CN217354290U - Non-rigid casing centralizer for well cementation - Google Patents

Abstract

The application provides a well cementation is with non-rigid casing centralizer, the casing centralizer includes: the core barrel is matched with the sleeve, and the centering barrel and the elastic piece are respectively sleeved on the core barrel; the core barrel comprises a barrel body and baffle ring assemblies respectively arranged at two ends of the barrel body, a buffer gap is formed between the centering barrel and the baffle ring assemblies, a rolling body is arranged on the outer wall surface of the barrel body, and the inner wall surface of the centering barrel is in contact with the surface of the rolling body; the outer wall surface of the righting cylinder is provided with a spiral guide rib, the elastic part is arranged in the buffer gap, and the elastic part can be respectively abutted against the righting cylinder and the baffle ring component, so that the righting cylinder can move along the axis of the cylinder under the action of external force received by the spiral guide rib and the action of elasticity of the elastic part. This application can be when guaranteeing that the sleeve pipe centralizer is to the effect of centering of sheathed tube right, avoids the damage that the sleeve pipe centralizer probably caused to the wall of a well to the at utmost, promotes the well cementation quality.

Description

Non-rigid casing centralizer for well cementation

Technical Field

The application relates to the technical field of oil and gas well cementation engineering equipment, in particular to a non-rigid casing centralizer for well cementation.

Background

Well cementation is an indispensable important link in the process of well drilling and completion operation, and comprises the steps of casing running, cementing, wellhead installation, casing pressure test and the like. The well cementing technology has the characteristics of systematicness, disposability and short time, and the main purpose of well cementing is to protect and support a casing in an oil-gas well and seal off oil, gas, water and other strata. The casing centralizer is a key device for improving cement cementing quality after a casing is put into a well, and has the functions of suspending, supporting, centralizing and centering the casing in an annular space of an open hole well wall, and sealing an oil gas water layer by means of cement cementing to enable the casing to be a channel for oil gas to flow into the well.

In the drilling and cementing process of a horizontal well or a large-inclination-angle inclined well, the casing can be directly attached to the well wall due to the self-weight of the casing, so that the cementing effect of cement is influenced, and certain hidden danger is caused for subsequent construction. Therefore, it is generally desirable to improve cement replacement efficiency by rotating and moving the casing up and down, thereby improving the quality of the cementing. Although the types of the existing casing centralizer are various, the common casing centralizer generally moves along with the casing, so that a centralizing bar on the casing centralizer can scratch the well wall, the well wall is easy to drop, and the well wall can be seriously collapsed; if the centralizer does not move along with the casing, sliding friction will be generated between the casing and the centralizer, and long-time relative movement will cause abrasion to the casing, thereby affecting the service life of the casing.

Based on this, the prior art discloses a patent No. CN215979246U with the name of a casing direct-connected rotatable elastic centralizer and elastic centralizing equipment, in which although an elastic centralizing cylinder can keep the casing at a central position, it does not rotate with a mandrel, and it does not impact the borehole wall; the core shaft and the sleeve rotate together, so that the abrasion to the sleeve is avoided, and the well cementation quality is improved. However, because the relative rotation between the dabber in this application and the elasticity righting section of thick bamboo is realized to adoption clearance fit's mode between, the centralizer of this kind of structure is at the practical application in-process, because of complicated well structure probably makes the contact take place between irregular wall of a well and the elasticity righting section of thick bamboo to cause and collide between the elasticity righting section of thick bamboo and the dabber, look for a long time, not only be unfavorable for the sleeve pipe right the effect of centering and improve, still can influence the life of centralizer self.

In addition, the prior art also has a patent number of CN214035566U, and the patent name is a controllable rotary centering device for improving the cementing quality of a horizontal well. The application provides a centralising apparatus which solves the above mentioned problems by providing a helical groove in sliding engagement with a guide pin to effect relative movement between the core tube and the centralising apparatus. However, in the centering device with the structure, the matching surface between the guide pin and the spiral groove is large, and the relative motion process of the guide pin and the spiral groove is not smooth in practice; and, along with the motion of sheathed tube, the uide pin can produce vertical or vertical shear force to the spiral groove, and this obviously can cause the influence to the structural strength of uide pin or spiral groove, is unfavorable for both structural stability's maintenance, and then also can influence righting device self life-span to a great extent. It will thus be seen that the prior art is susceptible to further improvement and enhancement.

