A casing centralizer with well wall virtual mud cake cleaning function

Abstract

The present disclosure relates to the technical field of casing centralizer, and one embodiment of the present disclosure provides a casing centralizer with well wall virtual mud cake removing function, which comprises a centralizer body, further comprises a fixing ring, a scraper, a cleaning mechanism and an adjusting mechanism, the fixing ring is provided with two, the two fixing rings are fixedly connected at the two ends of the centralizer body respectively, a plurality of scrapers are arranged on the two fixing rings through a plurality of moving mechanisms, the moving mechanism is used for driving the position of the scraper to move, the cleaning mechanism is arranged on each scraper and is used for scraping off the well wall virtual mud cake, the adjusting mechanism is provided with two, and the two adjusting mechanisms are used for driving the corresponding moving mechanism to operate, through the above technical scheme, the technical problem that the existing technology is used for solving the pre-down mud cake scraping device in the well or the method of cleaning the well wall virtual mud cake by using the drilling fluid circulation, and then the casing and the casing centralizer are down, and the cleaning method affects the drilling operation efficiency.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the field of casing centralizer technology, and more specifically, to a casing centralizer with a wellbore mud cake removal function. Background Technology

[0002] The casing centralizer is a core component of the oil and gas well casing string. Its design and application must be precisely adapted to the casing string specifications, wellbore trajectory, and operating conditions. Utilizing specific mechanical structures such as elastic centralizer bodies and rigid centralizer wings, the casing centralizer reliably connects to the casing string. Throughout the entire process of running the casing string into the wellbore, it supports the casing according to the wellbore diameter, ensuring that the casing string remains centered within the wellbore. In critical cementing operations during drilling, precise radial positioning effectively controls the casing's eccentricity within the wellbore, preventing annular space formation caused by casing adhering to the wellbore wall. In addition to addressing unevenness issues, its optimized flow channel design reduces the flow resistance of drilling fluid in the annular space, significantly improving the displacement efficiency of cement slurry on drilling fluid and ensuring the formation of a continuous and dense cement sheath bonding interface between the casing and the well wall. Furthermore, for complex well conditions such as deep wells and horizontal wells, the casing centralizer can disperse the radial load generated by the casing string's own weight, reduce the bending stress of the casing string, and prevent fatigue damage to the casing caused by long-term bending. It provides a key guarantee for the long-term safe service of the casing string and is an indispensable technical equipment for achieving safe and efficient drilling and cementing operations.

[0003] During drilling operations, the wellbore surface is easily affected by a combination of factors, including drilling fluid performance parameters (such as viscosity, shear force, and solid content), wellbore rock mechanical properties (such as porosity and cementation strength), and drilling process operations (such as flow rate control and tripping speed). This results in the formation of loose mud cakes on the wellbore surface. Loose mud cakes are characterized by loose structure, low cementation strength, and poor stability. They are prone to peeling off under external forces, making it difficult to provide a stable radial support foundation for the casing centralizer. This may affect the centralizer's centering effect on the casing string. Therefore, it is necessary to clean the loose mud cakes on the wellbore.

[0004] Currently, the conventional methods for dealing with loose mud cake on the well wall require the pre-installation of a special mud cake scraping tool in the well. The tool removes the loose mud cake from the well wall surface through axial movement and radial scraping. Alternatively, the drilling fluid circulation parameters (such as increasing the circulation rate and optimizing the rheological properties of the drilling fluid) are adjusted to utilize the flushing and carrying effect of the drilling fluid in the annular space to suspend and discharge the loose mud cake. However, both of these methods need to be implemented separately before the casing string and casing centralizer are installed, which prolongs the drilling operation process, is more time-consuming and labor-intensive, and reduces the efficiency of drilling operations. Summary of the Invention

[0005] To overcome the above-mentioned defects, the embodiments of this disclosure provide a casing centralizer with a wellbore mud cake removal function, which solves the technical problem that the existing method of cleaning the wellbore mud cake by first running a mud cake scraper or using drilling fluid circulation cleaning method before running the casing and casing centralizer has a relatively large impact on drilling operation efficiency.

