Rolling belt type casing centralizer and using method

Abstract

The invention relates to the technical field of petroleum well completion, in particular to a rolling belt type casing centralizer and a using method. According to the technical scheme, an inner cavity of a centralizer body is a centralizer inner flow channel, multiple sets of rolling belt installation grooves and multiple sets of circulating flow channel grooves are evenly distributed in the outer wall of the centralizer body in the axial direction, a rolling belt circulating block assembly is installed in each rolling belt installation groove, and the rolling belt circulating flow channel grooves are in surface contact with the well wall through the rolling belt circulating block assemblies; and one side of each rolling belt mounting groove is provided with a circulating flow channel groove for liquid to flow up and down when the casing is lifted and lowered. The casing centralizer has the beneficial effects that rolling surface contact is formed through the rolling belt of the annular structure and the well wall, on one hand, the casing centralizing effect is well achieved, on the other hand, damage to a supporting covering film of the soft rock stratum well wall is reduced, and the problem of well wall collapse is avoided; and by arranging the circulating flow channel groove, safety accidents such as induced blowout or blowout caused by up-and-down movement of the casing pipe string can be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil well completion, in particular to a rolling belt type casing centralizer and a use method thereof. BACKGROUND

[0002] In the oil industry, drilling and well completion are important links in oil engineering, wherein well completion refers to a process of making the wellbore and the oil and gas layer effectively connected and ensuring the smooth output of oil and gas after the drilling of the oil and gas well is completed, mainly including casing lowering, well cementing, perforating, installation of production pipe column, gravel packing, sand prevention, acidizing and fracturing, etc. In the casing lowering process, in order to avoid the casing sticking in the wellbore, a casing centralizer is generally installed on the casing to support the casing and reduce the friction in the lowering process, thereby improving the well cementing quality. The existing casing centralizers include rigid centralizers, spring type centralizers and rolling centralizers. The rigid centralizer is to support the casing by sliding contact of the centralizing blocks with the well wall, the rolling centralizer is to convert the sliding contact with the well wall into rolling contact by using a spiral or straight edge with rollers, and the spring centralizer is to use an arc spring structure for sliding contact with the well wall.

[0003] In addition, the underground conditions are relatively complex, including not only hard rock layers such as granite, but also soft oil-forming rock layers such as limestone, mudstone, shale and carbonate rock layers. In the drilling process, the drilling fluid forms a supporting film on the surface of the well wall to ensure the stability of the well wall. However, when the casing or the casing centralizer is lowered, it is inevitable to collide with the well wall, especially when the casing is lowered into the inclined well or the high-angle well and the horizontal well, the well wall at the corner or the supporting film outside the well wall is easily damaged, and even the well wall collapse is caused to result in well completion failure, or the blowout is caused due to the great downhole pressure. However, the existing rigid centralizer and the spring type centralizer are directly connected with the well wall to support the casing, which has no problem when the hard rock layer is encountered, but if the lower soft rock layer is encountered, the damage and the influence are caused, and even if the rolling type casing centralizer is used, the point or line contact between the rolling ball and the well wall is still formed when the casing is lowered, which still causes the damage to the supporting film of the soft rock layer, and further causes the well wall collapse, or when the casing string is lowered into the downhole, the up and down movement is sometimes required to cause the induced blowout or blowout, thereby resulting in unnecessary loss and safety accidents. SUMMARY

[0004] The present application aims at the above-mentioned defects in the prior art, and provides a rolling belt type casing centralizer and a use method.

[0005] The rolling belt type casing centralizer provided by the present application has the technical scheme that: the casing centralizer comprises a centralizer body, a rolling belt circulating block assembly, a centralizer inner flow channel, a rolling belt mounting groove and a circulating flow channel groove; the inner cavity of the centralizer body is the centralizer inner flow channel; the outer wall of the centralizer body is uniformly distributed with a plurality of groups of rolling belt mounting grooves and a plurality of groups of circulating flow channel grooves; the rolling belt circulating block assembly is mounted in each rolling belt mounting groove; the rolling belt circulating block assembly is in surface contact with the well wall; and the circulating flow channel groove for the up-and-down flow of liquid when the casing is run in or pulled out is arranged on one side of each rolling belt mounting groove.