SUMMERY OF THE UTILITY MODEL

The present application provides a non-rigid casing centralizer for well cementing to address at least one of the above technical problems.

The technical scheme adopted by the application is as follows:

the application provides a well cementation is with non-rigid casing centralizer, the casing centralizer includes: the core barrel is matched with the sleeve, and the centering barrel and the elastic piece are respectively sleeved on the core barrel; the core barrel comprises a barrel body and baffle ring assemblies respectively arranged at two ends of the barrel body, a buffer gap is formed between the righting barrel and the baffle ring assemblies, a rolling body is arranged on the outer wall surface of the barrel body, and the inner wall surface of the righting barrel is in contact with the surface of the rolling body; the outer wall surface of the righting cylinder is provided with a spiral guide rib, the elastic piece is arranged in the buffer gap and can be respectively abutted against the righting cylinder and the baffle ring assembly, so that the righting cylinder can move along the axis of the cylinder under the action of external force applied to the spiral guide rib and the elastic force of the elastic piece.

As a preferred embodiment of the present invention, the rolling element is composed of a plurality of balls, and the plurality of balls are uniformly distributed on the outer surface of the cylinder; or the rolling body consists of a plurality of balls, and the balls are spirally wound on the outer wall surface of the cylinder along the axial direction of the cylinder.

As a preferred embodiment of the present invention, the casing centralizer further comprises a holder, the core cylinder, the holder and the centralizer are sequentially nested among the three, and the outer surface of the holder forms the outer wall surface of the cylinder.

As an embodiment of the present invention, the spiral guiding ribs are multiple, and multiple parallel between the spiral guiding ribs.

As a preferred embodiment of the present invention, the outer wall surface of the straightening cylinder is further provided with a guide roller, a guide gap is formed between the plurality of spiral guide ribs, and the guide roller is disposed in the guide gap; and/or the surfaces of the plurality of spiral guide ribs are provided with guide rollers.

As a preferred embodiment of the present invention, the height of the spiral guide rib is greater than the height of the retainer ring assembly in the radial direction of the core barrel.

As a preferred embodiment of the present invention, the baffle ring assembly comprises an upper baffle ring disposed at the top end of the cylinder and a lower baffle ring disposed at the bottom end of the cylinder; the upper retaining ring and the lower retaining ring are both provided with internal threads, the barrel is provided with external threads, and the internal threads are matched with the external threads to realize the detachable connection between the retaining ring assembly and the barrel.

As a preferred embodiment of the present invention, the buffer gap includes a first sub-gap formed between the upper baffle ring and the righting cylinder, and a second sub-gap formed between the lower baffle ring and the righting cylinder, and the elastic member is located in the first sub-gap and/or the second sub-gap.

As an embodiment of the present invention, the upper end face and the lower end face of the righting cylinder are both provided with fixing grooves which can be matched with the elastic members.

As a preferred embodiment of the present invention, the retainer ring assembly is in interference fit with the cylinder.

Due to the adoption of the technical scheme, the technical effect obtained by the application is as follows:

1. the application provides a well cementation is with non-rigid casing centralizer makes whole equipment have the advantage of two kinds of centralizers of elasticity centralizer and rigidity centralizer concurrently through mutually supporting between core section of thick bamboo, a righting section of thick bamboo and the elastic component three to when guaranteeing that the casing centralizer is to the sheathed tube centralizing effect of placing in the middle, avoid the casing centralizer to promote the well cementation quality to the damage that the wall of a well probably caused in the at utmost. Specifically, this application makes the core section of thick bamboo and rights between the section of thick bamboo can sliding fit through the rolling element that sets up on the barrel outer wall, and this kind of cooperation mode is because the rolling element with right between the internal face of a section of thick bamboo point face contact, compare in the righting device that prior art provided in uide pin and helicla flute sliding fit's mode, undoubtedly can greatly reduced right the frictional force between section of thick bamboo and the core section of thick bamboo, do benefit to relative motion between the two, make this relative motion process more level and smooth. In addition, this kind of core section of thick bamboo and the mode of sliding fit between the section of thick bamboo of righting in this application makes core section of thick bamboo and right the possibility of rocking between the two through the rolling element, has avoided taking place to rock as far as possible between the two to not only guaranteed the centralizer to the sheathed tube centering effect, can also promote centralizer overall structure's stability and life. Moreover, this application sets up to a damping structure through the elastic component for relative motion between a core section of thick bamboo and the righting section of thick bamboo, on guaranteeing that both can carry out relative motion's basis, has reduced the impact of righting a section of thick bamboo to a core section of thick bamboo (especially keep off the ring subassembly) for the overall device still can keep better stability along with the in-process that the sleeve pipe moved.