[0006] According to one aspect, at least one embodiment of this disclosure provides a casing centralizer with a wellbore mud cake removal function, including a centralizer body, and further including: a fixing ring, a scraper, a cleaning mechanism, and an adjusting mechanism. Two fixing rings are provided, each fixedly connected to both ends of the centralizer body. Multiple scrapers are provided on each of the two fixing rings via multiple moving mechanisms. The moving mechanisms are used to drive the scrapers to move. Each scraper is provided with a cleaning mechanism for scraping off the wellbore mud cake. Two adjusting mechanisms are provided, each used to drive the corresponding moving mechanism to operate.

[0007] To drive the scraper to move on the fixed ring, the moving mechanism includes: a sliding box, a moving rod, and a support spring. The sliding box is fixedly connected to the fixed ring, one end of the moving rod is fixedly connected to the scraper, and the moving rod is slidably connected in the sliding box through a sliding assembly. Two support springs are provided, and both support springs are provided on the moving rod.

[0008] To increase the stability of the moving rod during movement, the sliding assembly includes a sliding rod and a sliding groove. The sliding rod is fixedly connected inside the sliding box, and the sliding groove is formed on the moving rod. The sliding rod is slidably connected inside the sliding groove. Both of the support springs are located inside the sliding groove. One end of each support spring is fixedly connected to the sliding rod, and the other end of the support spring is fixedly connected to the inner wall of the sliding groove.

[0009] To adjust the extension length of the moving rod to accommodate wells of different diameters, the adjustment mechanism includes a rotating ring, adjusting plates, adjusting shafts, and a limiting assembly. The rotating ring is rotatably connected to the centralizer body. Multiple adjusting plates are provided, and each adjusting plate is fixedly connected to the rotating ring. Each moving rod is rotatably connected to an adjusting shaft, and each adjusting plate contacts a corresponding adjusting shaft. The limiting assembly is provided on the rotating ring to fix and limit the position of the rotating ring.

[0010] To limit and fix the position of the rotating ring after rotation, and to prevent it from rotating again after adjustment, thus affecting the adjustment effect, the limiting component includes: a limiting plate and a locking screw. There are two limiting plates, both of which are fixedly connected to the rotating ring. There are two locking screws, and each of the two limiting plates has a screw hole. The two locking screws are threaded into the two screw holes respectively.

[0011] In order to scrape off the loose mud cake on the well wall, the cleaning mechanism includes: scrapers and wire brushes. Multiple scrapers are fixedly connected to the surface of each scraper, and multiple sets of wire brushes are provided. Multiple wire brushes are fixedly connected to each scraper, and each set of wire brushes is respectively arranged between each pair of adjacent scrapers.

[0012] To prevent the adjusting plate from deviating when it contacts the adjusting shaft, and to ensure that the circumferential surface of the adjusting wheel is always in contact with the edge of the adjusting plate and rolls along the edge of the adjusting plate, baffles are fixedly connected to both sides of the adjusting shaft, and the opposite ends of the two baffles are in contact with the adjusting plate.

[0013] In order to provide stable support and fixation for the fixed ring, thereby facilitating the adjustment of the moving distance of the support scraper, multiple connecting rods are fixedly connected to the body of the stabilizer, and the other end of each of the multiple connecting rods is fixedly connected to the fixed ring.

[0014] In order to drive the scraper, fixing ring and centralizer body to rotate and increase the contact range between the scraper and wire brush and the well wall for cleaning, multiple scrapers and wire brushes are arranged on the scraper in an inclined state.

[0015] To facilitate the operator's turning of the locking screw, thereby enabling the locking screw to move within the screw hole on the limit plate and press the rotating ring against the body of the stabilizer, a hexagonal block is fixedly connected to the ends of the two locking screws that are far apart from each other.