[0006] Preferably, the bearing shaft penetrates through the two side walls of the rolling belt mounting groove, and a pressure bearing total bearing is mounted on the two sides of the bearing shaft in the rolling belt mounting groove; a bearing shaft positioning pin is mounted at the end of the bearing shaft outside the rolling belt mounting groove; and a pressure bearing total bearing limiting clamp spring is mounted on the outer side of each pressure bearing total bearing.

[0007] Preferably, the rolling belt mounting groove has a rectangular structure; the length of the bearing shaft is greater than the width of the rolling belt mounting groove; and a bolt hole is arranged at each end of the bearing shaft for mounting the bearing shaft positioning pin.

[0008] Preferably, the rolling belt circulating block comprises a circulating block body, a circulating block inner protrusion, a circulating block male head and a circulating block female head; the outer side of the circulating block body has a planar structure; the other side has a trapezoidal structure of the circulating block inner protrusion; the front end of the circulating block body is the circulating block male head; and the rear end of the circulating block body is the circulating block female head.

[0009] Preferably, the inner walls of the male and female heads of the circulation block are respectively provided with circulation block connecting pin holes, which are used to insert circulation block connecting pins to lock the two sets of rolling belt circulation blocks when they are connected.

[0010] Preferably, the meshing gear includes a gear body, a power foot, a moving needle roller mounting hole, and a bearing shaft mounting hole. Multiple power feet are evenly distributed around the circumference of the gear body. The power feet are used to engage with the trapezoidal groove formed between the protrusions in each pair of circulating blocks to push the rolling belt circulating blocks to move their positions. The center of the gear body is provided with a bearing shaft mounting hole, and a ring of moving needle roller mounting holes is evenly distributed around the circumference of the bearing shaft mounting hole on the inner wall of the gear body.

[0011] Preferably, the aforementioned moving needle mounting hole is a semi-circular hole structure, with each moving needle inserted into the semi-circular hole structure; and the outer diameter of the bearing shaft is smaller than the inner diameter of the bearing shaft mounting hole, with the bearing shaft inserted into the bearing shaft mounting hole and making rolling contact with the moving needle.

[0012] A liquid flow guiding device is fixedly installed on the outside of each circulating flow channel. The liquid flow guiding device includes a liquid flow guiding body, an upper guide plate and a lower guide plate. The liquid flow guiding body is a long strip structure or an arc structure. An upper guide plate extending inward is provided at the top of the liquid flow guiding body, and a lower guide plate extending inward is provided at the bottom of the liquid flow guiding body.

[0013] The method of using the rolling belt sleeve centralizer mentioned in this invention includes the following steps: I. Assemble the rolling belt sleeve centralizer First, insert the male end of one rolling belt circulation block into the female end of another rolling belt circulation block, then insert the connecting pin to lock it in place, and connect them sequentially to form a ring-shaped rolling belt. Next, place this ring-shaped rolling belt into one of the multiple rolling belt mounting slots axially arranged on the outer wall of the centralizer body. Then, install multiple sets of meshing gears and bearing shafts sequentially in this rolling belt mounting slot. A ring of moving needle rollers is then installed between the bearing shaft and the meshing gears, engaging with the meshing gears through the trapezoidal grooves formed between the protrusions on the inner sides of every two rolling belt circulation blocks. Next, install pressure bearing assemblies on both sides of the bearing shaft in the rolling belt mounting slot, and install bearing shaft positioning pins at the ends of the bearing shaft outside the rolling belt mounting slot. Finally, install the remaining ring-shaped rolling belts in the rolling belt mounting slots sequentially, completing the assembly of the entire rolling belt type sleeve centralizer. 2. Connect the casings together using casing couplings to form a casing string. Assemble one or more sets of rolling belt casing centralizers and install them on the casing to be run into the well. Install a blind plug at the bottom of the casing. Then, run the casing string down into the well. When one side of the rolling belt casing centralizer contacts the well wall, the annular rolling belt on that side forms a rolling surface contact with the supporting film on the well wall surface. One or more rolling belt circulation blocks in contact with the well wall drive the meshing gears to rotate, which in turn drives the entire annular rolling belt to rotate, thus achieving the casing centralization function and disengaging from contact. The supporting membrane on the well wall surface continues to move downwards along the well wall. When it encounters a bend in an inclined well, a highly inclined well, or a horizontal well, the contacting rolling belt circulation block drives the meshing gear to rotate, which in turn drives the entire annular rolling belt structure to rotate, thus smoothly leaving the well wall at the bend and continuing to descend to the designed position. The rolling belt circulation block adopts a composite structure of a hard alloy outer layer and an elastic polymer inner layer to provide cushioning, reduce contact stress, and avoid or reduce damage to the supporting membrane on the well wall surface, especially reducing damage to the supporting membrane of the well wall in soft rock formations.

