An adjustable casing centralizer and method of use

Abstract

The present application relates to the field of oil well cementing, in particular to a adjustable casing centralizer and method. The technical scheme is: the lower end of the first centralizer center pipe is connected with the second centralizer center pipe through the universal butt joint, the first centralizer sleeve is arranged below the first centralizer baffle, and the first outer joint sleeve is arranged between the first centralizer sleeve and the outer convex part of the universal butt joint; the second centralizer baffle is arranged on the outer side of the lower part of the second centralizer center pipe, the second centralizer sleeve is arranged on the upper side of the second centralizer baffle, the second outer joint sleeve is arranged between the second centralizer sleeve and the outer convex part of the universal butt joint, and a plurality of centralizer roller groups are installed on the outer walls of the first centralizer sleeve and the second centralizer sleeve. The present application not only has the centralizing function, but also makes the universal rotation spherical surface of the centralizer center pipe rotate around the outer joint sleeve spherical inner wall of the outer joint sleeve to form adjustable movable connection between every two groups of casings, so that the problems such as damage to the wellbore or resistance to casing running are avoided.

Description

Technical Field

[0001] This invention relates to the field of oil well cementing technology, and in particular to an adjustable casing centralizer and its usage method. Background Technology

[0002] Currently, with the rapid development of oil drilling and development technology, various complex wells such as deep wells, deviated wells, and horizontal wells have emerged. During cementing operations, it is necessary to connect the casing into a casing string and run it into the drilled wellbore. Then, cement is injected to carry out cementing operations, thereby firmly fixing the casing string in the wellbore. Then, subsequent perforation operations are carried out. This process requires that the inner wall of the drilled open hole not be damaged.

[0003] However, in current cementing operations, to improve the casing straightening effect and casing centering in deviated and horizontal wells, one or more casing straighteners are often installed on each casing to form a rigidly connected casing string. However, the excessive installation of existing casing straighteners can easily cause casing obstruction during installation, and in severe cases, casing installation accidents may occur. In addition, existing casing straighteners are installed on the outer wall of the casing and can only straighten the casing to the center of the wellbore, but cannot achieve omnidirectional turning. Therefore, the turning radius of the casing string is relatively large, and it often has to squeeze through the wellbore at the turning point, which can easily damage the wellbore or cause casing obstruction during installation, resulting in greater economic losses. Existing conventional pilot joints are not suitable for oilfield cementing operations and cannot meet the requirements for casing straightening.

[0004] Chinese patent application number CN202011572712.2, entitled "A Universal Wheel Sleeve Centralizer", includes a body in the shape of a cylinder. Several ribs are evenly arranged on the outer wall of the body, and several ball grooves are spaced apart on the ribs. Universal balls and mounting seats are installed in the ball grooves. The mounting seat includes a ring and several balls. The ring is installed at the bottom of the ball groove, and a groove is provided on the end face of the ring. The balls are movably installed in the groove. One end of the universal ball abuts against the ball, and the other end abuts against the opening of the ball groove. A portion of the universal ball spherically protrudes from the opening of the ball groove. This invention utilizes a mounting base to install the universal ball bearings within the ball bearing groove, allowing the universal ball bearings to rotate freely 360 degrees. This ensures the universal ball bearings do not fall out while preventing mud and sand from entering the ball bearing groove and affecting their rotation. The centralizer exhibits excellent friction reduction in all directions, ensuring uniform force and centering on the casing. However, it is still mounted on the outer wall of the casing and cannot achieve the turning function of the casing centralizer itself. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned deficiencies in existing technologies by providing an adjustable casing centralizer and its usage method. This invention is installed between every two casings, not only improving the centralizing effect and the casing's centering in the wellbore, but also allowing for limited adjustment and rotation of the central central tube around the spherical inner wall of the outer joint sleeve. This creates an adjustable, movable connection between the casings, avoiding serious problems such as wellbore damage to deviated or horizontal wells or obstruction during casing installation caused by rigidly connected casing strings, thus preventing greater economic losses.