[0016] The beneficial effects of the embodiments disclosed herein are as follows:

[0017] In this disclosure, by setting up a fixed ring, scraper, cleaning mechanism, moving mechanism and adjusting mechanism, the diameter of the multiple scrapers can be adjusted according to the diameter of the well wall to adapt to different specifications of well wall diameter, thereby improving the flexibility of the casing centralizer. Furthermore, when the casing centralizer moves in the well, it can clean and scrape off the loose mud cake on the well wall, thereby improving drilling and cementing efficiency. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments of this disclosure will be briefly introduced below. Obviously, the drawings described below are merely some exemplary embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the content of the exemplary embodiments of this disclosure and these drawings without any creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure in one embodiment of the present disclosure;

[0020] Figure 2This is a structural schematic diagram from another angle in one embodiment of the present disclosure;

[0021] Figure 3 This is a schematic diagram of the moving mechanism, the cleaning mechanism, and the adjusting mechanism in one embodiment of the present disclosure;

[0022] Figure 4 This is a schematic diagram of the structure of the moving mechanism in one embodiment of the present disclosure;

[0023] Figure 5 This is a schematic diagram of the structure of the adjusting mechanism in one embodiment of the present disclosure;

[0024] Figure 6 This is a schematic diagram showing the disassembled structure of the moving mechanism in one embodiment of this disclosure;

[0025] Figure 7 This is a schematic diagram of the cleaning mechanism in one embodiment of the present disclosure.

[0026] In the diagram: 1. Centralizer body; 2. Fixing ring; 3. Scraper; 4. Sliding box; 5. Moving rod; 6. Support spring; 7. Sliding rod; 8. Sliding groove; 9. Rotating ring; 10. Adjusting plate; 11. Adjusting shaft; 12. Limiting plate; 13. Locking screw; 14. Scraper; 15. Wire brush; 16. Baffle; 17. Connecting rod; 18. Hexagonal block. Detailed Implementation

[0027] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present disclosure and are not intended to limit the scope of the disclosure.

[0028] To keep the drawings concise, each drawing only schematically shows the parts relevant to the disclosure; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0029] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0030] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this disclosure.

[0032] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] like Figures 1-7 As shown, a casing centralizer with a wellbore mud cake removal function is illustrated in one embodiment of this disclosure. It includes a centralizer body 1, and further includes: a fixing ring 2, scrapers 3, a cleaning mechanism, and an adjusting mechanism. Multiple connecting rods 17 are fixedly connected to the centralizer body 1, and the other ends of each connecting rod 17 are fixedly connected to the fixing ring 2. Two fixing rings 2 are provided, each fixedly connected to one end of the centralizer body 1. Multiple scrapers 3 are provided on each of the two fixing rings 2 via multiple moving mechanisms. The moving mechanisms drive the scrapers 3 to move. Each scraper 3 is equipped with a cleaning mechanism for scraping off the wellbore mud cake. Two adjusting mechanisms are provided, each driving a corresponding moving mechanism. Through the arrangement of the fixing ring 2, scrapers 3, cleaning mechanism, moving mechanism, and adjusting mechanism, the diameter of the multiple scrapers 3 can be adjusted according to the diameter of the wellbore to accommodate different wellbore diameters. Furthermore, when the casing centralizer moves within the well, it can clean and scrape off the wellbore mud cake, improving drilling and cementing efficiency.

[0034] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 6As shown, the moving mechanism includes: a sliding box 4, a moving rod 5, and support springs 6. The sliding box 4 is fixedly connected to the fixed ring 2. One end of the moving rod 5 is fixedly connected to the scraper 3. The moving rod 5 is slidably connected to the sliding box 4 through a sliding assembly. There are two support springs 6, both of which are set on the moving rod 5. The sliding assembly includes: a sliding rod 7 and a sliding groove 8. The sliding rod 7 is fixedly connected to the sliding box 4. The sliding groove 8 is opened on the moving rod 5 and slidably connected to the sliding groove 8. Both support springs 6 are located in the sliding groove 8. One end of the two support springs 6 is fixedly connected to the sliding rod 7, and the other end of the support springs 6 is fixedly connected to the inner wall of the sliding groove 8. The moving rod 5 moves within the sliding box 4. When the moving rod 5 moves, it drives the scraper 3 to move. When the moving rod 5 moves, it moves on the sliding rod 7 through the sliding groove 8. At this time, the support springs 6 are compressed, thereby increasing the stability of the moving rod 5 when sliding.