[0014] Preferably, the outer wall of the centralizer body is axially evenly distributed with three to six sets of rolling belt mounting grooves and circulation channel grooves. Each rolling belt mounting groove contains an annular rolling belt, and the outer wall of the annular rolling belt extends out of the rolling belt mounting groove, so that the annular rolling belt forms a rolling surface contact with the well wall.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The rolling belt casing centralizer mentioned in this invention, after being connected to the casing and run into the well, when one side of the rolling belt casing centralizer contacts the well wall, the annular rolling belt on that side forms a rolling surface contact with the supporting film on the well wall surface. Compared with the point contact or line contact of the prior art, the contact area with the well wall is greatly increased, which can significantly reduce local stress concentration. In addition, since the outer surface of the annular rolling belt is a smooth surface, and one or more rolling belt circulation blocks in contact with the well wall drive the meshing gear to rotate, thereby driving the entire annular rolling belt to rotate, it not only achieves the casing centralization function, but also greatly increases the contact area, reduces the squeezing effect on the supporting film on the well wall surface, protects the supporting film, and the rolling friction coefficient is lower than the sliding friction, which can reduce the friction resistance during casing running and improve the running efficiency. Furthermore, its structure is stable, which enhances the stability of the casing in the wellbore and reduces the risk of deviation. Furthermore, when encountering inclined wells, highly inclined wells, or bends in horizontal wells, the contacting rolling belt circulation block drives the meshing gear to rotate, which in turn drives the entire annular rolling belt to rotate, thus smoothly leaving the well wall at the bend, reducing damage to the supporting film on the well wall surface, especially reducing damage to the supporting film on the well wall of soft rock strata, and also avoiding the problem of well wall collapse, thus preventing accidents. In addition, by setting up multiple sets of circulation channels, the fluid in the well can flow up and down through the circulation channels, reducing the negative pressure on the formation during casing movement and avoiding safety accidents such as blowouts or induced blowouts caused by excessive negative pressure when moving the casing string up and down. Furthermore, a fluid flow guiding device can be added to the circulation channels to make the fluid spray in a specific direction under pressure, specifically towards the outer wall of the casing, rather than directly towards the well wall, thereby reducing the scouring effect on the well wall and better protecting the supporting film. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the half-section structure of the present invention; Figure 2 This is a schematic diagram of the structure of the centralizer body; Figure 3 This is a schematic diagram of the AA cross-section of the centralizer body without the fluid flow guiding device installed; Figure 4 This is a side view of the circulating block of the rolling belt; Figure 5 This is a top view of the structure of the rolling belt circulation block; Figure 6 This is a side view of the three sets of rolling belt circulation blocks; Figure 7 This is a top view of the structure of three sets of rolling belt circulation blocks; Figure 8 This is a schematic diagram of the connection between the annular rolling belt and the meshing gear; Figure 9 This is a schematic diagram of the meshing gears; Figure 10 This is a schematic diagram of the structure when the invention is applied downhole; Figure 11 This is a schematic diagram of the cross-sectional structure of the stabilizer body with an added fluid flow guiding device; Figure 12 This is a schematic diagram of the longitudinal side structure of the fluid flow guiding device; In the diagram: 1. Centralizer body; 2. Bearing shaft; 3. Meshing gear; 4. Moving needle roller; 5. Rolling belt circulation block; 6. Circulation block connecting pin; 7. Bearing shaft positioning pin; 8. Pressure bearing assembly; 9. Pressure bearing assembly limiting circlip; 10. Annular rolling belt; 11. Centralizer inner flow channel; 12. Rolling belt mounting groove; 13. Circulation flow channel groove; 14. Assembly hole; 15. Fluid flow guiding device; 3.1 Gear body; 3.2 Power foot; 3.3 Moving needle roller mounting hole; 3.4 Bearing shaft mounting hole; 5.1 Circulation block body; 5.2 Circulation block inner protrusion; 5.3 Circulation block male head; 5.4 Circulation block female head; 5.5 Circulation block connecting pin hole; 5.6 Trapezoidal groove; 15.1 Fluid flow guiding body; 15.2 Upper guide plate; 15.3 Lower guide plate; 15.3 Casing i; Rolling belt type casing centralizer ii; Casing coupling iii; Blind plug iv; Support film v; Soft rock formation well wall vi. Detailed Implementation

[0017] 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.

