead, avoiding repeated crushing, and improving the drilling efficiency. To a certain extent, it is also beneficial to improve the cooling effect of the drilling fluid, reduce the wear of the drill bit, and ensure that the drill bit has a reasonable actual service life.

[0016] 3. The composite load-bearing casing centralizer provided by the present invention has reasonable design, good wear resistance, good centralizing effect, is beneficial to promoting the circulation effect of underground circulating medium and can utilize the well environment to advance the progress of casing lowering, and is suitable for large-scale promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A three-dimensional diagram of a composite load-bearing casing centralizer provided in an embodiment;

[0019] Figure 2 A working diagram of a composite load-bearing casing centralizer provided in an embodiment;

[0020] Figure 3 A schematic diagram of a composite load-bearing casing centralizer provided in an embodiment;

[0021] Figure 4 for Figure 1 A magnified schematic diagram of the structure in the middle;

[0022] Figure 5 A perspective view of a ferrule provided for an embodiment;

[0023] Figure 6 A perspective view of an elastic wing assembly provided for an embodiment;

[0024] Figure 7 for Figure 6 A magnified schematic diagram of structure B in the middle;

[0025] Figure 8 A schematic diagram of an elastic wing assembly provided in an embodiment;

[0026] Fig. 9 for Figure 8 A magnified schematic diagram of the C structure;

[0027] Fig.10 A perspective view of a pair of impeller assemblies provided in an embodiment;

[0028] Fig.11 A three-dimensional diagram of a welding positioning plate;

[0029] In the above figures: 1. ferrule; 11. pin tube; 12. sleeve body; 13. installation port; 14. welding positioning plate; 15. upper clamp; 151. O-type tube; 152. upper clamp rope; 153. U-shaped end; 16. lower clamp; 161. broken tube; 162. lower clamp rope; 2. elastic wing assembly; 21. end piece; 211. fin; 212. slope; 213. socket; 214. T-shaped positioning port; 22. inner spring piece; 221. transition port; 222. transition piece; 223. angular free end; 224. perforation; 23. outer spring piece; 24. cantilever plate; 25. double row ball bearings; 26. single row ball bearings; 27. wear-resistant alloy sheet; 28. wear-resistant coating; 3. impeller group; 31. wheel shaft; 32. shaft end plate; 33. impeller; 4. sleeve. DETAILED DESCRIPTION

[0030] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear below, they only indicate that the upper, lower, left and right directions are consistent with the accompanying drawings themselves, and do not limit the structure.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0032] Examples, such as Figure 1-Figure 11 As shown, the composite bearing casing centralizer provided by the present invention comprises a pair of hoops 1 for sleeved with the casing 4, the tightening ends of the hoops 1 are provided with pin tubes 11 and pins, and a plurality of uniformly distributed elastic wing assemblies 2 are provided between the hoops 1. Among them, the pin tubes 11 and the pins act as connecting hinges, and the hoops 1 are locked at both ends by the pin tubes 11 and the pins, thereby forming a closed sleeve 12 to cooperate with the casing 4, and the elastic wing assembly 2 is used as the main actuator for performing elastic deformation and straightening, and in order to improve the straightening effect of the elastic wing assembly 2 in the well, the present invention has made beneficial improvements to it.