[0035] like Figure 1 , Figure 2 , Figure 3 and Figure 5 As shown, the adjustment mechanism includes: a rotating ring 9, an adjusting plate 10, an adjusting shaft 11, and a limiting assembly. Both sides of the adjusting shaft 11 are fixedly connected to baffles 16, with the opposite ends of the two baffles 16 contacting the adjusting plate 10. The rotating ring 9 is rotatably connected to the centralizer body 1. Multiple adjusting plates 10 are provided, each fixedly connected to the rotating ring 9. Each moving rod 5 is rotatably connected to an adjusting shaft 11, and each adjusting plate 10 contacts its corresponding adjusting shaft 11. The limiting assembly is located on the rotating ring 9 and is used to fix and limit the position of the rotating ring 9. The limiting assembly includes: a limiting plate 12 and locking screws 13. The ends of the two locking screws 13 that are far apart from each other are fixedly connected to hexagonal blocks 18. The limiting plate 12 is... There are two limiting plates 12, both fixedly connected to the rotating ring 9. There are two locking screws 13, and each of the two limiting plates 12 has a screw hole. The two locking screws 13 are threaded into the two screw holes respectively. When the operator twists the rotating ring 9, it rotates on the body 1 of the centralizer. When the rotating ring 9 rotates, it drives the adjusting plate 10 to rotate synchronously with the rotating ring 9. At this time, the adjusting shaft 11 rolls on the adjusting plate 10, thereby supporting the moving rod 5 to move in the sliding box 4. After the rotating ring 9 rotates, the operator twists the hexagonal block 18 to drive the locking screws 13 to rotate. The locking screws 13 move in the screw holes opened on the limiting plates 12 and abut against the body 1 of the centralizer, thereby driving the rotating ring 9 to be fixed and limited.

[0036] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 7As shown, the cleaning mechanism includes: scrapers 14 and wire brushes 15. Multiple scrapers 14 are fixedly connected to the surface of each scraper 3, and multiple sets of wire brushes 15 are provided. Multiple wire brushes 15 are fixedly connected to each scraper 3. Each set of wire brushes 15 is respectively set between each pair of adjacent scrapers 14. Multiple scrapers 14 and wire brushes 15 are set in an inclined state on the scraper 3. When the centralizer body 1 moves in the well with the pipeline, the scrapers 14 set on the scraper 3 scrape off the loose mud cake on the well wall, and the wire brushes 15 sweep off and clean the remaining loose mud cake on the well wall.

[0037] Working principle: When it is necessary to clean the loose mud cake on the well wall, the operator twists the rotating ring 9 to rotate on the centralizer body 1. When the rotating ring 9 rotates, it drives the adjusting plate 10 to rotate synchronously with the rotating ring 9. At this time, the adjusting shaft 11 rolls on the adjusting plate 10, thereby supporting the moving rod 5 to move within the sliding box 4. When the moving rod 5 moves within the sliding box 4, it drives the scraper 3 to move. When the moving rod 5 moves, it moves on the sliding rod 7 through the sliding groove 8. At this time, the support spring... 6 is compressed, thereby increasing the stability of the moving rod 5 when sliding. After the rotating ring 9 rotates, the operator twists the hexagonal block 18 to drive the locking screw 13 to rotate. The locking screw 13 moves in the screw hole opened on the limit plate 12 and abuts against the centralizer body 1, thereby driving the rotating ring 9 to be fixed and limited. When the centralizer body 1 moves in the well with the pipeline, the scraper 14 set on the scraper 3 scrapes off the loose mud cake on the well wall, and the wire brush 15 sweeps off and cleans the remaining loose mud cake on the well wall.