[0006] The present invention discloses an adjustable sleeve centralizer, the technical solution of which includes a first centralizer tube, a first centralizer baffle, a first centralizer sleeve, a first outer joint sleeve, a universal joint, a centralizer roller assembly, a joint centralizer roller, a second centralizer tube, a second outer joint sleeve, a second centralizer sleeve, and a second centralizer baffle. The lower end of the first centralizer tube is movably connected to the second centralizer tube via the universal joint. A first centralizer baffle is provided on the upper outer side of the first centralizer tube, and below the first centralizer baffle... A first straightening sleeve is installed, and a first outer joint sleeve is installed between the first straightening sleeve and the outward protrusion of the universal joint; a second straightening baffle is provided on the lower outer side of the second straightening center tube, a second straightening sleeve is installed on the upper side of the second straightening baffle, and a second outer joint sleeve is installed between the second straightening sleeve and the outward protrusion of the universal joint; one or more straightening roller sets are evenly installed on the outer walls of the first and second straightening sleeves, and one or more joint straightening rollers are evenly installed on the outer walls of the first and second outer joint sleeves.

[0007] Preferably, the aforementioned first straightening center tube includes a center tube body, a universal rotating spherical surface, an elastic compensating rubber, a straightening baffle external thread, and a sleeve connection thread. One end of the center tube body is provided with a protruding universal rotating spherical surface, and an elastic compensating rubber is vulcanized on the outer end of the universal rotating spherical surface. The outer walls of the universal rotating spherical surface and the elastic compensating rubber slide in fit with the spherical inner wall of the outer joint sleeve of the first outer joint sleeve. An external thread for a straightening baffle is provided on the outer side of the other end near the center tube body for installing the first straightening baffle. A sleeve connection thread is provided on the outer wall of the outer end of the center tube body for threaded connection of the sleeve.

[0008] Preferably, the first external joint sleeve includes an external joint sleeve body, an external joint sleeve spherical inner wall, a sealing groove, and a body connecting thread. The external joint sleeve body has a cylindrical structure. An external joint sleeve spherical inner wall is provided on the upper side of the inner cavity of the external joint sleeve body, and a sealing groove is provided on the upper side of the external joint sleeve spherical inner wall. A body connecting thread is provided on the lower side of the inner cavity of the external joint sleeve body for threaded connection with a universal joint connector.

[0009] Preferably, the upper end of the inner cavity of the outer joint sleeve body is provided with an arc-shaped chamfer to improve the degree of freedom of rotation of the central tube body; the lower part of the inner cavity of the outer joint sleeve body is provided with a sealing surface that mates with the universal joint.

[0010] Preferably, the outer diameter of the central tube body is smaller than the inner diameter of the upper part of the inner cavity of the outer joint sleeve body, and the outer diameter of the universal rotating spherical surface is smaller than the inner diameter of the spherical inner wall of the outer joint sleeve. The universal rotating spherical surface sits inside the spherical inner wall of the outer joint sleeve and achieves universal sliding fit.

[0011] Preferably, the universal joint includes an upper connector body, an outward protrusion, an upper external thread, a lower connector body, and a lower external thread. The outward protrusion is provided between the upper connector body and the lower connector body. An upper external thread is provided on the outer wall of the upper connector body, and a lower external thread is provided on the outer wall of the lower connector body.

[0012] Preferably, the first straightening sleeve includes a straightening sleeve body and multiple sets of straightening rollers. Multiple sets of straightening rollers are evenly installed on the outer wall of the straightening sleeve body. Each set of straightening rollers includes a straightening sleeve roller, a roller shaft, and a roller support frame. The roller shaft is installed in the roller support frame, and the straightening sleeve roller is installed on the roller shaft through a bearing.

[0013] Preferably, biased bearing sleeves are installed on both sides of the straightening sleeve roller, and multiple biased bearing balls are installed on both end faces of the biased bearing sleeves.