[0033] Specifically, the sleeve hoop 1 provided by the present invention includes a sleeve body 12, and a plurality of mounting openings 13 penetrating one end of the sleeve body 12 are provided on the sleeve body 12, and a welding positioning plate 14 for fixing the elastic wing assembly 2 is provided at the mounting opening 13, and an upper clamping member 15 is provided on the end of the sleeve body 12 opposite to the mounting opening 13, and a lower clamping member 16 is provided on the sleeve body 12 at the open end direction of the mounting opening 13, and the lower clamping member 16 is sequentially connected with the plurality of elastic wing assemblies 2, and the elastic wing assembly 2 includes a pair of end pieces 21 respectively connected to the two sleeve hoops 1, and an inner spring piece 22 and an outer spring piece 23 are provided between the end pieces 21, and the axial center plane of the inner spring piece 22 and the axial center plane of the outer spring piece 23 are in the same plane, and the end of the inner spring piece 22 is bent into a triangle, and the end of the outer spring piece 23 is bent and extended to the inner side of the end of the outer spring piece 23 in a C shape and connected to the bent end of the inner spring piece 22 Then, a cantilever plate 24 is arranged on the inner side of the inner spring piece 22, and a pair of impeller groups 3 are arranged on the cantilever plate 24, and the axis of the impeller group 3 faces the side of the inner spring piece 22. The inner spring piece 22 and the outer spring piece 23 are both double-bow structures and the bow directions of the two are opposite. The double-bow structure refers to having two wave crest positions, the wave crests are connected by wave troughs, and the wave troughs of the outer spring piece 23 and the wave troughs of the inner spring piece 22 are in a state of mutual extrusion and contact under natural conditions, and the bow height of the outer spring piece 23 is greater than the bow height of the inner spring piece 22. The inner spring piece 22 and the outer spring piece 23 are respectively provided with a double row of balls 25 and a single row of balls 26 on the side facing away from the center of the sleeve 4. The balls arranged by the double row of balls 25 and the single row of balls 26 can rotate, and the double row of balls 25 are used to support the outer spring piece 23 and reduce the friction in the direction of the lower sleeve 4, and the single row of balls 26 are used to reduce the friction in the direction of the lower sleeve 4.

[0034] In the present invention, the tension of the sleeve 12 and the casing 4 is controlled by the upper tightening member 15 and the lower tightening member 16 by adjusting the actual diameters of the upper tightening member 15 and the lower tightening member 16, and the sleeve 12 and the casing 4 in the forward direction of the casing 4 are tightened, while the tension of the sleeve 12 and the casing 4 toward the rear side of the casing 4 can be loosened, so that the device can produce a certain extension along the direction of the casing 4 under load. However, the sleeve 12 and the casing 4 at this position need to maintain a certain friction pressure to ensure that the bent ends of the inner spring clip 22 and the outer spring clip 23 can produce a certain deformation, thereby playing a straightening role in the narrow shaft.

[0035] As for the elastic wing assembly 2, its two ends are fixed at the installation opening 13 of the sleeve body 12 through the cooperation of the end piece 21 and the welding positioning plate 14. Furthermore, the radial pressure on the path of the sleeve 4 and the straightener moving forward synchronously can be directly converted into the straightening pressure of the straightener. The deformation of a single elastic wing assembly 2 will cause changes in other elastic wing assemblies 2. Under the combined action of all elastic wing assemblies 2, the sleeve 4 can be kept in the center position of the well, that is, the straightening effect is played. Furthermore, the triangular structure formed by the bending of the end of the inner spring piece 22 can play the role of diversion, and can also play the role of wedging into the well in the process of contacting the narrow well, guiding the elastic structure behind to produce corresponding deformation. The maximum radial dimension of the triangular structure is smaller than the maximum radial dimension of the arch of the outer spring piece 23, and the inner spring piece 22 and the arched part of the outer spring piece 23 play the role of straightening and propulsion. For example, the arched part of the outer spring piece 23 can directly contact the well environment, and the well wall can apply pressure to it. The resulting changes are: the trough section of the outer spring piece 23 slides and deforms along the peak section on the rear side of the inner spring piece 22. Since the arched height of the outer spring piece 23 is greater than the arched height of the inner spring piece 22, that is, the deformation of the outer spring piece 23 The length is greater than that of the inner spring piece 22, so the trough section of the inner spring piece 22 squeezes the peak section of the front side of the outer spring piece 23 that is deformed to exert a reaction force, and the peak section of the outer spring piece 23 has a recovery trend; at the same time, the bending of the rear ends of the outer spring piece 23 and the inner spring piece 22 will be aggravated, thereby causing the front ends of the outer spring piece 23 and the inner spring piece 22 to generate a forward pulling force, thereby causing the outer spring piece 23 and the inner spring piece 22 to move toward the equilibrium position, thereby converting the axial pressure into a forward thrust on itself and the sleeve 4.