2. As a preferred embodiment of the present invention, the rolling element is composed of a plurality of balls, and the plurality of balls can be uniformly distributed on the outer surface of the cylinder, or can be spirally wound on the outer surface of the cylinder along the axial direction of the cylinder. No matter which kind of above-mentioned mode of setting up, the homoenergetic is so that a core section of thick bamboo and right and keep good sliding fit between the section of thick bamboo, does benefit to the centralizer and rights the performance of effect placed in the middle. And, the mode that a plurality of ball equipartitions set up or spiral setting for both remain throughout at stable state between core section of thick bamboo and the righting section of thick bamboo, avoid appearing the condition of rocking because of clearance fit between the two to the at utmost.

3. As a preferred embodiment of the utility model, the setting of many spiral guide muscle can be in sheathed tube week, and the sleeve pipe that is arranged in the well carries out the omnidirectional guide and rights, and the guide clearance that forms between many spiral guide muscle can carry out the drainage to earth, grit etc to ensure the righting effect of centralizer. In addition, the setting of guide roll then can be on the basis of spiral guide rib, further promote the centering effect of centralizer to the right-hand member of sleeve pipe. Specifically, for the glide plane contact between spiral guide muscle and the wall of a well, and be the rolling surface contact between guide roll and the wall of a well, between the difference of both contact modes, set up through the guide roll and reduce the frictional force between a section of thick bamboo of rightting and the wall of a well to a certain extent to promote the sensitivity of centralizer to the sleeve pipe process of righting greatly.

4. As the utility model discloses an optimal implementation mode can adopt screw-thread fit's mode to dismantle between the barrel of fender ring subassembly and core section of thick bamboo and be connected, and this kind of connected mode can promote the convenience of assembly between each spare part of centralizer, reduces the assembly and the processing degree of difficulty of whole product to a certain extent, does benefit to product cost's reduction. On the other hand, can also adopt interference fit's mode to be connected between the barrel of fender ring subassembly and core section of thick bamboo, this kind of connected mode compares in screw-thread fit's connected mode, structurally makes the core section of thick bamboo become a complete whole, has promoted the structural strength of core section of thick bamboo self greatly to do benefit to and improve the stability of centralizer in the use, do benefit to product life's promotion.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation of the invention. In the drawings:

FIG. 1 is a schematic structural diagram of a casing centralizer according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of another casing centralizer provided in embodiments of the present application;

fig. 3 is a schematic structural diagram of a retainer provided in an embodiment of the present application;

FIG. 4 is a schematic structural diagram of another casing centralizer according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a core barrel provided in an embodiment of the present application.

Reference numerals:

100 core cylinders, 110 cylinder bodies, 120 baffle ring assemblies, 121 upper baffle rings, 122 lower baffle rings and 130 rolling bodies;

200 centralizing cylinders, 210 spiral guide ribs, 220 guide rollers and 221 guide rollers;

300 an elastic member;

400 cage.

Detailed Description

In order to more clearly explain the overall concept of the present application, the following detailed description is given by way of example in conjunction with the accompanying drawings.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, however, the present application may be practiced in other ways than those described herein, and therefore the scope of the present application is not limited by the specific embodiments disclosed below.