[0014] The method of using the adjustable sleeve centralizer mentioned in this invention includes the following steps:

[0015] I. Assembling the Adjustable Sleeve Straightener: First, pass the main body of the first straightening center tube through the upper inner cavity of the main body of the first outer joint sleeve, and allow the universal spherical surface to sit inside the spherical inner wall of the outer joint sleeve to achieve universal sliding fit; then, put the first straightening sleeve on the main body of the center tube above the first outer joint sleeve, and then connect the first straightening baffle to the external thread of the straightening baffle through a thread, thereby installing the first straightening sleeve between the first outer joint sleeve and the first straightening baffle; then, connect the lower part of the first outer joint sleeve to the upper connector body of the universal joint through the main body connecting thread; then, connect the second straightening center tube to the second outer joint sleeve, connect the second outer joint sleeve to the lower part of the universal joint, and then install the second straightening sleeve and the second straightening baffle on the lower side of the second straightening center tube to complete the assembly of the adjustable sleeve straightener;

[0016] 2. An adjustable casing centralizer is connected between every two casings. Casings equipped with the adjustable casing centralizer are sequentially lowered from the surface wellhead. After the lower casing passes the wellbore's turning point, it enters the inclined section. This causes the connected adjustable casing centralizer's second centralizing tube to be compressed by the inclined section well wall. The central tube body, positioned at an arc-shaped chamfer, increases the rotational freedom of the central tube body. With the universal rotating spherical surface sitting within the spherical inner wall of the outer joint sleeve and achieving universal sliding cooperation, the universal rotating spherical surface of the second centralizing tube rotates around the second outer joint sleeve. The spherical inner wall of the outer joint sleeve rotates in a limited manner, thereby forming an adjustable movable connection between the upper and lower casings. With the straightening action of the straightening rollers on the second and first straightening sleeves and the joint straightening rollers on the second and first outer joint sleeves, the upper casing is smoothly lowered into the inclined and horizontal sections. Then, other connected casings are lowered in sequence, and finally the lower casing is smoothly lowered into the inclined and horizontal sections of the well. Then, the subsequent cementing process is carried out to fix the casing string in the wellbore, completing the cementing operation.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The adjustable casing centralizer of this invention is installed between casings. When the movable casing string passes through the turning point of the deviated or horizontal well, the universal rotating spherical surface sits on the inner wall of the outer joint sleeve and slides in all directions. This allows the universal rotating spherical surface of the central casing to rotate within a limited range around the inner wall of the outer joint sleeve, thereby forming an adjustable movable connection between the upper and lower casings. This avoids the problems of damage to the open hole well wall or obstruction during casing lowering caused by the hard connection of the casing string in the prior art. The adjustment range is determined by the length of the elastic compensation rubber. Different models are formed by setting different lengths of elastic compensation rubber and different curvatures of universal rotating spherical surface, which can meet the cementing needs of different deviated and horizontal wells. It can achieve a certain degree of turning angle, making it similar to the effect of a train carriage turning on a train track.

[0019] In addition, with the straightening action of the straightening rollers on the two straightening sleeves and the joint straightening rollers on the two outer joint sleeves, the present invention can smoothly realize the casing string being lowered into the horizontal section of the wellbore, improving the straightening effect and centering of the casing. Moreover, it is equipped with a liquid passage groove, which can complete the cementing operation by injecting cement between the casing and the open hole wall, thus meeting the function and requirements of the casing straightener. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2This is a schematic diagram of the structure of the first central straightening tube;

[0022] Figure 3 This is a schematic diagram of the structure of the first external joint sleeve;

[0023] Figure 4 This is a schematic diagram of the universal joint structure;

[0024] Figure 5 This is a top view structural diagram of one embodiment of the first straightening sleeve;

[0025] Figure 6 This is a top view of the structure of the second embodiment of the first straightening sleeve;

[0026] Figure 7 This is a schematic diagram illustrating the application of the present invention;