[0018] Example 1, referring to Figures 1-10 The present invention discloses a rolling belt casing centralizer, comprising a centralizer body 1, a rolling belt circulation block assembly, a centralizer inner flow channel 11, a rolling belt mounting groove 12, and a circulation channel groove 13. The inner cavity of the centralizer body 1 forms the centralizer inner flow channel 11. Multiple sets of rolling belt mounting grooves 12 and multiple sets of circulation channel grooves 13 are axially and evenly distributed on the outer wall of the centralizer body 1. This embodiment uses six sets as an example. A rolling belt circulation block assembly is installed in each rolling belt mounting groove 12, forming a surface contact with the well wall. One side of each rolling belt mounting groove 12 is provided for fluid flow during casing tripping. The moving circulation channel groove 13; the rolling belt circulation block assembly includes a bearing shaft 2, meshing gears 3, moving needle rollers 4, rolling belt circulation blocks 5, and circulation block connecting pins 6. Multiple sets of rolling belt circulation blocks 5 are connected by circulation block connecting pins 6 to form an annular rolling belt 10. The inner side of the annular rolling belt 10 is connected to multiple meshing gears 3. The middle part of each meshing gear 3 is installed on the assembly holes 14 on both sides of the rolling belt mounting groove 12 through the bearing shaft 2. A ring of moving needle rollers 4 is installed between the bearing shaft 2 and the meshing gears 3, so that the annular rolling belt 10 completes the rolling movement under the rotation of the meshing gears 3.

[0019] The aforementioned bearing shaft 2 passes through the two side walls of the rolling belt mounting groove 12, and pressure bearing assemblies 8 are respectively installed on both sides of the bearing shaft 2 inside the rolling belt mounting groove 12, while bearing shaft positioning pins 7 are respectively installed at the ends of the bearing shaft 2 outside the rolling belt mounting groove 12.

[0020] Pressure bearing assembly limit snap rings 9 are installed on the outer side of each pressure bearing assembly 8.

[0021] The aforementioned rolling belt mounting groove 12 is a rectangular structure. The length of the bearing shaft 2 is greater than the width of the rolling belt mounting groove 12, and pin holes are provided at both ends of the bearing shaft 2 for installing the bearing shaft positioning pins 7. In addition, it should be noted that the outer wall of the installed annular rolling belt 10 extends to the outside of the rolling belt mounting groove 12, protruding a portion, so that the annular rolling belt 10 preferentially contacts the well wall to achieve the straightening effect of surface contact.

[0022] In addition, a circulation channel 13 is provided on one side of the rolling belt installation groove 12. Its function is: when the casing string is being lowered into the well, sometimes it gets stuck and needs to be moved upward. At this time, negative pressure will appear at the bottom of the well, which can easily lead to blowout or blowout accidents. Therefore, the circulation channel 13 can facilitate the smooth passage of liquid, reduce negative pressure, and thus reduce the occurrence of blowout or blowout accidents.

[0023] Reference Figures 4-5 The rolling belt circulation block 5 mentioned in this invention includes a circulation block body 5.1, a circulation block inner protrusion 5.2, a circulation block male head 5.3, and a circulation block female head 5.4. The outer side of the circulation block body 5.1 is a planar structure, while the other side of the circulation block inner protrusion 5.2 is a trapezoidal structure. The circulation block male head 5.3 is located at the front end of the circulation block body 5.1, and the circulation block female head 5.4 is located at the rear end of the circulation block body 5.1. Furthermore, the outer side of each circulation block body 5.1 is a smooth planar structure, and the outer surface of the annular rolling belt 10 formed when connected as a whole is also a smooth planar structure. (Refer to...) Figure 8 This allows for rolling surface contact with the well wall surface, reducing the destructive effect on the well wall surface.

[0024] In addition, the inner walls of the male head 5.3 and the female head 5.4 of the circulating block mentioned in this invention are respectively provided with a circulating block connecting pin hole 5.5, which is used to insert the circulating block connecting pin 6 to lock the two sets of rolling belt circulating blocks 5 when they are connected, so as to facilitate connection and fixation.