In addition, in the description of the present application, it is to be understood that the terms "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," and the like refer to orientations or positional relationships based on those illustrated in the drawings, merely to facilitate description of the application and to simplify description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered limiting of the present application.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; the connection can be mechanical connection, electrical connection or communication; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. In the description of the present specification, reference to the description of "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

As shown in fig. 1, the present application provides a non-rigid casing centralizer for cementing comprising a core barrel 100, a centralizer barrel 200, and a resilient member 300. Wherein, the core cylinder 100 is directly sleeved with the sleeve, and the righting cylinder 200 and the elastic element 300 are respectively sleeved outside the core cylinder 100. In addition, the core barrel 100 may include a barrel 110 and baffle ring assemblies 120 respectively disposed at two ends of the barrel 110, and a buffer gap (not labeled) is formed between the centering barrel 200 and the baffle ring assemblies 120; the outer wall surface of the cylinder 110 may be provided with a rolling body 130, and the inner wall surface of the straightening cylinder 200 may contact the surface of the rolling body 130.

Further, the outer wall surface of the righting cylinder 200 may be provided with a spiral guiding rib 210, the elastic member 300 is disposed in the buffer gap, and the elastic member 300 can be respectively abutted to the righting cylinder 200 and the baffle ring assembly 120, so that the righting cylinder 200 can move along the axis of the cylinder body 110 under the action of an external force applied to the spiral guiding rib 210 and the elastic force of the elastic member 300.

It should be understood that the present application is not limited to the specific size of the buffering gap, the buffering gap is set to provide enough movement space for the relative movement process between the core cylinder 100 and the righting cylinder 200, the size of the movement space or the size of the buffering gap defines the displacement amount of the core cylinder 100, and the specific size value depends on the relevant construction standard, the specification of the casing pipe, the design requirement of the product, and the like. In addition, regarding the specific structure or composition of the buffer gap, the present application is not limited, and the following contents in the specification of the present application will be expanded, and will not be described again here.

Furthermore, the centralizer provided by the application realizes the connection between the centralizer and the casing through the cooperation between the core barrel 100 and the casing. Due to the variety and size of the casing, such as surface casing, technical casing, reservoir casing, etc.; thus, the present application may also be variously sized with respect to the cartridge 100 to enable it to accommodate different sizes and types of ferrules.

In addition, the specific structure of the elastic member 300 is not limited in the present application, and may be a compression spring, or an elastic sheet or a rubber member having elastic deformation.

The application provides a well cementation is with non-rigid casing centralizer makes whole equipment have the advantage of two kinds of centralizers of elasticity centralizer and rigidity centralizer concurrently through mutually supporting between core section of thick bamboo 100, a righting section of thick bamboo 200 and the elastic component 300 three to when guaranteeing casing centralizer to the sheathed tube centralizing effect of centering, avoid the casing centralizer to the damage that the wall of a well probably caused in the at utmost, promote the well cementation quality.

Specifically, this application makes can sliding fit between core barrel 100 and the section of thick bamboo of righting 200 through the rolling element 130 that sets up on the barrel 110 outer wall, and this kind of cooperation mode is because the rolling element 130 contacts for the point face between the internal wall of the section of thick bamboo 200 of righting, compares in the mode that the guider pin and the helicla flute sliding fit among the righting device that prior art provided, can greatly reduced the frictional force between the section of thick bamboo 200 of righting and the core barrel 100, does benefit to relative motion between the two undoubtedly, makes this relative motion process more level and smooth. In addition, this kind of cartridge 100 and the mode of sliding fit between the section of thick bamboo 200 of righting in this application make cartridge 100 and the section of thick bamboo 200 between direct contact through rolling element 130, avoided taking place the possibility of rocking between the two as far as to not only guaranteed the centralizer to the sheathed tube effect of centering, can also promote centralizer overall structure's stability and life. Furthermore, a damping structure is additionally arranged on the relative movement between the core barrel 100 and the centering barrel 200 through the arrangement of the elastic part 300, so that on the basis of ensuring that the core barrel 100 and the centering barrel 200 can perform relative movement, the impact of the centering barrel 200 on the core barrel 100 (especially the baffle ring assembly 120) is reduced, and the whole device can still keep good stability in the movement process along with the casing.

With regard to the specific structure of the rolling elements 130 in the present application, two different embodiments will be described below.

Implementation mode one

Referring to fig. 1 and 2, the rolling body 130 in the present application may be composed of a plurality of balls, and the plurality of balls are uniformly distributed on the outer surface of the cylinder 110.