[0027] In the diagram: 1. First straightening baffle; 2. First straightening sleeve; 3. First outer joint sleeve; 4. Universal connector; 5. First straightening central tube; 6. Straightening roller assembly; 7. Connector straightening wheel; 8. Second straightening central tube; 9. Second outer joint sleeve; 10. Second straightening sleeve; 11. Second straightening baffle; 12. Sleeve; 13. Adjustable sleeve straightener; 14. Inclined section; 15. Horizontal section; 2.1 Straightening sleeve body; 2.2 Straightening sleeve roller; 2.3 Roller shaft; 2.4 Offset bearing sleeve; 2.5 Offset bearing ball. 2.6 Roller support frame, 2.7 Liquid passage area, 3.1 Outer joint sleeve body, 3.2 Spherical inner wall of outer joint sleeve, 3.3 Sealing groove, 3.4 Main body connection thread, 3.5 Arc chamfer, 3.6 Sealing surface, 4.1 Upper connector body, 4.2 Outer protrusion, 4.3 Upper external thread, 4.4 Lower connector body, 4.5 Lower external thread, 5.1 Central tube body, 5.2 Universal rotating spherical surface, 5.3 Elastic compensation rubber, 5.4 Straightening baffle external thread, 5.5 Sleeve connection thread. Detailed Implementation

[0028] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0029] Example 1, referring to Figures 1-5 and Figure 7The present invention discloses an adjustable sleeve straightener, comprising a first straightening central tube 5, and further comprising a first straightening baffle 1, a first straightening sleeve 2, a first outer joint sleeve 3, a universal joint 4, a straightening roller assembly 6, a joint straightening roller 7, a second straightening central tube 8, a second outer joint sleeve 9, a second straightening sleeve 10, and a second straightening baffle 11. The lower end of the first straightening central tube 5 is movably connected to the second straightening central tube 8 via the universal joint 4. A first straightening baffle 1 is provided on the upper outer side of the first straightening central tube 5, and a first straightening sleeve is installed below the first straightening baffle 1. 2. A first outer joint sleeve 3 is installed between the first straightening sleeve 2 and the outer protrusion 4.2 of the universal joint 4; a second straightening baffle 11 is provided on the lower outer side of the second straightening center tube 8; a second straightening sleeve 10 is installed on the upper side of the second straightening baffle 11; a second outer joint sleeve 9 is installed between the second straightening sleeve 10 and the outer protrusion 4.2 of the universal joint 4; one or more straightening roller sets 6 are evenly installed on the outer walls of the first straightening sleeve 2 and the second straightening sleeve 10; and one or more joint straightening rollers 7 are evenly installed on the outer walls of the first outer joint sleeve 3 and the second outer joint sleeve 9.

[0030] Reference Figure 2 The first straightening center tube 5 mentioned in this invention includes a center tube body 5.1, a universal rotating spherical surface 5.2, an elastic compensating rubber 5.3, a straightening baffle external thread 5.4, and a sleeve connection thread 5.5. One end of the center tube body 5.1 is provided with a protruding universal rotating spherical surface 5.2, and the elastic compensating rubber 5.3 is vulcanized on the outer end of the universal rotating spherical surface 5.2 to form an integral structure and reduce leakage. The outer walls of the universal rotating spherical surface 5.2 and the elastic compensating rubber 5.3 slide in fit with the spherical inner wall 3.2 of the outer joint sleeve 3. The other end near the center tube body 5.1 is provided with a straightening baffle external thread 5.4 for installing the first straightening baffle 1, and the outer wall of the outer end of the center tube body 5.1 is provided with a sleeve connection thread 5.5 for threaded connection of the sleeve 12.

[0031] Reference Figure 3 The first external joint sleeve 3 mentioned in this invention includes an external joint sleeve body 3.1, an external joint sleeve spherical inner wall 3.2, a sealing groove 3.3, and a main body connecting thread 3.4. The external joint sleeve body 3.1 has a cylindrical structure. The external joint sleeve spherical inner wall 3.2 is provided on the upper side of the inner cavity of the external joint sleeve body 3.1. The upper side of the external joint sleeve spherical inner wall 3.2 is provided with a sealing groove 3.3. A sealing ring is placed in the sealing groove 3.3, which achieves a better sealing effect. The main body connecting thread 3.4 is provided on the lower side of the inner cavity of the external joint sleeve body 3.1 for threaded connection with the universal joint 4.