[0025] Reference Figures 6-7Taking the connection of three sets of rolling belt circulation blocks 5 as an example, the male end 5.3 of the middle set of rolling belt circulation blocks 5 is inserted into the female end 5.4 of the previous set of rolling belt circulation blocks 5, and then the connection is achieved through the circulation block connecting pin 6. The female end 5.4 of the middle set of rolling belt circulation blocks 5 is inserted into the male end 5.3 of the next set of rolling belt circulation blocks 5, and the connection is also achieved through the circulation block connecting pin 6. The inner protrusions 5.2 of the two sets of circulation blocks connected in sequence form a trapezoidal groove 5.6, which is used to mesh with the meshing gear 3, so as to achieve a flat connection of the outer end face of the circulation block body 5.1, and then move on the well wall to achieve rolling surface contact.

[0026] Reference Figure 9 The meshing gear 3 mentioned in this invention includes a gear body 3.1, a power foot 3.2, a moving needle roller mounting hole 3.3, and a bearing shaft mounting hole 3.4. Multiple power feet 3.2 are evenly distributed in the circumferential direction of the gear body 3.1. The power feet 3.2 are used to cooperate with the trapezoidal grooves 5.6 formed between the protrusions 5.2 in each pair of circulating blocks to push the rolling belt circulating blocks 5 to move their positions. The bearing shaft mounting hole 3.4 is provided at the center of the gear body 3.1, and a ring of moving needle roller mounting holes 3.3 are evenly distributed in the circumferential direction of the bearing shaft mounting hole 3.4 on the inner wall of the gear body 3.1.

[0027] The aforementioned moving needle roller mounting hole 3.3 is a semi-circular hole structure, and each moving needle roller 4 is inserted into the semi-circular hole structure; and the outer diameter of the bearing shaft 2 is smaller than the inner diameter of the bearing shaft mounting hole 3.4, and the bearing shaft 2 is inserted into the bearing shaft mounting hole 3.4 and makes rolling contact with the moving needle roller 4.

[0028] The method of using the rolling belt sleeve centralizer mentioned in this invention includes the following steps: I. Assemble the rolling belt sleeve centralizer First, insert the male end 5.3 of one rolling belt circulation block 5 into the female end 5.4 of another rolling belt circulation block 5, and then insert the circulation block connecting pin 6 to lock it in place, thus forming a ring-shaped rolling belt 10. Next, place this ring-shaped rolling belt 10 into one of the multiple rolling belt mounting grooves 12 axially arranged on the outer wall of the stabilizer body 1. Then, install multiple sets of meshing gears 3 and bearing shafts 2 sequentially in this rolling belt mounting groove 12, with the bearing shaft 2 and the meshing gears 3... Then, install another ring of moving needle rollers 4, which mesh with the meshing gear 3 through the trapezoidal groove 5.6 formed between the protrusions 5.2 inside the circulation blocks on the inner side of every two rolling belt circulation blocks 5; then, install pressure bearing assemblies 8 on both sides of the bearing shaft 2 in the rolling belt mounting groove 12, and install bearing shaft positioning pins 7 on the ends of the bearing shaft 2 outside the rolling belt mounting groove 12; then, install the remaining annular structure rolling belts 10 in the rolling belt mounting groove 12 in sequence to complete the assembly of the entire rolling belt type sleeve centralizer ii; II. Reference Figure 10 The casing i is connected to the casing i via casing coupling iii to form a casing string. One or more sets of rolling belt casing centralizers ii are assembled and installed on the casing i to be run into the well. A blind plug iv is installed at the bottom of the casing i. The casing string is then run into the well. When one side of the rolling belt casing centralizer ii contacts the well wall, the annular rolling belt 10 on that side forms a rolling surface contact with the support film v on the well wall surface. One or more rolling belt circulation blocks 5 in contact with the well wall drive the meshing gear 3 to rotate, thereby driving the entire annular rolling belt 10 to rotate. This achieves the centralizing effect of the casing i, and it disengages from the support film v on the well wall surface, continuing to move downwards along the well wall. When encountering a deviated well, a highly deviated well, or a bend in a horizontal well, the contacting rolling belt circulation blocks 5 drive the meshing gear... The rotation of wheel 3 drives the entire annular rolling belt 10 to rotate, thus smoothly leaving the well wall at the turning point and continuing to descend to the designed position. The rolling belt circulation block 5 adopts a composite structure of hard alloy outer layer and elastic polymer inner layer to provide buffer, enhance the toughness of the structure, reduce contact stress, and avoid or reduce damage to the support film v on the well wall surface, especially to the support film v of soft rock formations such as limestone, mudstone, shale, and carbonate rock formations. It also avoids the problem of well wall collapse and reduces the occurrence of blowout or blowout accidents. In addition, by providing multiple sets of circulation channel grooves 13, the liquid can pass through the circulation channel grooves 13 up and down, reducing the negative pressure effect and avoiding safety accidents such as blowout or blowout caused by excessive negative pressure when moving the casing string up and down.