Second embodiment

The rolling element 130 in the present application is composed of a plurality of balls, and the plurality of balls are spirally wound on the outer wall surface of the cylinder 110 in the axial direction of the cylinder 110.

In the present application, the arrangement of the rolling elements 130, regardless of which embodiment is the above-mentioned, can keep a good sliding fit between the core barrel 100 and the centering barrel 200, and is beneficial to exerting the centering effect of the centralizer. And, the mode that a plurality of balls equipartition set up or spiral set up for both keep at stable state between core section of thick bamboo 100 and the section of thick bamboo 200 of righting all the time, avoid the condition of rocking to the at utmost because of clearance fit appears between the two. In the present application, the rolling elements 130 may be balls as shown in fig. 1 and 2, or needles, and the specific configuration of the rolling elements 130 is not limited.

In one embodiment, referring to fig. 3, the casing centralizer may further include a retainer 400, the cartridge 100, the retainer 400, and the centralizer 200 are sequentially nested with one another, and an outer surface of the retainer 400 forms an outer wall surface of the cylinder 110. The retainer 400 can provide a bearing base for the rolling body 130, so that the rolling body 130 is convenient to assemble, and the production and assembly difficulty of products is reduced. In addition, the manner of disposing the retainer 400 between the inner core barrel 100 and the outer centering barrel 200 also enables the retainer 400 to directly contact the elastic member 300, thereby providing stable support for the elastic member 300 and facilitating stable exertion of the damping effect of the elastic member 300.

In another embodiment, referring to fig. 1 and 2, the spiral guide rib 210 may be provided in a plurality of pieces, and the plurality of spiral guide ribs 210 are parallel to each other. The setting of many spiral guide muscle 210 can be in the sheathed tube week, and the sleeve pipe that lies in the well carries out the omnidirectional guide and rights, and the guide clearance that forms between many spiral guide muscle 210 can be to earth, grit etc. drainage to ensure the righting effect of centralizer.

The height of the spiral guide rib 210 is not limited in the present application. However, it will be appreciated that the dimensions should meet the following requirements: the height of the spiral guide rib 210 is greater than the height of the retainer ring assembly 120 in the radial direction of the cartridge 100. In other words, in the radial direction of the centralizer, the helical guide rib 210 should at least protrude beyond the slinger assembly 120 to achieve its initial contact with the wellbore wall.

Further, as shown in fig. 4, the outer wall surface of the righting cylinder 200 may further be provided with a guide roller 220, a guide gap (not marked in the figure) is formed between the plurality of spiral guide ribs 210, and the guide roller 220 is disposed in the guide gap; and/or, the surfaces of the plurality of spiral guide ribs 210 are provided with guide rollers 221.

The guide rollers 220 are arranged to further improve the centering effect of the centralizer on the casing on the basis of the spiral guide ribs 210. Specifically, for the slip surface contact between spiral guide muscle 210 and the wall of a well, and be the rolling surface contact between guide roll and the wall of a well, between the difference of both contact methods, can reduce the frictional force between righting section of thick bamboo 200 and the wall of a well to a certain extent through setting up guide roll 220 to promote the centralizer greatly and right the sensitivity of process to the sleeve pipe.

As a preferred embodiment of the present invention, referring to fig. 1 and 5, the retainer ring assembly 120 may include an upper retainer ring 121 disposed at the top end of the cylinder 110 and a lower retainer ring 122 disposed at the bottom end of the cylinder 110; moreover, the upper retaining ring 121 and the lower retaining ring 122 are both provided with internal threads (not shown in the figures), the cylinder body 110 is provided with external threads (not marked in the figures), and the internal threads and the external threads are matched with each other to realize the detachable connection between the retaining ring assembly 120 and the cylinder body 110.

The baffle ring assembly 120 and the cylinder body 110 of the core cylinder 100 can be detachably connected in a thread fit mode, the connection mode can improve the convenience of assembly among all parts of the centralizer, the assembly and processing difficulty of the whole product is reduced to a certain extent, and the reduction of the product cost is facilitated.