[0032] Among them, the upper end of the inner cavity of the outer joint sleeve body 3.1 is provided with an arc-shaped chamfer 3.5 to improve the rotational freedom of the central tube body 5.1; the lower part of the inner cavity of the outer joint sleeve body 3.1 is provided with a sealing surface 3.6 that mates with the universal joint 4, thereby improving the sealing effect; and the outer side of the outer joint sleeve body 3.1 is evenly distributed with fluid grooves to facilitate the smooth passage of cementing mud.

[0033] In addition, the outer diameter of the central tube body 5.1 is smaller than the inner diameter of the upper part of the inner cavity of the outer joint sleeve body 3.1, and the outer diameter of the universal rotating spherical surface 5.2 is smaller than the inner diameter of the spherical inner wall 3.2 of the outer joint sleeve. The universal rotating spherical surface 5.2 sits inside the spherical inner wall 3.2 of the outer joint sleeve and achieves universal sliding fit.

[0034] Reference Figure 4 The universal joint 4 mentioned in this invention includes an upper joint body 4.1, an outward protrusion 4.2, an upper external thread 4.3, a lower joint body 4.4, and a lower external thread 4.5. The outward protrusion 4.2 is provided between the upper joint body 4.1 and the lower joint body 4.4. The outward protrusion 4.2 is evenly provided with multiple fluid passage grooves to facilitate the smooth entry of cementing mud. The upper external thread 4.3 is provided on the outer wall of the upper joint body 4.1, and the lower external thread 4.5 is provided on the outer wall of the lower joint body 4.4.

[0035] Reference Figure 5 The first straightening sleeve 2 mentioned in this invention includes a straightening sleeve body 2.1 and four sets of straightening rollers 6. The four sets of straightening rollers 6 are provided on the outer wall of the straightening sleeve body 2.1. The gap between the four sets of straightening rollers 6 is the liquid passage area 2.7, which facilitates the smooth introduction of cementing. Each set of straightening rollers 6 includes a straightening sleeve roller 2.2, a roller shaft 2.3, an bias bearing sleeve 2.4, a bias bearing ball 2.5, and a roller support frame 2.6. The roller shaft 2.3 is installed in the roller support frame 2.6, and the straightening sleeve roller 2.2 is installed on the roller shaft 2.3 through bearings.

[0036] Among them, biased bearing sleeves 2.4 are installed on both sides of the aforementioned straightening sleeve roller 2.2, and multiple biased bearing balls 2.5 are installed on both ends of the biased bearing sleeve 2.4, which can prevent the straightening sleeve roller 2.2 from seizing under compression.

[0037] The method of using the adjustable sleeve centralizer mentioned in this invention includes the following steps:

[0038] I. Assembling the Adjustable Sleeve Straightener: First, pass the central tube body 5.1 of the first straightening central tube 5 through the upper inner cavity of the outer joint sleeve body 3.1 of the first outer joint sleeve 3, and allow the universal rotating spherical surface 5.2 to sit within the spherical inner wall 3.2 of the outer joint sleeve, achieving a universal sliding fit; then, place the first straightening sleeve 2 onto the central tube body 5.1 above the first outer joint sleeve 3, and then connect the first straightening baffle 1 to the external thread 5.4 of the straightening baffle via threads, thereby adjusting the first straightening sleeve body 5.1. The positive sleeve 2 is installed between the first outer joint sleeve 3 and the first straightening baffle 1; then, the lower part of the first outer joint sleeve 3 is connected to the upper connector body 4.1 of the universal joint 4 through the main body connecting thread 3.4; then, the second straightening center tube 8 is connected to the second outer joint sleeve 9, the second outer joint sleeve 9 is connected to the lower part of the universal joint 4, and the second straightening sleeve 10 and the second straightening baffle 11 are installed on the lower side of the second straightening center tube 8 to realize the assembly of the adjustable sleeve straightener 13;