[0029] Example 2: A rolling belt casing centralizer mentioned in this invention includes a centralizer body 1, a rolling belt circulation block assembly, a centralizer inner flow channel 11, a rolling belt mounting groove 12, and a circulation channel groove 13. The inner cavity of the centralizer body 1 forms the centralizer inner flow channel 11. Multiple sets of rolling belt mounting grooves 12 and multiple sets of circulation channel grooves 13 are axially and evenly distributed on the outer wall of the centralizer body 1. A rolling belt circulation block assembly is installed in each rolling belt mounting groove 12, forming a surface contact with the well wall. One side of each rolling belt mounting groove 12 is provided for the vertical flow of fluid during casing installation and removal. The circulating flow channel 13; the rolling belt circulating block assembly includes a bearing shaft 2, meshing gears 3, moving needle rollers 4, rolling belt circulating blocks 5, and circulating block connecting pins 6. Multiple sets of rolling belt circulating blocks 5 are connected by circulating block connecting pins 6 to form an annular rolling belt 10. The inner side of the annular rolling belt 10 is connected to multiple meshing gears 3. The middle part of each meshing gear 3 is installed on the assembly holes 14 on both sides of the rolling belt mounting groove 12 through the bearing shaft 2. A ring of moving needle rollers 4 is installed between the bearing shaft 2 and the meshing gears 3, so that the annular rolling belt 10 completes the rolling movement under the rotation of the meshing gears 3.

[0030] The difference from Example 1 is: In this embodiment, three sets of rolling belt mounting grooves 12 and circulation channel grooves 13 are evenly distributed axially on the outer wall of the centralizer body 1. This can also basically achieve the centralizing effect on the casing i. Each rolling belt mounting groove 12 still has an annular rolling belt 10 installed in it, and the outer wall of the annular rolling belt 10 extends out of the rolling belt mounting groove 12, so that the annular rolling belt 10 forms a rolling surface contact with the well wall. This not only plays the role of centralizing the casing i, but also reduces the damage to the support film v on the surface of the well wall, especially the damage to the support film v of the soft rock well wall vi.

[0031] Example 3: A rolling belt casing centralizer mentioned in this invention includes a centralizer body 1, a rolling belt circulation block assembly, a centralizer inner flow channel 11, a rolling belt mounting groove 12, and a circulation channel groove 13. The inner cavity of the centralizer body 1 forms the centralizer inner flow channel 11. Multiple sets of rolling belt mounting grooves 12 and multiple sets of circulation channel grooves 13 are axially and evenly distributed on the outer wall of the centralizer body 1. A rolling belt circulation block assembly is installed in each rolling belt mounting groove 12, forming a surface contact with the well wall. One side of each rolling belt mounting groove 12 is provided for the vertical flow of fluid during casing installation and removal. The circulating flow channel 13; the rolling belt circulating block assembly includes a bearing shaft 2, meshing gears 3, moving needle rollers 4, rolling belt circulating blocks 5, and circulating block connecting pins 6. Multiple sets of rolling belt circulating blocks 5 are connected by circulating block connecting pins 6 to form an annular rolling belt 10. The inner side of the annular rolling belt 10 is connected to multiple meshing gears 3. The middle part of each meshing gear 3 is installed on the assembly holes 14 on both sides of the rolling belt mounting groove 12 through the bearing shaft 2. A ring of moving needle rollers 4 is installed between the bearing shaft 2 and the meshing gears 3, so that the annular rolling belt 10 completes the rolling movement under the rotation of the meshing gears 3.