[0036] Therefore, the inner spring piece 22 and the outer spring piece 23 can not only dynamically adjust the center position of the casing 4 according to the radial force, but also bear the axial force, and convert the axial force they bear into the thrust of the paired casing 4 in the form of mutual extrusion deformation; the double-row ball 25 can reduce the friction between the outer spring piece 23 and the inner spring piece 22, and effectively support the outer spring piece 23, improve the instantaneity of the slip and deformation of the outer spring piece 23 along the crest section and trough section of the inner spring piece 22, and part of the pressure can be converted into rolling friction through the double-row ball 25 and the single-row ball 26, including the friction of the drilling fluid, which can promote the efficiency of the casing 4 on the basis of reducing friction and wear.

[0037] like Figure 1-Figure 4 As shown, the present invention can convert the pressure exerted by the drilling fluid on it into rotational power by using an impeller group 3 near the connection position between the sleeve hoop 1 and the elastic wing assembly 2. The rotational power reacts on the drilling fluid, which is beneficial to improving the circulation efficiency of the drilling fluid, promoting the bottom hole cuttings to be carried out of the wellhead in time, avoiding repeated crushing, and improving the drilling efficiency. To a certain extent, it is also beneficial to improve the cooling effect of the drilling fluid, reduce the wear of the drill bit, and ensure that the drill bit has a reasonable actual service life.

[0038] In order to improve the combined elastic performance of the inner spring piece 22 and the outer spring piece 23, the width of the inner spring piece 22 provided by the present invention is greater than the width of the outer spring piece 23, and a transition opening 221 is provided at the bent end of the inner spring piece 22. The transition opening 221 is provided with a transition piece 222 connecting the inner spring piece 22 and the outer spring piece 23, and the parts of the inner spring piece 22 located on both sides of the transition piece 222 are angular free ends 223. Among them, the outer spring piece 23 and the inner spring piece 22 can combine the elastic deformation of the ends of the two through the connection effect of the transition piece 222. For example, when the outer spring piece 23 is squeezed, the curvature of the C-shaped part at one end of the outer spring piece 23 increases, and the curved part pulls the transition piece 222 into its C-shaped curved path, and at the same time causes the angular free end 223 to be flattened along the mounting surface of the double-row balls 25 of the inner spring piece 22. During the flattening process, a recovery trend will be generated, thereby allowing the end of the elastic wing assembly 2 to maintain a corresponding elastic recovery ability; conversely, when the outer spring piece 23 is squeezed, the C-shaped part of the other end of the outer spring piece 23 can produce a certain amount of stretching, and the transition piece 222 will produce a certain extension along the stretched part of the outer spring piece 23, while the triangular part of the inner spring piece 22 will produce a certain elevation angle and generate a recovery tension, so that the elastic wing assembly 2 will also maintain a corresponding elastic recovery ability at this end.

[0039] like Figure 4-Figure 10 As shown, the maximum axial spacing between the two impeller groups 3 in the same pair is smaller than the width of the inner spring sheet 22, and the impeller group 3 includes a wheel shaft 31, which cooperates with the shaft hole set on the cantilever plate 24, and a circular shaft end plate 32 is set at one end of the wheel shaft 31. The shaft end plates 32 of the two impeller groups 3 are welded and rollingly cooperate with the wheel hole set in the middle of the cantilever plate 24, and two impellers 33 welded back to back are set at the other end of the wheel shaft 31, and the rotating surface of the impeller group 3 is a double cone surface. Among them, the wheel holes on the cantilever plate 24 can support the shaft end plates 32 of the two impellers 33; the impeller 33, the wheel shaft 31 and the shaft end plate 32 are welded, which can reduce mechanical connectors and improve the connection reliability of the impeller group 3 in the wellbore environment; the double cone surface of the impeller group 3 is smaller than the triangular range formed by the end of the inner spring sheet 22, and under the deformation condition of the elastic wing assembly 2, it also produces corresponding planar displacement with the cantilever plate 24, so that the impeller group 3 always maintains a certain rotation margin, so that the drilling fluid passing through this position in the wellbore can be thrown to the rear side of the drilling direction, thereby promoting the circulation of the drilling fluid.