[0039] II. Reference Figure 7 An adjustable casing stabilizer 13 is connected between every two casings 12. Casings 12 equipped with the adjustable casing stabilizer 13 are sequentially lowered from the surface wellhead. After the lower casing 12 passes the wellbore's turning point, it enters the inclined section 14. This causes the second stabilizing central tube 8 of the connected adjustable casing stabilizer 13 to be compressed by the well wall of the inclined section 14. The central tube body 5.1, positioned at the arc-shaped chamfer 3.5, increases the rotational freedom of the central tube body 5.1. With the universal rotating spherical surface 5.2 sitting within the spherical inner wall 3.2 of the outer joint sleeve and achieving universal sliding cooperation, the universal rotating spherical surface 5.2 of the second stabilizing central tube 8 can rotate within a limited range around the spherical inner wall 3.2 of the second outer joint sleeve 9. This allows the upper casing 12 and the lower casing 12 to form an adjustable movable connection. The range of motion is determined by the length of the elastic compensation rubber 5.3. The well casing is typically configured with different lengths of elastic compensation rubber 5.3 and different curvatures of omnidirectional rotating spherical surfaces 5.2 to meet the requirements of different turning radii in the well. It is adjusted according to the well depth to achieve an effect similar to a train carriage turning on a railway track. Furthermore, under the corrective action of the corrective rollers 2.2 on the second corrective sleeve 10 and the first corrective sleeve 2, as well as the corrective rollers 7 on the joints of the second outer joint sleeve 9 and the first outer joint sleeve 3, the upper casing 12 is smoothly lowered into the inclined section 14 and the horizontal section 15. Then, other connected casings 12 are sequentially lowered, ultimately allowing the lower casing 12 to smoothly enter the inclined section 14 and the horizontal section 15 in the well. This invention reduces damage to the open hole wellbore and avoids potential obstruction during casing lowering. Then, cement is injected to fix the casing string in the wellbore, completing the cementing operation.

[0040] Example 2: An adjustable sleeve straightener mentioned in this invention includes a first straightening central tube 5, and further includes a first straightening baffle 1, a first straightening sleeve 2, a first outer joint sleeve 3, a universal joint 4, a straightening roller assembly 6, a joint straightening roller 7, a second straightening central tube 8, a second outer joint sleeve 9, a second straightening sleeve 10, and a second straightening baffle 11. The lower end of the first straightening central tube 5 is movably connected to the second straightening central tube 8 via the universal joint 4. A first straightening baffle 1 is provided on the upper outer side of the first straightening central tube 5, and a first straightening roller is installed below the first straightening baffle 1. The first straightening sleeve 2 is installed between the first straightening sleeve 2 and the outer protrusion 4.2 of the universal joint 4; a second straightening baffle 11 is provided on the lower outer side of the second straightening center tube 8; a second straightening sleeve 10 is installed on the upper side of the second straightening baffle 11; a second outer joint sleeve 9 is installed between the second straightening sleeve 10 and the outer protrusion 4.2 of the universal joint 4; one or more straightening roller groups 6 are evenly installed on the outer walls of the first straightening sleeve 2 and the second straightening sleeve 10; and one or more joint straightening rollers 7 are evenly installed on the outer walls of the first outer joint sleeve 3 and the second outer joint sleeve 9.

[0041] The difference from Example 1 is:

[0042] Reference Figure 6 The first straightening sleeve 2 mentioned in this invention includes a straightening sleeve body 2.1 and six sets of straightening rollers 6. The six sets of straightening rollers 6 are evenly installed on the outer wall of the straightening sleeve body 2.1. The gap between every two sets of straightening rollers 6 is a liquid passage area 2.7, which facilitates the smooth introduction of cementing. Each set of straightening rollers 6 includes a straightening sleeve roller 2.2, a roller shaft 2.3, a biased bearing sleeve 2.4, a biased bearing ball 2.5, and a roller support frame 2.6. The roller shaft 2.3 is installed in the roller support frame 2.6. The straightening sleeve roller 2.2 is installed on the roller shaft 2.3 through bearings. The biased bearing sleeve 2.4 is installed on both sides of the straightening sleeve roller 2.2. Multiple biased bearing balls 2.5 are installed on the two end faces of the biased bearing sleeve 2.4, which can prevent the straightening sleeve roller 2.2 from seizing under compression.