[0032] The difference from Example 2 is: Reference Figure 11 A liquid flow guide device 15 is fixedly installed on the outside of each circulating flow channel 13, as shown in the reference. Figure 12 The fluid flow guiding device 15 includes a fluid flow guiding body 15.1, an upper guide plate 15.2, and a lower guide plate 15.3. The fluid flow guiding body 15.1 has a long strip-shaped or arc-shaped structure. The upper guide plate 15.2 extending inward is provided at the top of the fluid flow guiding body 15.1, and the lower guide plate 15.3 extending inward is provided at the bottom of the fluid flow guiding body 15.1. The function of the upper guide plate 15.2 is: when the casing string moves downward, the fluid in the wellbore is sprayed upward along the circulation channel 13. The upper guide plate 15.2 guides the gushing liquid to the outer wall of the casing, reducing the scouring effect on the well wall. Similarly, the function of the lower guide plate 15.3 is that when the casing string needs to be lifted to a higher position, the liquid in the wellbore gushes downward along the circulation channel 13. The lower guide plate 15.3 guides the gushing liquid to the outer wall of the casing, reducing the scouring effect on the well wall and avoiding damage to the well wall. In addition, it also avoids safety accidents such as induced blowout or blowout caused by excessive negative pressure.

[0033] 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. A rolling belt type sleeve centralizer, comprising a centralizer body (1), characterized in that: It also includes a rolling belt circulation block assembly, a centralizer internal flow channel (11), a rolling belt mounting groove (12), and a circulation channel groove (13). The internal flow channel (11) is located in the inner cavity of the centralizer body (1). Multiple sets of rolling belt mounting grooves (12) and multiple sets of circulation channel grooves (13) are evenly distributed axially on the outer wall of the centralizer body (1). A rolling belt circulation block assembly is installed in each rolling belt mounting groove (12) and forms a surface contact with the well wall through the rolling belt circulation block assembly. A circulation channel groove (13) for fluid to flow up and down when the casing (i) is provided on one side of each rolling belt mounting groove (12). The rolling belt circulation block assembly includes a bearing... Shaft (2), meshing gear (3), moving needle roller (4), rolling belt circulation block (5), circulation block connecting pin (6), multiple sets of rolling belt circulation blocks (5) are connected by circulation block connecting pin (6) to form an annular structure rolling belt (10). The inner side of the annular structure rolling belt (10) is connected to multiple meshing gears (3). The middle part of each meshing gear (3) is installed on the assembly holes (14) on both sides of the rolling belt mounting groove (12) through the bearing shaft (2). A ring of moving needle roller (4) is installed between the bearing shaft (2) and the meshing gear (3) so that the annular structure rolling belt (10) completes the rolling movement under the rotation of the meshing gear (3).

2. The rolling belt sleeve centralizer according to claim 1, characterized in that: The bearing shaft (2) passes through the two side walls of the rolling belt mounting groove (12), and pressure bearing assemblies (8) are installed on both sides of the bearing shaft (2) inside the rolling belt mounting groove (12). Bearing shaft positioning pins (7) are installed at the ends of the bearing shaft (2) outside the rolling belt mounting groove (12), and pressure bearing assemblies limiting snap rings (9) are installed on the outside of each pressure bearing assembly (8).

3. The rolling belt type sleeve centralizer according to claim 2, characterized in that: The rolling belt mounting groove (12) is a rectangular structure. The length of the bearing shaft (2) is greater than the width of the rolling belt mounting groove (12). The bearing shaft (2) has pin holes at both ends for mounting the bearing shaft positioning pins (7).

4. The rolling belt type sleeve centralizer according to claim 3, characterized in that: The rolling belt circulation block (5) includes a circulation block body (5.1), a circulation block inner protrusion (5.2), a circulation block male head (5.3), and a circulation block female head (5.4). The outer side of the circulation block body (5.1) is a planar structure, and the other side is a trapezoidal structure of the circulation block inner protrusion (5.2). The front end of the circulation block body (5.1) is the circulation block male head (5.3), and the rear end of the circulation block body (5.1) is the circulation block female head (5.4).

5. The rolling belt type sleeve centralizer according to claim 4, characterized in that: The inner walls of the male head (5.3) and female head (5.4) of the circulation block are respectively provided with circulation block connecting pin holes (5.5), which are used to insert circulation block connecting pins (6) to lock the two sets of rolling belt circulation blocks (5) when they are connected.

6. The rolling belt type sleeve centralizer according to claim 5, characterized in that: The meshing gear (3) includes a gear body (3.1), a power foot (3.2), a moving needle roller mounting hole (3.3), and a bearing shaft mounting hole (3.4). Multiple power feet (3.2) are evenly distributed in the circumferential direction of the gear body (3.1). The power feet (3.2) are used to cooperate with the trapezoidal groove (5.6) formed between the protrusions (5.2) in each pair of circulating blocks to push the rolling belt circulating block (5) to move its position. The center of the gear body (3.1) is provided with a bearing shaft mounting hole (3.4). A ring of moving needle roller mounting holes (3.3) is evenly distributed in the circumferential direction of the bearing shaft mounting hole (3.4) on the inner wall of the gear body (3.1).