[0040] like Figure 3 , Figure 4 , Figure 7 and Fig. 9As shown, the end piece 21 is welded to the end of the inner spring piece 22, and the end piece 21 includes a pair of fins 211 welded close to both sides of the inner spring piece 22, and the side of the fin 211 facing away from the sleeve 1 is a slope 212. The fin 211 is provided with a socket 213 plugged into the edge of the installation port 13, and the fin 211 is also provided with a pair of T-shaped positioning ports 214 for plugging with the welding positioning plate 14. The welding positioning plate 14 is I-shaped and its plate body is a curved surface. The side of the welding positioning plate 14 is welded to the sleeve body 12. Among them, the tail end of the T-shaped positioning port 214 faces away from the slope 212 and is connected with the side of the fin 211, which makes it easy to insert the welding positioning plate 14 into the fin; the fin 211 and the end of the inner spring plate 22 can form a guide surface for the drilling fluid, reducing the influence of the stabilizer on the casing 4 on the circulation performance of the drilling fluid; the end piece 21 forms a clamping relationship with the welding positioning plate 14 through the T-shaped positioning port 214, and the welding positioning plate 14 is welded to the sleeve 12, which can improve the connection quality between the end piece 21 and the sleeve 12; the socket 213 on the fin 211 increases the combination node of the end piece 21 and the sleeve 12, so that the mechanical force of the elastic wing assembly 2 on the welding positioning plate 14 can be transmitted to the casing 4, extending the welding node life of the welding positioning plate 14, thereby ensuring the connection reliability and service life of the hoop 1 and the elastic wing assembly 2.

[0041] like Figure 4 and Figure 5 As shown, the upper hoop 15 includes two circles of O-shaped tubes 151 spaced apart from each other and an upper hoop rope 152. The two ends of the upper hoop rope 152 penetrate from one end of the two O-shaped tubes 151 to form a U-shaped end 153. The upper hoop rope 152 penetrates from the other end of the two O-shaped tubes 151 and is locked and connected with the U-shaped end 153. The two O-shaped tubes 151 are clamped and pressed by the upper hoop rope 152, and two clamping pressure lines are formed on the sleeve 4 at the same time. As for the connection method between the U-shaped end 153 and the free end of the upper hoop rope 152, the present invention preferably adopts the method of bending the free end at the U-shaped end 153 and winding it 2-3 circles in a spring winding manner, and then welding or tying the two free ends.

[0042] Furthermore, considering the discontinuous characteristics of the installation opening 13 at the end of the sleeve body 12, the lower hoop 16 provided by the present invention includes a plurality of broken tubes 161 spaced apart from the installation opening 13 and a lower hoop rope 162. The broken tube 161 is used to correspond to the through hole 224 provided on the inner elastic sheet 22. The two ends of the lower hoop rope 162 are sequentially connected through the broken tube 161 and the through hole 224 and locked and connected at the end of the through hole. The broken tube 161 is a segmented design relative to the O-type tube; through the connection between the lower hoop rope 162 and the broken tube 161, it can not only form a corresponding locking relationship with the upper hoop 15, but also play a connecting role with the elastic wing assembly 2, so as to ensure the integrity of the sleeve hoop 1 and the elastic wing assembly 2, which is conducive to ensuring that the elastic wing assembly 2 can better play an elastic straightening role.

[0043] like Figure 4 As shown, a wear-resistant alloy sheet 27 is arranged outside the end of the inner spring piece 22, and a ridge is formed in the middle of the wear-resistant alloy sheet 27 toward the side facing away from the inner spring piece 22 to form a triangular structure. Considering that the outer side of the end of the inner spring piece 22 is a position prone to wear, the wear resistance of the end of the inner spring piece 22 can be improved by arranging the wear-resistant alloy sheet 27, and the ridged structure can form a slope 212 at this position of the drilling fluid, which is conducive to the rapid backward flow of the drilling fluid and reduces the number of frictions with the wear-resistant alloy sheet 27.

[0044] like Figure 3 and Figure 4 As shown, wear-resistant coatings 28 are provided on both sides of the outer spring piece 23. The cross-section of the wear-resistant coating 28 is U-shaped, and the U-shaped openings of the wear-resistant coatings 28 on both sides of the outer spring piece 23 are opposite to each other. The wear-resistant coatings 28 can improve the impact resistance and wear resistance of both sides of the outer spring piece 23, avoid erosion of the outer spring piece 23 during continuous movement, and help to ensure the period of edge integrity of the outer spring piece 23, thereby ensuring the elastic straightening performance of the elastic wing assembly 2.