[0043] The above description is merely a partial preferred embodiment of the present invention. Any person skilled in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, any simple modifications or equivalent transformations made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. An adjustable sleeve centralizer, comprising a first centralizing tube (5), characterized in that: It also includes a first straightening baffle (1), a first straightening sleeve (2), a first outer joint sleeve (3), a universal joint (4), a straightening roller assembly (6), a joint straightening wheel (7), a second straightening central tube (8), a second outer joint sleeve (9), a second straightening sleeve (10), and a second straightening baffle (11). The lower end of the first straightening central tube (5) is movably connected to the second straightening central tube (8) through the universal joint (4). A first straightening baffle (1) is provided on the upper outer side of the first straightening central tube (5). A first straightening sleeve (2) is installed below the first straightening baffle (1). The first straightening sleeve (2) is connected to the universal joint. (4) The first outer joint sleeve (3) is installed between the outer protrusion (4.2); the second straightening baffle (11) is provided on the lower outer side of the second straightening center tube (8); the second straightening sleeve (10) is installed on the upper side of the second straightening baffle (11); the second outer joint sleeve (9) is installed between the second straightening sleeve (10) and the outer protrusion (4.2) of the universal joint (4); one or more straightening roller groups (6) are evenly installed on the outer walls of the first straightening sleeve (2) and the second straightening sleeve (10); one or more joint straightening rollers (7) are evenly installed on the outer walls of the first outer joint sleeve (3) and the second outer joint sleeve (9). The first straightening center tube (5) includes a center tube body (5.1), a universal rotating spherical surface (5.2), an elastic compensating rubber (5.3), a straightening baffle external thread (5.4), and a sleeve connection thread (5.5). One end of the center tube body (5.1) is provided with a protruding universal rotating spherical surface (5.2). An elastic compensating rubber (5.3) is vulcanized on the outer end of the universal rotating spherical surface (5.2). The outer walls of the universal rotating spherical surface (5.2) and the elastic compensating rubber (5.3) slide in fit with the spherical inner wall (3.2) of the outer joint sleeve of the first outer joint sleeve (3). A straightening baffle external thread (5.4) is provided on the outer side of the other end near the center tube body (5.1) for installing the first straightening baffle (1). A sleeve connection thread (5.5) is provided on the outer wall of the outer end of the center tube body (5.1) for threaded connection of the sleeve (12).

2. The adjustable casing centralizer according to claim 1, characterized in that: The first external joint sleeve (3) includes an external joint sleeve body (3.1), an external joint sleeve spherical inner wall (3.2), a sealing groove (3.3), and a main body connecting thread (3.4). The external joint sleeve body (3.1) is a cylindrical structure. An external joint sleeve spherical inner wall (3.2) is provided on the upper side of the inner cavity of the external joint sleeve body (3.1), and a sealing groove (3.3) is provided on the upper side of the external joint sleeve spherical inner wall (3.2). A main body connecting thread (3.4) is provided on the lower side of the inner cavity of the external joint sleeve body (3.1) for threaded connection with the universal joint (4).

3. The adjustable casing centralizer according to claim 2, characterized in that: The upper end of the inner cavity of the outer joint sleeve body (3.1) is provided with an arc-shaped chamfer (3.5) to improve the rotational freedom of the central tube body (5.1); the lower part of the inner cavity of the outer joint sleeve body (3.1) is provided with a sealing surface (3.6) that cooperates with the universal joint (4).

4. The adjustable casing centralizer according to claim 3, characterized in that: The outer diameter of the central tube body (5.1) is smaller than the inner diameter of the upper part of the inner cavity of the outer joint sleeve body (3.1), and the outer diameter of the universal rotating spherical surface (5.2) is smaller than the inner diameter of the spherical inner wall (3.2) of the outer joint sleeve. The universal rotating spherical surface (5.2) sits inside the spherical inner wall (3.2) of the outer joint sleeve and achieves universal sliding fit.