[0038] It should also be noted that the scraper 14 is inclined on the scraper 3, so that when the centralizer body 1 moves in the well, the inclined scraper 14 can move in a spiral motion along the well wall, thereby driving multiple scrapers 3 and the centralizer body 1 to rotate in the well, thereby expanding the scraping range of the scraper 14, and working with the wire brush 15 to clean the well wall, thus improving the cleaning efficiency of the loose mud cake on the well wall.

[0039] It should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure and are not intended to limit it. Although this disclosure has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this disclosure without departing from the spirit and scope of the technical solutions of this disclosure, and all such modifications and substitutions should be covered within the scope of the claims of this disclosure.

Claims

1. A casing centralizer with wellbore mud cake removal function, comprising a centralizer body (1), characterized in that, Also includes: Two fixing rings (2) are provided, and the two fixing rings (2) are respectively fixedly connected to both ends of the body (1) of the straightener; The scraper (3) is provided on both of the two fixed rings (2) by a plurality of moving mechanisms. The moving mechanisms are used to drive the scraper (3) to move. Cleaning mechanism, each of the scrapers (3) is equipped with a cleaning mechanism for scraping off the loose mud cake from the well wall; The adjustment mechanism is provided in two parts, and the two adjustment mechanisms are used to drive the corresponding moving mechanism to operate. The moving mechanism includes: Sliding box (4), the sliding box (4) is fixedly connected to the fixing ring (2); A movable rod (5) is fixedly connected at one end to the scraper (3), and the movable rod (5) is slidably connected in the slide box (4) through a sliding assembly; Support spring (6), two support springs (6) are provided, and both support springs (6) are provided on the moving rod (5); The adjustment mechanism includes: Rotating ring (9), which is rotatably connected to the body (1) of the stabilizer; Adjustment plate (10), there are multiple adjustment plates (10), and multiple adjustment plates (10) are fixedly connected to the rotating ring (9); Adjustment shaft (11), each of the moving rods (5) is rotatably connected to the adjustment shaft (11), each of the adjustment plates (10) is in contact with the corresponding adjustment shaft (11), and baffles (16) are fixedly connected to both sides of the adjustment shaft (11), and the opposite ends of the two baffles (16) are in contact with the adjustment plate (10). A limiting component is disposed on the rotating ring (9) for fixing and limiting the position of the rotating ring (9); The limit components include: Limiting plate (12), two limiting plates (12) are provided, and both limiting plates (12) are fixedly connected to the rotating ring (9); There are two locking screws (13), and each of the two limiting plates (12) has a screw hole. The two locking screws (13) are threaded into the two screw holes respectively.

2. A casing centralizer with wellbore mud cake removal function according to claim 1, characterized in that, The sliding component includes: Slide rod (7), which is fixedly connected inside the slide box (4); The slide groove (8) is formed on the moving rod (5). The slide rod (7) is slidably connected in the slide groove (8). The two support springs (6) are located in the slide groove (8). One end of the two support springs (6) is fixedly connected to the slide rod (7), and the other end of the support springs (6) is fixedly connected to the inner wall of the slide groove (8).

3. A casing centralizer with wellbore mud cake removal function according to claim 1, characterized in that, The cleaning mechanism includes: Scraper (14), a plurality of scrapers (14) are fixedly connected to the surface of each scraper (3); The wire brush (15) is provided in multiple sets. Each scraper (3) is fixedly connected with multiple wire brushes (15). Each set of wire brushes (15) is respectively arranged between each two adjacent scrapers (14).

4. A casing centralizer with wellbore mud cake removal function according to claim 1, characterized in that, Multiple connecting rods (17) are fixedly connected to the body (1) of the straightener, and the other end of each of the multiple connecting rods (17) is fixedly connected to the fixing ring (2).

5. A casing centralizer with wellbore mud cake removal function according to claim 3, characterized in that, Multiple scrapers (14) and wire brushes (15) are arranged at an angle on the scraper (3).

6. A casing centralizer with wellbore mud cake removal function according to claim 1, characterized in that, The two locking screws (13) are each fixedly connected to a hexagonal block (18) at their ends that are far apart from each other.

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