In addition, the retaining ring assembly 120 may be connected to the cartridge 100 by an interference fit, in addition to a threaded connection. Adopt interference fit's mode to be connected between the barrel 110 of fender ring subassembly 120 and core section of thick bamboo 100, this kind of connected mode compares in screw-thread fit's connected mode, structurally makes core section of thick bamboo 100 become a complete whole, has promoted the structural strength of core section of thick bamboo 100 self greatly to do benefit to and improve the stability of centralizer in the use, do benefit to product life's promotion.

In a preferred embodiment, with continued reference to fig. 1 and 2, the cushion gap may include a first sub-gap (not labeled) formed between the upper range ring 121 and the centering cylinder 200, and a second sub-gap (not labeled) formed between the lower range ring 122 and the centering cylinder 200, and the elastic member 300 is located in the first sub-gap and/or the second sub-gap.

Further, the upper end surface and the lower end surface of the righting cylinder 200 are both provided with fixing grooves (not shown in the figure) capable of being matched with the elastic member 300. The setting of fixed slot can carry on spacingly to elastic component 300, promotes the fixed effect of elastic component 300, prevents that elastic component 300 from producing the relative motion between core section of thick bamboo 100 and the righting section of thick bamboo 200 and interfering at the deformation in-process, promotes the stability of centralizer operation process.

Where not mentioned in this application, can be accomplished using or referencing existing technology.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims (10)

1. A non-rigid casing centralizer for cementing, the casing centralizer comprising: the core barrel is matched with the sleeve, and the centering barrel and the elastic piece are respectively sleeved on the core barrel;

the core barrel comprises a barrel body and baffle ring assemblies respectively arranged at two ends of the barrel body, a buffer gap is formed between the righting barrel and the baffle ring assemblies, a rolling body is arranged on the outer wall surface of the barrel body, and the inner wall surface of the righting barrel is in contact with the surface of the rolling body;

the outer wall surface of the righting cylinder is provided with a spiral guide rib, the elastic piece is arranged in the buffer gap and can be respectively abutted against the righting cylinder and the baffle ring assembly, so that the righting cylinder can move along the axis of the cylinder under the action of external force applied to the spiral guide rib and the elastic force of the elastic piece.

2. The non-rigid casing centralizer of claim 1, wherein the rolling body is comprised of a plurality of balls, and the plurality of balls are uniformly distributed on the outer surface of the cylinder; or the rolling body is composed of a plurality of balls, and the balls are spirally wound on the outer wall surface of the cylinder along the axial direction of the cylinder.

3. The non-rigid casing centralizer for well cementation according to claim 2, wherein the casing centralizer further comprises a retainer, the core barrel, the retainer and the centralizer are nested in sequence, and the outer surface of the retainer forms the outer wall surface of the barrel body.

4. The non-rigid casing centralizer for well cementation according to claim 1, wherein the spiral guide rib is provided in a plurality of parallel rows.

5. The centralizer of claim 4, wherein the centralizer is further provided with a guide roller on an outer wall surface of the centralizing cylinder, a plurality of spiral guide ribs form a guide gap therebetween, and the guide roller is arranged in the guide gap; and/or the surfaces of the plurality of spiral guide ribs are provided with guide rollers.

6. The non-rigid casing centralizer for well cementation according to claim 4, wherein the height of the spiral guide rib is greater than the height of the retainer ring assembly in a radial direction of the core barrel.

7. The non-rigid casing centralizer of claim 1, wherein the stop ring assembly comprises an upper stop ring disposed at the top end of the barrel and a lower stop ring disposed at the bottom end of the barrel;

the upper retaining ring and the lower retaining ring are both provided with internal threads, the barrel is provided with external threads, and the internal threads are matched with the external threads to realize the detachable connection between the retaining ring assembly and the barrel.

8. The non-rigid casing centralizer of claim 7, wherein the buffer gap comprises a first sub-gap formed between the upper retainer ring and the centralizer, and a second sub-gap formed between the lower retainer ring and the centralizer, and the resilient member is located in the first sub-gap and/or the second sub-gap.

9. The non-rigid casing centralizer for well cementation according to claim 8, wherein the upper end face and the lower end face of the centralizing cylinder are both provided with fixing grooves capable of being matched with the elastic part.

10. A non-rigid casing centralizer for cementing according to claim 1 wherein the retainer ring assembly is an interference fit with the barrel.

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