[0045] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A composite load-bearing casing centralizer, comprising a pair of hoops for sleeve connection with the casing, wherein the tightening ends of the hoops are provided with a pin tube and a pin, and a plurality of evenly distributed elastic wing assemblies are provided between the hoops, characterized in that: The sleeve hoop comprises a sleeve body, a plurality of mounting openings penetrating one end of the sleeve body are arranged on the sleeve body, a welding positioning plate for fixing the elastic wing assembly is arranged at the mounting opening, an upper clamping member is arranged at the end of the sleeve body opposite to the mounting opening, a lower clamping member is arranged on the sleeve body in the open end direction of the mounting opening, the lower clamping member is sequentially connected with the plurality of elastic wing assemblies, the elastic wing assembly comprises a pair of end pieces respectively connected with two sleeve hoops, an inner spring sheet and an outer spring sheet are arranged between the end pieces, the end of the inner spring sheet is bent into a triangle, and the end of the outer spring sheet is bent toward the outer spring sheet. The inner side of the end portion is bent and extended into a C shape and connected to the bent end of the inner spring sheet. A cantilever plate is provided on the inner side of the inner spring sheet. A pair of impeller groups are provided on the cantilever plate. The axis of the impeller group faces the side of the inner spring sheet. The inner spring sheet and the outer spring sheet are both double-bow structures and the bow directions of the two are opposite. The inner spring sheet is provided with a double row of balls on the side facing away from the center of the casing, and the outer spring sheet is provided with a single row of balls on the side facing away from the center of the casing. The double row of balls is used to support the outer spring sheet and reduce the friction in the direction of the lower casing, and the single row of balls is used to reduce the friction in the direction of the lower casing; The width of the inner elastic sheet is greater than that of the outer elastic sheet, a transition opening is provided at the bent end of the inner elastic sheet, a transition sheet connecting the inner elastic sheet and the outer elastic sheet is provided at the transition opening, and the parts of the inner elastic sheet located on both sides of the transition sheet are angular free ends; The maximum axial spacing between the two impeller groups in the same pair is smaller than the width of the inner spring sheet. The impeller group includes a wheel axle, which cooperates with the shaft hole arranged on the cantilever plate. A circular shaft end plate is arranged at one end of the wheel axle. The shaft end plates of the two impeller groups are welded and rollingly cooperate with the wheel hole arranged in the middle of the cantilever plate. Two impellers welded back to back are arranged at the other end of the wheel axle, and the rotating surface of the impeller group is a double cone surface.

2. A composite bearing casing centralizer according to claim 1, characterized in that: The end piece is welded to the end of the inner spring sheet, and the end piece includes a pair of fins welded close to both sides of the inner spring sheet, the side of the fin facing away from the sleeve is a slope, and the fin is provided with a socket plugged into the edge of the installation port, and the fin is also provided with a pair of T-shaped positioning ports for plugging into the welding positioning plate, the welding positioning plate is I-shaped and its plate body is a curved surface, and the side of the welding positioning plate is welded to the sleeve body.

3. A composite bearing casing centralizer according to claim 1 or 2, characterized in that: The upper hoop fastener includes two circles of O-shaped tubes spaced apart from each other and an upper hoop rope, the two ends of the upper hoop rope are inserted from one end of the two O-shaped tubes to form a U-shaped end, and the upper hoop rope is inserted from the other end of the two O-shaped tubes and is locked and connected with the U-shaped end.

4. A composite bearing casing centralizer according to claim 3, characterized in that: The lower hoop fastener includes a plurality of broken tubes spaced apart from the installation opening and a lower hoop rope, wherein the broken tubes are used to correspond to the through holes set on the inner elastic sheet, and the two ends of the lower hoop rope are successively connected through the broken tubes and the through holes and locked at the through ends.

5. A composite bearing casing centralizer according to claim 1, characterized in that: A wear-resistant alloy sheet is arranged outside the end of the inner spring sheet, and a ridge is formed in the middle of the wear-resistant alloy sheet toward the side facing away from the inner spring sheet to form a triangular structure.

6. A composite bearing casing centralizer according to claim 1, characterized in that: Wear-resistant coatings are arranged on both sides of the outer spring piece, the cross section of the wear-resistant coatings is U-shaped, and the U-shaped openings of the wear-resistant coatings on both sides of the outer spring piece are opposite to each other.

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