7. The rolling belt type sleeve centralizer according to claim 6, characterized in that: The mounting hole (3.3) for the moving needle rollers is a semi-circular hole structure, and each moving needle roller (4) is inserted into the semi-circular hole structure. The outer diameter of the bearing shaft (2) is smaller than the inner diameter of the bearing shaft mounting hole (3.4). The bearing shaft (2) is inserted into the bearing shaft mounting hole (3.4) and makes rolling contact with the moving needle roller (4).

8. The rolling belt type sleeve centralizer according to claim 7, characterized in that: The rolling belt circulation block (5) in the annular rolling belt (10) adopts a composite structure of a hard alloy outer layer and an elastic polymer inner layer. The outer layer is a wear-resistant hard alloy outer layer, and the elastic polymer inner layer is a silicon-based elastomer used to provide cushioning and reduce contact stress.

9. The rolling belt type sleeve centralizer according to claim 8, characterized in that: in A liquid flow guide device (15) is fixedly installed on the outside of each circulating flow channel (13). The liquid flow guide device (15) includes a liquid flow guide body (15.1), an upper guide plate (15.2) and a lower guide plate (15.3). The liquid flow guide body (15.1) is a long strip structure or an arc structure. An upper guide plate (15.2) extending inward is provided at the top of the liquid flow guide body (15.1), and a lower guide plate (15.3) extending inward is provided at the bottom of the liquid flow guide body (15.1).

10. The method of using the rolling belt sleeve centralizer according to claim 8, characterized in that: Includes the following processes: I. Assemble the rolling belt sleeve centralizer (ii) First, insert the male end (5.3) of one rolling belt circulation block (5) into the female end (5.4) of another rolling belt circulation block (5), and then insert the circulation block connecting pin (6) to lock it in place, thus forming a ring-shaped rolling belt (10); then, place this ring-shaped rolling belt (10) into one of the multiple rolling belt mounting grooves (12) axially arranged on the outer wall of the stabilizer body (1); then, install multiple sets of meshing gears (3) and bearing shafts (2) in this rolling belt mounting groove (12), with the bearing shaft (2) and the meshing gears (3) connected in sequence. Then, install another ring of moving needle rollers (4) and mesh with the meshing gear (3) through the trapezoidal groove (5.6) formed between the protrusions (5.2) on the inner side of each two rolling belt circulation blocks (5); then, install pressure bearing assemblies (8) on both sides of the bearing shaft (2) in the rolling belt mounting groove (12), and install bearing shaft positioning pins (7) on the ends of the bearing shaft (2) outside the rolling belt mounting groove (12); then, install the remaining annular structure rolling belts (10) in the rolling belt mounting groove (12) in sequence to complete the assembly of the entire rolling belt sleeve centralizer (ii); 2. Connect casing (i) to casing (i) using casing coupling (iii) to form a casing string. Assemble one or more sets of rolling belt casing centralizers (ii) and install them on the casing (i) to be run into the well. Install blind plug (iv) at the bottom of casing (i). Then run the casing string into the well. When one side of the rolling belt casing centralizer (ii) contacts the well wall, the annular rolling belt (10) on that side forms a rolling surface contact with the support film (v) on the well wall surface. Among them, one or more rolling belt circulation blocks (5) in contact with the well wall drive the meshing gear (3) to rotate, thereby driving the entire annular rolling belt (10) to rotate, thus realizing the rotation of casing (i). The device acts as a straightener and disengages from the support membrane (v) on the surface of the well wall, continuing to move downwards along the well wall. When encountering a bend in an inclined well, a highly inclined well, or a horizontal well, the contacting rolling belt circulation block (5) drives the meshing gear (3) to rotate, which in turn drives the entire annular rolling belt (10) to rotate, thus smoothly leaving the well wall at the bend and continuing to descend to the designed position. The rolling belt circulation block (5) adopts a composite structure of a hard alloy outer layer and an elastic polymer inner layer to provide buffering, reduce contact stress, and avoid or reduce damage to the support membrane (v) on the surface of the well wall, especially reducing damage to the support membrane (v) on the soft rock well wall (vi).

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