5. The adjustable casing centralizer according to claim 4, characterized in that: The universal joint (4) includes an upper joint body (4.1), an outward protrusion (4.2), an upper external thread (4.3), a lower joint body (4.4), and a lower external thread (4.5). The outward protrusion (4.2) is provided between the upper joint body (4.1) and the lower joint body (4.4). The upper external thread (4.3) is provided on the outer wall of the upper joint body (4.1), and the lower external thread (4.5) is provided on the outer wall of the lower joint body (4.4).

6. The adjustable casing centralizer according to claim 5, characterized in that: The first straightening sleeve (2) includes a straightening sleeve body (2.1) and multiple sets of straightening rollers (6). Multiple sets of straightening rollers (6) are evenly installed on the outer wall of the straightening sleeve body (2.1). Each set of straightening rollers (6) includes a straightening sleeve roller (2.2), a roller shaft (2.3), and a roller support frame (2.6). The roller shaft (2.3) is installed inside the roller support frame (2.6), and the straightening sleeve roller (2.2) is installed on the roller shaft (2.3) through a bearing.

7. The adjustable casing centralizer according to claim 6, characterized in that: in The straightening sleeve roller (2.2) is equipped with bias bearing sleeves (2.4) on both sides, and multiple bias bearing balls (2.5) are installed on both ends of the bias bearing sleeve (2.4).

8. The method of using the adjustable casing centralizer according to claim 7, characterized in that: The process includes the following: I. Assembling the Adjustable Tube Straightener: First, pass the central tube body (5.1) of the first straightening central tube (5) through the upper inner cavity of the outer joint sleeve body (3.1) of the first outer joint sleeve (3), and make the universal rotating spherical surface (5.2) sit in the spherical inner wall (3.2) of the outer joint sleeve and achieve universal sliding fit; then, put the first straightening sleeve (2) on the central tube body (5.1) above the first outer joint sleeve (3), and then connect the first straightening baffle (1) to the external thread (5.4) of the straightening baffle through thread, thereby adjusting the first straightening sleeve (2) The first outer joint sleeve (3) is installed between the first outer joint sleeve (3) and the first straightening baffle (1); then, the lower part of the first outer joint sleeve (3) is connected to the upper connector body (4.1) of the universal connector (4) through the main body connecting thread (3.4); then, the second straightening center tube (8) is connected to the second outer joint sleeve (9), the second outer joint sleeve (9) is connected to the lower part of the universal connector (4), and the second straightening sleeve (10) and the second straightening baffle (11) are installed on the lower side of the second straightening center tube (8) to realize the assembly of the adjustable sleeve straightening device (13); 2. An adjustable casing stabilizer (13) is connected between every two casings (12). Casings (12) equipped with adjustable casing stabilizers (13) are sequentially lowered from the surface wellhead. After the lower casing (12) passes the wellbore's turning point, it enters the inclined section (14). This causes the second stabilizing central tube (8) of the connected adjustable casing stabilizer (13) to be squeezed by the well wall of the inclined section (14). The central tube body (5.1) is positioned at the arc-shaped chamfer (3.5), increasing the rotational freedom of the central tube body (5.1). The universal rotating spherical surface (5.2) sits within the spherical inner wall (3.2) of the outer joint sleeve, achieving universal sliding cooperation. This allows the universal rotating spherical surface (5.2) of the second stabilizing central tube (8) to rotate around the second outer joint sleeve. The spherical inner wall (3.2) of the outer joint sleeve (9) rotates in a limited manner, thereby forming an adjustable movable connection between the upper casing (12) and the lower casing (12). Under the corrective action of the corrective sleeve rollers (2.2) of the second corrective sleeve (10) and the first corrective sleeve (2) and the joint corrective rollers (7) on the second outer joint sleeve (9) and the first outer joint sleeve (3), the upper casing (12) is successfully lowered into the inclined section (14) and the horizontal section (15). Then, other connected casings (12) are lowered in sequence, and finally the lower casing (12) is successfully lowered into the inclined section (14) and the horizontal section (15) downhole. Then, the subsequent cementing process is carried out to fix the casing string in the wellbore, and the cementing operation is completed.

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